By Dr. Donald Liebell

Today, lasers are so common that it is easy to forget how extraordinary the idea once seemed. Lasers scan groceries, transmit enormous amounts of information through fiber-optic cable, manufacture microscopic electronic components, measure distance, reshape the cornea, remove tissue, coagulate blood vessels, and perform operations with extraordinary precision.

There is another branch of laser science, however, that developed along a very different path. Instead of using intense laser energy to cut, burn, vaporize, or destroy tissue, researchers discovered that carefully selected doses of low-intensity light could interact with living cells without producing a destructive thermal effect. That field has been called low-level laser therapy, LLLT, cold laser therapy, laser biostimulation, and, increasingly, photobiomodulation, or PBM.

Its history is fascinating because it did not begin with a medical device company. It began with Albert Einstein, passed through some of the most important advances in twentieth-century physics, and took an unexpected medical turn in the laboratory of a Hungarian physician named Endre Mester. Over subsequent decades, it developed into an international field of biological and medical research, eventually leading companies such as Erchonia to subject low-level laser devices to controlled clinical studies and the American regulatory process.

Today, photobiomodulation research extends from cellular physiology and musculoskeletal pain to tissue repair and other biological applications. In a very different use of low-level laser energy, the science eventually reached non-invasive body contouring. That history is particularly important now. Inexpensive red-light devices and wellness products have made almost every glowing object on the Internet look as though it belongs to the same scientific category. It does not. The story of therapeutic laser technology is much older, much more interesting, and considerably more sophisticated.

Albert Einstein never built a laser. There were no lasers to build in 1917. What Einstein did was provide one of the essential theoretical pieces that eventually made the laser possible.

In his work on the quantum theory of radiation, Einstein described fundamental ways in which matter and electromagnetic radiation could interact. One of these was stimulated emission, a concept that sounds intimidating but is remarkably elegant. 

An atom can exist in an excited energy state. Under the proper conditions, an incoming photon can stimulate that excited atom to release another photon. Critically, the newly released photon can possess the same frequency, phase, polarization, and direction as the photon that stimulated it. One photon can therefore help generate another highly organized photon.

That principle eventually made possible the amplification of light into an extraordinarily ordered beam. Forty-three years later, stimulated emission would become the heart of the first working laser.

Modern physicists recognize Einstein's 1917 work as one of the theoretical foundations of laser technology. It is difficult to imagine that Einstein could have anticipated everything that would follow. His physics ultimately contributed to technologies used in telecommunications, manufacturing, astronomy, military systems, eye surgery, dentistry, dermatology, oncology, physical medicine, and photobiomodulation.

Medical laser therapy therefore has a legitimate intellectual ancestry beginning in quantum physics.

Scientific discoveries rarely occur in one dramatic leap. During the decades following Einstein's work, physicists continued learning how atoms absorbed and emitted electromagnetic energy.

In the early 1950s, physicist Charles Townes and colleagues developed the MASER, an acronym for Microwave Amplification by Stimulated Emission of Radiation. The maser demonstrated that Einstein's theoretical principle could be transformed into a practical device.

The next challenge was obvious: Could the same thing be done with visible or infrared light? That question led directly to the laser.

The word LASER means Light Amplification by Stimulated Emission of Radiation. The acronym has become so familiar that most people no longer realize that "laser" began as a technical description of a very particular method of generating light.

On May 16, 1960, physicist Theodore Maiman successfully operated the first working laser at Hughes Research Laboratories in California. His device used a synthetic ruby crystal surrounded by a powerful flash lamp. The apparatus looked surprisingly simple, although the physics behind it certainly was not.

When stimulated, chromium atoms within the ruby produced a brief pulse of coherent red light. For the first time, Einstein's theoretical principle of stimulated emission had become a working optical device. The American Physical Society now recognizes Hughes Research Laboratories as the location where the first operational laser was demonstrated.

A new technological era had begun, although scientists did not immediately know what to do with their remarkable invention. The laser was famously described as a "solution looking for a problem." The problems were soon found. Laser technology spread into physics, engineering, military research, communications, manufacturing, measurement, surgery, and medicine. Researchers also recognized that different wavelengths, energies, exposure times, and methods of delivery could produce dramatically different biological effects. That distinction eventually became crucial to medical laser science. A laser powerful enough to cut tissue and a laser intended to influence cellular activity are both lasers, but they are not being used to accomplish remotely the same biological purpose.

Most people first encountered medical lasers through surgery. High-powered medical lasers can create concentrated thermal energy that, depending upon wavelength and operating parameters, can cut tissue, coagulate blood vessels, remove unwanted tissue, vaporize material, or create controlled thermal injury. Those effects are enormously valuable, but they are fundamentally different from what came to be known as low-level laser therapy. A low-level laser is designed so that the desired biological response is photochemical or photobiological rather than destructive heating.

