How does low-level laser therapy (photobiomodulation) work?
You might be surprised to learn that your hair, just like you, can benefit from a good workout. But since your hair can’t lift weights or run on a treadmill, you use a low-level laser therapy (LLLT) device like a laser cap or comb. Taking the exercise analogy one step further, here’s how the process works:
- Stimulation of Mitochondria in Hair Bulge Stem Cells: Inside each of your hair follicles, there’s a place called the bulge that houses the stem cells responsible for hair regeneration. If you picture these stem cells as the bodybuilders in the gym of your hair, the mitochondria within these stem cells are the muscles they need to exercise. LLLT is the unique gym membership that gives these mitochondria the workout they need to become more active.
- Activation of Cytochrome c Oxidase (CCO): In this gym, your personal trainer is an enzyme called Cytochrome c Oxidase (CCO), located inside the mitochondria. This trainer’s job is to guide the production of Adenosine Triphosphate (ATP). It’s like the energy drink of your cells, providing the power needed for your hair’s activities. When you use your LLLT device, your personal trainer gets supercharged, becoming even better at helping your hair produce more ATP.
- Mitochondrial Respiration: This is your hair’s workout routine, taking in nutrients and oxygen and converting them into ATP. With the supercharged personal trainer, CCO, this routine becomes even more effective, resulting in more ATP. It’s like you being able to lift heavier weights and get stronger, faster.
- Production of Reactive Oxygen Species (ROS): Picture ROS as the sweat produced during an intense workout. Too much can cause dehydration, but just the right amount is a sign of a good, beneficial session. Similarly, the right amount of ROS, produced during your hair’s LLLT-enhanced workout, is beneficial and contributes to the overall process.
- Activation of Cellular Proliferation, Migration, and Oxygenation: The ATP and ROS produced in this workout motivate your hair cells to grow, move around, and breathe better. All these processes are crucial for effective LLLT treatment, just as they are essential when you’re doing a full body workout.
The origins and history of LLLT and photobiomodulation.
1903: Physician Niels Finsen, who developed the first artificial light source for heliotherapy (the application of sunlight to promote healing), opened the Institute of Heliotherapy and became known for his treatment of skeletal tuberculosis.
1957: American physicists Charles Hard Townes and Arthur Leonard Schawlow for Bell Labs, and Gordon Gould for TRG (Technical Research Group) conducted research that led to the discovery of light amplification by stimulated emission of radiation (LASER) technology.
1961: Leon Goldman researched the effect of laser beams on skin for the removal of tattoos and serendipitously discovered “bloodless surgery,” later becoming known as the father of laser medicine in 1979.
1965: Hungarian physician Endre Mester discovered the biostimulation effect of light by testing low-level 694nm ruby laser on shaved mice. He observed that the mice treated with the LLLT grew hair back faster than those not treated with LLLT.
2007: The U.S. Food and Drug Administration (FDA) cleared the first low-level laser therapy (LLLT) device, the HairMax LaserComb, for use in male patients suffering from pattern hair loss (PHL). This clearance was obtained through the 510(k) process.
2008: Russian scientist, Tiina Karu, identified cytochrome c oxidase in the mitochondrial respiratory chain as a primary chromophore. She introduced the concept of “retrograde mitochondrial signaling” to explain how a single, brief exposure to light could have effects that last for hours, days, or even weeks.
2020: 32 home-use LLLT devices have been cleared as of January 2020 via the 510(k) process by the FDA.
Benefits of LLLT
Low-level laser therapy is non-invasive, and science backed. Here’s why a LLLT device might be a good fit for you:
- It’s safe: A significant advantage of low-level laser therapy is its safety. The most common devices (across all uses of LLLT, not just for hair regrowth) have wavelengths in the range 500–1,100 nm (the so-called optical window of tissue). Lasers in these wavelengths are not strong enough to damage cells. Also, Class 3R lasers are specifically limited to a device power of 5 mW to prevent any potential eye hazards during brief exposures – though it’s best not to look at the lasers directly, in any case. If you’re using an LLLT device that adheres to the cleared FDA safety regulations, you can feel confident in the safety of your device.
- Minimal side effects: Like any therapy, using an LLLT device does have potential risks and side effects, albeit minimal. These can include skin irritation and redness in the area(s) of application but are rarely reported.
- Complementary to other treatments: LLLT devices can be used alongside all other hair loss prevention modalities. Whether you’re already using topical treatments, getting PRP injections, taking supplements or finasteride, or considering a hair transplant surgery, LLLT can seamlessly integrate into your existing routine, augmenting the impact of these treatments and potentially accelerating results.
- Works for almost everyone: Hair loss can affect all of us! LLLT is a near-universal solution suitable for patients experiencing hair loss. Other options, like finasteride, have restrictions for use by people who are pregnant or who may become pregnant, but LLLT does not have such limitations. This makes it an accessible and effective option for a wider range of patients.
- Scientifically Backed: LLLT isn’t just a trend — it’s a treatment approach backed by a wealth of scientific research. Numerous clinical studies have demonstrated its effectiveness in promoting hair growth and slowing hair loss. When you choose LLLT, you’re choosing a method grounded in scientific evidence, giving you confidence in its potential to help you meet your hair restoration goals.
LLLT is a powerful tool in the fight against hair loss. With its adaptability, safety, inclusivity, and strong scientific backing, it offers an approach that is as comprehensive as it is compelling. As you continue your research and consider your options, we believe that LLLT stands out as a valuable solution worth considering.