The distinction is similar to the difference between using electricity to power a computer and using electricity to weld metal. Both involve electricity, but what the energy accomplishes depends upon how it is delivered. The same principle applies to light.

Wavelength matters. Power matters. Energy density matters. Exposure time matters. Pulse structure can matter. Tissue characteristics and treatment timing can matter. More light is not automatically better.

This last point is especially important because photobiomodulation frequently demonstrates what researchers call a biphasic dose response. An appropriate dose can stimulate a biological process, while excessive energy may produce little additional benefit or can inhibit the response researchers were trying to stimulate.

Photobiomodulation is therefore not simply the proposition that "light is healthy." It is the scientific study of how specific light parameters interact with biology.

The most famous early chapter in therapeutic laser history took place in Hungary. Dr. Endre Mester, a physician and surgical researcher at Semmelweis University in Budapest, began investigating the biological effects of laser radiation during the 1960s. This is also where an often-repeated version of laser history needs correction. Mester is frequently described as having attempted to cure cancer in laboratory rats when he accidentally discovered that wounds healed faster. That description captures the general spirit of what happened, but it compresses several stages of research into one event.

Mester was studying whether low-power ruby laser irradiation influenced experimentally implanted tumors and other biological tissues. The laser energy available to him was considerably weaker than he had originally expected, and it did not destroy the tumors.

Something unexpected happened instead. Mester and his colleagues observed that hair regrew more rapidly in shaved areas of laser-treated mice than in untreated controls. Their work on laser stimulation of hair growth was published in 1968.

That seemingly modest observation was scientifically provocative because a low dose of laser radiation had apparently stimulated biological activity rather than destroying tissue. Mester continued investigating, and his research soon expanded into wound healing and tissue repair.

In 1971, Mester and colleagues published experimental work demonstrating effects of laser radiation on wound healing. Other research followed involving ulcers and difficult-to-heal tissues.

What began as an investigation of whether laser energy could suppress malignant tissue helped uncover almost the opposite phenomenon. At sufficiently low intensities and appropriate parameters, laser light could stimulate biological processes. This became known as laser biostimulation, and Mester is now widely regarded as one of the founders of modern low-level laser therapy.

Terminology evolved as the science matured. Researchers used phrases including low-power laser therapy, low-intensity laser therapy, low-level laser therapy, cold laser therapy, soft laser therapy, and laser biostimulation.

The term photobiomodulation eventually became increasingly common because it describes the biological phenomenon rather than a particular machine. "Photo" refers to light, "bio" refers to living systems, and "modulation" refers to changing or regulating biological activity. Photobiomodulation therefore means, in simple terms, using light to alter biological activity. That terminology also recognizes something scientifically important: photobiomodulation is broader than laser technology alone. Certain light-emitting diode systems, or LEDs, can also produce photobiomodulatory effects when appropriate wavelengths, irradiance, dose, and treatment conditions are used.

This is where the discussion needs to be more sophisticated than simply declaring that lasers work and LEDs do not. LED photobiomodulation has legitimate scientific literature behind it. However, that does not mean that every inexpensive red-light panel, beauty mask, belt, tanning-style device, or Internet gadget produces the same biological effect as a medical laser used according to validated parameters.

The scientifically defensible distinction is between specific devices, wavelengths, energies, dosimetry, beam characteristics, protocols, regulatory indications, and supporting clinical evidence. Simply calling everything "red-light therapy" tells us remarkably little.

Ordinary light contains photons traveling in many directions and often includes many wavelengths. Laser light possesses unusual physical characteristics that make it especially useful when precision and controlled energy delivery are important.

Depending upon the system, laser light may be highly monochromatic, meaning that it occupies a relatively narrow wavelength range. It may be highly collimated, meaning that the beam travels with relatively little divergence, and coherent, meaning that the electromagnetic waves maintain defined relationships to one another.

Different wavelengths also interact differently with biological tissue. Some are absorbed readily at the surface, while others penetrate farther. Some interact strongly with water, while others interact with hemoglobin, melanin, mitochondrial chromophores, or other biological molecules.

This is why describing a therapeutic device merely as a "red light" tells us very little. Wavelength is important, but wavelength is only one variable in the treatment.

One of the most important developments in modern photobiomodulation research has been the investigation of mitochondria. These microscopic structures inside most human cells are commonly described as cellular power plants because they produce much of the ATP used to power cellular activity.

ATP stands for adenosine triphosphate. Every movement you make, every nerve impulse, every muscular contraction, every cellular repair process, and almost every complex biological activity depends directly or indirectly upon cellular energy.

Researchers have investigated how particular wavelengths of red and near-infrared light interact with mitochondrial components. One major hypothesis focuses on an enzyme called cytochrome c oxidase, or CCO, which occupies an important position in the mitochondrial respiratory chain.

Experimental research suggests that light absorption may alter mitochondrial signaling, influence nitric oxide biology, change membrane potential, affect reactive oxygen species signaling, and, under some circumstances, increase ATP production. Those changes can then influence downstream cellular processes.

Science continues to refine this mechanism. Cytochrome c oxidase is an important hypothesis, not a completed explanation for every photobiomodulation effect. More recent research has explored additional photoreceptors, ion channels, nitric oxide pathways, calcium signaling, transcription factors, water-related mechanisms, and other cellular responses. That is what responsible and accurate science looks like. A therapy does not become less interesting because researchers continue investigating the precise sequence of molecular events. It becomes more interesting.

A useful way to understand photobiomodulation is as a biological chain reaction. First comes the photon. A molecule capable of absorbing that wavelength interacts with the light, and that interaction produces an immediate cellular event. The initial event can then activate second-messenger systems involving nitric oxide, calcium changes, reactive oxygen species signaling, cyclic AMP, and other pathways. Those signals can influence transcription factors, which in turn can alter gene expression and protein synthesis. The result can eventually affect processes such as cellular survival, proliferation, migration, inflammation, tissue repair, and metabolism. This helps explain why a treatment involving a seemingly gentle beam of light can produce biological consequences that continue after the laser has been turned off.

The laser is not physically "healing" the tissue in the way glue repairs a broken object. The light supplies a stimulus, and the biology responds.

Drug therapy has taught everyone an intuitive principle: dose matters. Five milligrams is not fifty milligrams. Photobiomodulation has its own version of exactly the same concept. Researchers have repeatedly described biphasic dose responses. Too little energy may produce no meaningful biological response. An appropriate dose may stimulate the desired response, while more energy does not necessarily produce a better result. Excessive energy can sometimes diminish or even reverse the response researchers were attempting to produce.

This helps explain why photobiomodulation literature can appear inconsistent when someone merely counts positive and negative studies. Different investigations may use different wavelengths, powers, exposure times, device distances, tissues, energy densities, and treatment schedules. Some use lasers and others use LEDs. Some investigate acute conditions and others study chronic problems. Calling all of these experiments simply "laser therapy" is comparable to describing every pharmaceutical study as "pill therapy." The parameters matter.

Following Mester's work, low-level laser research expanded through Europe, the Soviet Union and Eastern Europe, Asia, Australia, South America, and eventually North America. Investigators explored possible effects involving wound healing, inflammation, edema, nerve injury, tendon and ligament tissue, musculoskeletal pain, arthritis, muscle recovery, bone repair, oral tissue, dermatologic conditions, and numerous other biological systems.

The literature did not produce uniform positive results, which should surprise no one familiar with medical research. Researchers instead learned that photobiomodulation is highly dependent upon protocol, wavelength, dose, target tissue, and other treatment variables. By the twenty-first century, systematic reviews and randomized controlled trials had accumulated in a number of areas. One particularly influential example appeared in The Lancet in 2009.

Chow and colleagues examined 16 randomized trials involving 820 patients with neck pain. Their meta-analysis found significant pain reduction associated with low-level laser therapy and reported benefits extending beyond the immediate treatment period in chronic neck pain.

This does not mean that every laser treats every pain disorder. It means that the technology had advanced far beyond a laboratory curiosity.

The American history of low-level laser therapy has one company appearing repeatedly: Erchonia. The company began conducting controlled clinical research on low-level laser therapy in the late 1990s and pursued an unusually evidence-focused strategy for the field.

Rather than merely selling a laser and relying upon generalized claims from the photobiomodulation literature, Erchonia conducted randomized, controlled clinical investigations designed to support specific FDA submissions. Its neck and shoulder pain research became historically important.

Erchonia reports that its initial study began in 1999 and was followed by a more restrictive study after the FDA requested additional evidence. The subsequent trial was randomized, double-blind, placebo-controlled, and multisite. The FDA record confirms that on January 17, 2002, the agency issued 510(k) clearance K012580 for the Erchonia PL2000/PL3000 device category for adjunctive use in pain therapy. That clearance is often described as the first FDA market clearance for a low-level laser in this therapeutic category.

The terminology matters. The FDA cleared the device through the 510(k) process. "FDA cleared" and "FDA approved" are not interchangeable regulatory terms because premarket approval, or PMA, is a different regulatory pathway generally associated with higher-risk devices. A scientifically responsible medical website should use the correct language. Erchonia received FDA clearance.