Are low-level laser therapy (LLLT) devices FDA-approved?
The FDA doesn’t actually “approve” medical devices in the same way they approve drugs. Instead, device manufacturers must apply for premarket approval (PMA) or 510(k) clearance, depending on the classification of the device.
The first LLLT device for hair loss, the HairMax LaserComb was granted 510(k) clearance in 2007 based on the fact that it is substantially equivalent to predicate devices already on the market. The FDA provides public access to a database of all 510(k) applications and clearances, which include information on the device, its intended use, and data to demonstrate its safety and effectiveness. FDA clearance indicates that the device can be legally marketed in the United States.
So, while LLLT devices have been cleared by the FDA for safety and effectiveness, it’s essential to note that “FDA cleared” is different from “FDA approved.” FDA approval is a significant designation that typically applies to prescription drugs, indicating that they have undergone extensive testing to determine their safety and effectiveness. FDA clearance, which is what some LLLT devices have received, indicates that a device is considered safe for use for a particular indication, most often because it is “substantially equivalent” to another legally marketed device.
Does LLLT have clinical research to back up its claims?
Yes! Studies of LLLT are plentiful:
- A study in 2009 reviewed 1200 papers about low-level laser therapy across medical specialties and found 85 positive and 35 negative double-blind studies.
- A review in 2017 analyzed 13 clinical trials of LLLT for hair regrowth specifically: ten out of 11 trials showed statistically significant improvement in pattern hair loss (PHL) with LLLT treatment compared to their baseline or controls. The other two trials indicated notable improvement through hair count or photos but didn’t do a statistical analysis.
- A meta-analysis in 2021 reviewed the 32 commercially-available, home-use, low-level light & laser therapy devices specifically design to treat pattern hair loss and found that LLLT improves hair density on the scalp. The results across studies varied widely, but the metanalysis found no statistically significant difference between sexes or device types in their ability to increase hair density, suggesting that LLLT devices are generally effective across the board. The authors do recommend future studies that compare the devices to each other in head-to-head studies, as well as the study of LLLT combined with other hair loss modalities.
Will low-level laser therapy work for me?
LLLT has been shown in some studies to promote hair growth in people with androgenetic alopecia, but the success of the treatment depends on many factors, including the cause of your hair loss, how much you’ve lost, and how long it’s been gone, plus individual health factors, and consistency in using the device as instructed.
It’s important to note that while some patients may experience new hair growth, others may not see a significant change. LLLT is more effective at slowing down hair loss than it is at regrowing already lost hair. If you have the same number of hairs at the end of the year as at the beginning, that’s a win! In this situation, the LLLT has slowed the progression of hair loss so well that it appears to have stopped. Continued use of the LLLT device is key.
How often should I use my LLLT device?
Every LLLT device is different, so it’s essential to follow the recommended usage guidelines provided by the manufacturer. Depending on the number and position of the laser diodes and if the light is static or intermittent will determine how frequently you should use your device and for what length of time per sitting.
You May Also Be Interested In
- Darwin, E., Heyes, A., Hirt, P.A. et al. Low-level laser therapy for the treatment of androgenic alopecia: a review. Lasers Med Sci 33, 425–434 (2018). https://doi.org/10.1007/s10103-017-2385-5
- Hamblin MR. Photobiomodulation or low-level laser therapy. J Biophotonics. 2016 Dec;9(11-12):1122-1124. doi: 10.1002/jbio.201670113. PMID: 27973730; PMCID: PMC5215795.
- Hamblin MR. Photobiomodulation for the management of alopecia: mechanisms of action, patient selection and perspectives. Clin Cosmet Investig Dermatol. 2019 Sep 6;12:669-678. doi: 10.2147/CCID.S184979. PMID: 31686888; PMCID: PMC6737896.
- Huang YY, Chen AC, Carroll JD, Hamblin MR. Biphasic dose response in low level light therapy. Dose Response. 2009 Sep 1;7(4):358-83. doi: 10.2203/dose-response.09-027.Hamblin. PMID: 20011653; PMCID: PMC2790317.
- International Society of Hair Restoration Surgery. (n.d.). Low Level Laser Therapy (LLLT) aka Photobiomodulation (PBM) and the Effectiveness of Current Devices for Treating Hair Loss. https://ishrs.org/patients/treatments-for-hair-loss/medications/photobiomodulation-pbm-lllt/
- Lueangarun S, Visutjindaporn P, Parcharoen Y, Jamparuang P, Tempark T. A Systematic Review and Meta-analysis of Randomized Controlled Trials of United States Food and Drug Administration-Approved, Home-use, Low-Level Light/Laser Therapy Devices for Pattern Hair Loss: Device Design and Technology. J Clin Aesthet Dermatol. 2021 Nov;14(11):E64-E75. PMID: 34980962; PMCID: PMC8675345.
- Mester, E., Ludany, G., Selyei, M., Szende, B., & Total, G. J. (1968). The stimulating effect of low power laser rays on biological systems. United Kingdom.
- Tunér, J., & Hode, L. (1998). It’s all in the parameters: A critical analysis of some well-known negative studies on low-level laser therapy. Journal of Clinical Laser Medicine & Surgery, 16(5), 245-248. http://doi.org/10.1089/clm.1998.16.245