The neck and shoulder trial included patients suffering from chronic musculoskeletal pain. Among subjects completing the study, approximately 65 percent of the laser-treated group met the study's individual success criterion for pain improvement, compared with approximately 12 percent of the placebo group. The study also evaluated range of motion and related functional measurements. These results were important for more than one clinical application. They demonstrated that a low-level laser could withstand the scrutiny of a randomized, placebo-controlled investigation and support an American regulatory submission. For a field that had spent decades developing largely outside routine American medicine, that mattered enormously.

I began using Erchonia laser technology at the Liebell Clinic around 2004. At the time, low-level laser therapy was virtually unknown to the public in Hampton Roads. Our clinic became an early regional adopter of Erchonia technology, and laser therapy gradually became an important part of our approach to musculoskeletal pain, injury, and other carefully selected clinical applications.

That history matters to me because I did not discover cold laser therapy after red-light therapy became fashionable. We were working with clinical laser systems roughly two decades before inexpensive red-light panels began appearing everywhere on social media.

I have also experienced the technology personally. Following a serious fall that badly injured my right hand, laser therapy became an important part of my own recovery. That experience reinforced something I had already learned professionally: A treatment can look deceptively simple while the underlying biology is anything but simple.

A patient may simply see a beam of light. Behind that beam is more than a century of physics.

Erchonia continued performing clinical studies and pursuing additional regulatory clearances. Over time, Erchonia systems received FDA clearances involving applications including neck and shoulder pain, postsurgical pain, plantar fasciitis-related heel pain, chronic low-back pain, broader nociceptive musculoskeletal pain indications, and aesthetic uses.

In 2018, for example, the FDA cleared Erchonia's FX 635 device for chronic low-back pain of musculoskeletal origin. In 2019, Erchonia obtained an expanded indication involving temporary relief of chronic nociceptive musculoskeletal pain.

The larger point is not that an FDA clearance proves laser therapy treats everything. It does not. The important historical point is that low-level laser technology progressed from Mester's experimental observations in Hungary to controlled clinical trials and specific FDA-cleared applications in the United States. That is an extraordinary scientific journey.

This is where the language becomes almost comical. Some American insurance policies have continued to describe forms of low-level laser therapy as "investigational" or "experimental," terminology that deserves some historical context. Researchers have been studying the biological effects of low-level laser energy since the 1960s. Mester's early papers are old enough to have grandchildren. Major mechanistic papers examine mitochondrial signaling, randomized controlled trials exist, systematic reviews exist, and a major meta-analysis appeared in The Lancet.

Multiple medical laser devices have FDA clearances for defined indications, while scientific organizations, conferences, and journals have been devoted to photobiomodulation research. Calling the entire field "experimental" more than half a century after its discovery is therefore an extraordinarily broad use of the word. That does not mean every claim made about photobiomodulation has been proven. Many have not. Some applications remain preliminary, some studies conflict, dosimetry remains challenging, and some commercial devices are marketed far beyond their evidence. Those are legitimate scientific cautions. They are quite different from pretending that photobiomodulation itself is some newly invented medical curiosity. The technology has been studied for generations.

There is probably no single explanation. Medicine adopts new technologies unevenly, and reimbursement, training, specialty boundaries, clinical guidelines, familiarity, standardized protocols, and the quality of early research all influence adoption. Commercial exaggeration can also damage legitimate technologies because exaggerated claims invite appropriate skepticism. Photobiomodulation has another disadvantage: The treatment can look almost too simple.

A physician readily understands a pharmaceutical molecule manipulating a receptor, while a surgeon understands removing or repairing tissue. A treatment in which someone directs painless light toward tissue and the patient feels virtually nothing is less intuitively impressive.

Physics does not care whether a treatment looks impressive, and neither does cellular biology. The scientific questions concern which wavelength was used, how much power and energy were delivered, which device and protocol were employed, what tissue was treated, what outcome was measured, what control was used, and what the evidence actually demonstrated.

Those are the questions that matter.

The explosion of consumer red-light products has created a communications problem for serious photobiomodulation. Consumers can now purchase red-light masks, belts, LED mats, panels, handheld devices, beauty wands, and innumerable other products. Some may produce legitimate photobiomodulatory effects. Others may produce poorly characterized wavelengths, inadequate or inappropriate doses, or marketing claims that extend far beyond the evidence. It would therefore be scientifically inaccurate to say that all LED therapy is useless. It would be equally inaccurate to assume that every red-light product is equivalent to a medical laser or to every other PBM device.

Medical light technology should be evaluated according to actual wavelength, optical output, beam characteristics, irradiance, fluence, treatment geometry, exposure time, engineering, clinical protocol, safety testing, regulatory status, and evidence supporting the specific application.

Erchonia's importance lies substantially in that final distinction. The company repeatedly invested in device-specific clinical investigations and regulatory clearances. That is fundamentally different from selling a glowing device while borrowing generalized claims from unrelated photobiomodulation research.

One of the more surprising chapters in low-level laser history emerged from plastic surgery research. In 2002, Neira and colleagues published a study in Plastic and Reconstructive Surgery examining the effects of low-level laser energy on adipose tissue.

Electron microscopy demonstrated structural changes following laser irradiation, including the appearance of temporary openings in adipocyte membranes and release of intracellular lipid material. The researchers originally explored low-level laser energy in connection with liposuction.

Their findings raised a remarkable question. If laser exposure could cause adipocytes to release lipid material without surgically destroying the cells, could low-level laser energy potentially be used for non-invasive body contouring?

That question eventually led to Zerona.

Jackson and colleagues published a randomized, placebo-controlled study in Lasers in Surgery and Medicine in 2009 examining low-level laser therapy as a non-invasive approach to body contouring. The study evaluated circumference changes involving the waist, hips, and thighs.

Participants receiving active laser treatment demonstrated significantly greater combined circumference reduction than placebo-treated participants. The research established an entirely different application of low-level laser energy. The objective was not pain reduction, wound healing, or the destruction of fat cells through heat or cold. The objective was non-invasive circumference reduction through the interaction of low-level laser energy with adipose tissue. That work eventually contributed to an entirely new FDA device category.

In August 2010, the FDA granted the Erchonia ML Scanner, the technology that became widely associated with Zerona, a De Novo classification for non-invasive aesthetic body contouring. The device category was formally described as a fat-reducing low-level laser.

This regulatory history matters because low-level laser body contouring did not begin as an Internet wellness trend. It developed from laboratory research, microscopic investigation of adipocytes, controlled human studies, device engineering, and federal regulatory review. Subsequent generations of Zerona technology continued developing that platform.

Early Zerona research primarily involved red low-level laser wavelengths, particularly approximately 635 nm. Erchonia subsequently investigated violet laser energy around 405 nm. Different wavelengths interact differently with biological tissue. This is another reason it is inaccurate to speak about all "red light" or even all "laser light" as though wavelength were irrelevant. Erchonia eventually developed the Violet Zerona Z6. The FDA cleared the Violet Zerona Z6 OTC under 510(k) K231474 in July 2023 for non-invasive dermatological aesthetic treatment for the reduction of body circumference.

Then came the Zerona VZ8.

The Erchonia Zerona VZ8 represents the current generation of this technology used at the Liebell Clinic. The FDA granted the VZ8 510(k) clearance K243811 on January 10, 2025.

According to the FDA's 510(k) summary, the VZ8 is classified as a Class II fat-reducing low-level laser system intended for non-invasive aesthetic use. The FDA documentation describes low-level laser energy being used to disrupt adipocytes within the fat layer sufficiently to permit release of fat and lipid contents for non-invasive aesthetic use.

The VZ8 employs eight violet low-level laser emitters. Erchonia describes the treatment as creating temporary openings in adipocyte membranes, allowing lipid material to move outside the cells, after which normal physiological processes handle the released material.

The approach is fundamentally different from technologies designed to destroy adipocytes through heat, freezing, ultrasound, or surgical extraction. Zerona does not freeze tissue, heat it, suction it, or cut it. The patient does not require anesthesia, there is no surgical wound, and there is no expected recovery period from deliberate tissue destruction.

This is body contouring based upon a biological response to low-level laser energy.

This distinction deserves emphasis. Zerona VZ8 is FDA cleared for reduction of body circumference. That is body contouring, and it should not be confused with treatment for obesity or generalized weight loss.

The ideal candidate may already exercise, eat sensibly, and maintain a reasonably stable weight while remaining frustrated by localized areas that do not respond proportionally to overall fitness efforts. That is precisely why this technology occupies such an unusual niche.

For decades, people have correctly been told that conventional diet and exercise cannot reliably instruct the body to remove fat from one particular location first. Overall body weight can decrease while a stubborn abdomen, hip, thigh, back, arm, or other region remains disproportionately resistant.

Body contouring addresses a different problem from weight reduction.

Without its history, Zerona can sound almost unbelievable. Tell someone that violet laser light can influence fat cells and skepticism is a perfectly reasonable response. Now place Zerona inside the complete scientific story. Einstein described stimulated emission in 1917, Maiman constructed the first working laser in 1960, and Mester discovered biological stimulation from low-dose laser energy during the 1960s. Researchers then spent decades studying the effects of low-level light on living tissue.

Scientists investigated mitochondrial and cellular signaling mechanisms. Clinical researchers studied low-level lasers for pain and tissue applications. Erchonia began conducting controlled FDA-oriented trials in the late 1990s, and its first therapeutic low-level laser received FDA clearance in 2002. Researchers then demonstrated low-level laser-induced changes in adipose tissue. Controlled human trials investigated circumference reduction, the FDA established a regulatory category for fat-reducing low-level lasers, and successive generations of Zerona systems followed. The Zerona VZ8 received FDA clearance in 2025. 

Placed within that history, laser body contouring no longer sounds like something invented by a social-media marketer. It is the latest branch of a scientific story that began more than a century ago.

There is something remarkably satisfying about the history of laser therapy. Einstein was working on theoretical physics. Maiman built a device whose applications were not yet obvious. Mester was investigating cancer biology when he encountered an unexpected stimulatory effect.

Cellular researchers later investigated mitochondria and signaling pathways. Pain researchers conducted randomized trials. Plastic surgeons examined adipocytes under electron microscopes. Engineers refined wavelengths and delivery systems, while regulatory scientists evaluated increasingly sophisticated medical devices.

Eventually, a patient can lie beneath a Zerona VZ8 at the Liebell  Clinic in Virginia Beach while eight carefully engineered violet laser emitters deliver light derived from principles of physics first described more than a century ago.

That is not mystical, and it is certainly not "just shining a light on somebody."

It is applied photobiology.

Modern medicine understandably associates powerful treatment with powerful sensation. Injections hurt, surgery produces wounds, medications can create obvious systemic effects, heat feels hot, and cryotherapy feels cold.

Zerona produces none of those dramatic sensations, which can create a psychological contradiction. If nothing hurts, burns, freezes, vibrates, contracts, or shocks the tissue, people understandably wonder whether anything significant is occurring.

The history of photobiomodulation teaches a very different lesson. Biological potency does not require tissue destruction. A photon carries energy, and cells contain molecules capable of absorbing electromagnetic energy. That absorption can initiate biochemical signaling. The resulting biological effect depends upon wavelength, dose, tissue, timing, and the physiological system being targeted. A treatment does not become scientifically insignificant merely because the patient cannot feel the physics taking place.

Laser medicine has now existed long enough to possess its own substantial history, and that history did not progress in a perfectly straight line. Few scientific fields do. There were discoveries and mistakes, positive and negative studies, poor and improved protocols, skepticism and exaggeration, regulatory resistance and acceptance, evolving mechanisms, new wavelengths, and new applications. That complexity should increase respect for the science rather than diminish it.

Photobiomodulation continues to evolve. Researchers continue investigating its cellular mechanisms, and the quality of clinical evidence varies according to condition and protocol. Some proposed applications remain preliminary, while others have accumulated controlled clinical evidence and FDA-cleared devices. The responsible approach is neither to declare that light can cure everything nor to dismiss decades of research because a therapy looks unfamiliar. The responsible approach is to examine the physics, the biology, the device, the clinical trial, and the evidence.

That is what we have done at the Liebell Clinic since introducing Erchonia laser technology to our practice more than two decades ago. The equipment has changed dramatically, the science has advanced, and the applications have expanded. The underlying principle remains astonishingly elegant: Deliver the right light, at the right wavelength, in the right dose, to the right biological target, and living tissue can respond.

Einstein supplied the physics. Maiman supplied the laser. Mester uncovered its biological potential. Generations of researchers developed photobiomodulation, while Erchonia helped move low-level laser technology through controlled clinical research and American regulatory pathways.

Zerona took that science into adipose tissue and non-invasive body contouring. The Zerona VZ8 is the newest chapter.

The story is still being written.

The scientific study of low-level laser therapy and photobiomodulation extends across physics, cellular biology, pain research, tissue repair, postoperative applications, adipose tissue, body contouring, dermatology, veterinary medicine, and other fields. The references below provide examples of this extensive and continually developing scientific literature.

Einstein A. Zur Quantentheorie der Strahlung. Physikalische Zeitschrift. 1917;18:121-128.

Maiman TH. Stimulated optical radiation in ruby. Nature. 1960;187:493-494.

Mester E. A laser sugár alkalmazása a gyógyászatban [The use of the laser beam in therapy]. Orv Hetil. 1966;107(22):1012-1016.

Mester E, Szende B, Gärtner P. Die Wirkung der Laserstrahlen auf den Haarwuchs der Maus [Effect of laser rays on hair growth in mice]. Radiobiol Radiother (Berl). 1968;9(5):621-626. PMID: 5732466.

Mester E, Ludány G, Sellyei M, Szende B. On the biologic effect of laser rays. Bull Soc Int Chir. 1968;27(1):68-73. PMID: 5742748.

Mester E, Ludány G, Sellyei M, et al. Studies on the inhibiting and activating effects of laser beams. Langenbecks Arch Chir. 1968;322:1022-1027. doi:10.1007/BF02453990.

Mester E, Spiry T, Szende B, Tota JG. Effect of laser rays on wound healing. Am J Surg. 1971;122(4):532-535. doi:10.1016/0002-9610(71)90482-X.

Mester E, Jászsági-Nagy E. Biological effects of laser radiation. Radiobiol Radiother (Berl). 1971;12(3):377-385. PMID: 4946584.

Chung H, Dai T, Sharma SK, Huang YY, Carroll JD, Hamblin MR. The nuts and bolts of low-level laser (light) therapy. Ann Biomed Eng. 2012;40(2):516-533. doi:10.1007/s10439-011-0454-7.

Huang YY, Chen ACH, Carroll JD, Hamblin MR. Biphasic dose response in low level light therapy. Dose Response. 2009;7(4):358-383. doi:10.2203/dose-response.09-027.Hamblin.

Huang YY, Sharma SK, Carroll J, Hamblin MR. Biphasic dose response in low level light therapy: an update. Dose Response. 2011;9(4):602-618. doi:10.2203/dose-response.11-009.Hamblin.

Hamblin MR. Mechanisms and mitochondrial redox signaling in photobiomodulation. Photochem Photobiol. 2018;94(2):199-212. doi:10.1111/php.12864.

Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337-361. PMID: 28748217.

Chow RT, Johnson MI, Lopes-Martins RAB, Bjordal JM. Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials. Lancet. 2009;374(9705):1897-1908. doi:10.1016/S0140-6736(09)61522-1.

Neira R, Arroyave J, Ramirez H, et al. Fat liquefaction: effect of low-level laser energy on adipose tissue. Plast Reconstr Surg. 2002;110(3):912-922. doi:10.1097/00006534-200209010-00030.

Jackson RF, Dedo DD, Roche GC, Turok DI, Maloney RJ. Low-level laser therapy as a non-invasive approach for body contouring: a randomized, controlled study. Lasers Surg Med. 2009;41(10):799-809. doi:10.1002/lsm.20855.

US Food and Drug Administration. 510(k) K012580. Erchonia PL2000/PL3000. Decision date January 17, 2002.

US Food and Drug Administration. DEN090008/K082609. Erchonia ML Scanner. Decision date August 24, 2010.

US Food and Drug Administration. 510(k) K231474. Erchonia Violet Zerona Z6 OTC. Decision date July 21, 2023.

US Food and Drug Administration. 510(k) K243811. Erchonia Zerona VZ8. Decision date January 10, 2025.

Evaluation of Low-Level Laser Therapy at 635nm for the Treatment of Acute and Chronic Neck and Shoulder Pain: A Placebo-Controlled, Randomized Study
Laser in Surgery Medicine 2014, Volume 46, Number S25, March 2014. Ryan Maloney, Steven Shanks. Phoenix, AZ; Erchonia Corporation, McKinney, TX.

Low-Level Laser Therapy for the Treatment of Chronic Neck and Shoulder Pain
Funct Neurol Rehabil Ergon 2016;6(2):97-104. Gregory C. Roche; Daniel J. Murphy; Trevor S. Berry; Steven Shanks.

Effects of a Single Treatment with Two Non-Thermal Wavelengths on Chronic Neck and Shoulder Pain
Dove Press Journal, Medical Devices: Evidence and Research 2019:12 319-325. Robert G. Silverman, Albert Comey, Travis Sammons.

A Randomized, Double-Blind, Sham-Controlled Study Evaluating the Effectiveness of a Low-level Laser Device for Treating Lower Back Pain
eMedical Research, Volume 2, Article ID: 100005. Trevor S. Berry, Paul J. Quarneri, Gregory Roche, Travis M. Sammons.

Low-Level Laser Therapy for Treating Low Back Pain: 12-Month Follow-Up
Journal of Pain & Relief 2019, Volume 9, Issue 1. Trevor S. Berry, Paul J. Quarneri, Gregory Roche, Travis M. Sammons.

Low-Level Laser Therapy at 635 nm for Treatment of Chronic Plantar Fasciitis: A Placebo-Controlled, Randomized Study
Journal of Pain & Relief 2019, Volume 9, Issue 1. David M. Macias, Michael J. Coughlin, Kerry Zang, Faustin R. Stevens, James R. Jastifer, Jesse F. Doty.

Two Randomized, Double Blind, Placebo-Controlled Trials Evaluating the Efficacy of Red 635nm Low Level Laser for the Treatment of Low Back Pain
The Journal of Foot & Ankle Surgery. Trevor S. Berry, Paul J. Quarneri, Travis M. Sammons, Steve Shanks.

Efficacy of 635nm Red Low-Level Laser on Nociceptive Musculoskeletal Pain Compared to NSAIDS, Opioids, and Other Light Sources
Orthopedics and Rheumatology Open Access Journal, ISSN: 2471-6804. Jacob Januskewski, Chris Bromley, Cesar A Lara, Kirk Gair, Brandon Brock, Leonid Polishuk, Travis Sammons.

Low-Level Laser Therapy for the Treatment of Chronic Plantar Fasciitis: A Prospective Study
Foot & Ankle International, Volume 24, Number 4, April 2014. James R. Jastifer, MD; Fernanda Catena, MD; Jesse F. Doty, MD; Faustin Stevens, MD; Michael J. Coughlin, MD.

Assessing the Impact of High Photon Energy Wavelengths on the Treatment of Chronic Neck and Shoulder Pain
Evidence-Based Complementary and Alternative Medicine, Volume 2023, Article ID 6672019, 9 pages. Travis Sammons, Kirk Gair, Robert G. Silverman, Steve Shanks.

Low-Level Laser-Assisted Liposuction: A 2004 Clinical Study of its Effectiveness for Enhancing Ease of Liposuction Procedures and Facilitating the Recovery Process for Patients Undergoing Thigh, Hip, and Stomach Contouring
Robert F. Jackson, MD; Gregory Roche, DO; Kimberly J. Butterwick, MD; Douglas D. Dedo, MD; Kevin T. Slattery, MD.

Low-Level Laser-Assisted Liposuction: The Neira 4 L Technique
Clinics in Plastic Surgery. Rodrigo Neira, MD; Luiz Toledo, MD; Jose Arroyave, BSc, MSc, TEM, SEM; Efrain Solarte, Dr, Rer, Nat, MSc; Carolina Isaza, MO, MSc; Oscar Gutierrez, MD, MSc; William Criollo, BSc, MSc; Hugo Ramirez, VMD, MSc; Maria I. Gutierrez, MD, MSc, PhD; Clara L. Ortiz-Neira, MD.

Low Level Laser in Liposuction Results

Low-Level Laser Therapy Effectiveness for Reducing Pain After Breast Augmentation
American Journal of Cosmetic Surgery, Vol. 26, No. 3, 2009. Robert F. Jackson, MD; Gregory Roche, DO; Todd Mangione, DO.

A Double-Blind, Sham-Controlled Study Demonstrating the Effectiveness of Low-Level Laser Therapy Using a 532-nm Green Diode for Contouring the Waist, Hips, and Thighs
Study Abstract. David P. Suarez, DO; Gregory C. Roche, MD, FACS; Robert F. Jackson, MD, FACS.

Low-Level Laser Therapy as a Non-Invasive Approach for Body Contouring: A Randomized, Controlled Study
Lasers in Surgery Medicine 41:799-809 (2009). Robert F. Jackson, MD; Joug D. Dedo, MD; Greg C. Roche, MD; David I. Turok; Ryan J. Maloney.

The Use of Low Level Laser Therapy for Noninvasive Body Contouring
Aesthetic Medicine Art and Techniques. Robert F. Jackson, MD; Ryan J. Maloney.

Low-Level Laser Therapy for Reducing the Hip, Waist, and Upper Abdomen Circumference of Individuals with Obesity
Photomedicine and Laser Surgery, Volume 35, Number 3, 2017. Gregory C. Roche, DO; Steven Shanks; Robert F. Jackson, MD; Laura Jane Holsey, DO.

Dr. Neira Cosmetic Surgery 2001

A Double-Blind, Placebo-Controlled Randomized Trial Evaluating the Ability of Low-Level Laser Therapy to Improve the Appearance of Cellulite
Robert F. Jackson, MD; Gregory C. Roche, DO; Steven Shanks.

Erchonia Laser Therapy in the Treatment of Onychomycosis: A Preliminary Report on an Ongoing Clinical Trial
Podiatry Review, Vol. 71:2. Robert Sullivan; Deirdre O'Flynn, Clinical Director of Midleton Foot Clinic, Midleton, Ireland; Deirdre O'Flynn, Senior Associate, Midleton Foot Clinic.

A Retrospective Study of Non-thermal Laser Therapy for the Treatment of Toenail Onychomycosis
Journal of Clinical and Aesthetic Dermatology, May 2017. Kerry Zang, DPM; Robert Sullivan, BSc (Hons) Podiatry, MSc Pod Surgery, PgCAcup, FIChPA, MInstChP; Steven Shanks.

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