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Presentation

Photobiomodulation and Low-Level Light Therapy for Hair Growth

Description

The speaker explains photobiomodulation, or low-level light therapy, as a potentially useful treatment for hair growth, especially because hair follicles are actively growing structures and mitochondria-rich tissues may respond well. He traces the therapy’s history from early observations in the 1960s that laser-irradiated mice grew more hair, to later FDA-cleared devices and clinical studies, including the first major 2009 trial for male pattern hair loss that showed increased terminal hair counts with a red light device, though not all subjective assessments improved. He notes that most later trials have been positive, with some negative or underpowered studies, and suggests benefits may be roughly comparable to topical minoxidil. Advantages include low long-term cost, no disposables, few side effects, and the sense that patients are actively doing something; drawbacks are the time commitment, inconvenience, and likely regression if treatment stops. Mechanistically, he describes red and near-infrared wavelengths affecting cytochrome c oxidase in mitochondria by releasing nitric oxide, thereby increasing respiration and ATP, and also discusses a separate 980 nm pathway that may stimulate calcium signaling via water vibration in channels. He emphasizes that wavelength choice, dose, and hair characteristics affect effectiveness, that too much light can be inhibitory, and that better dose-response studies are still needed. He concludes that the therapy can be combined with other treatments and is unlikely to interfere with medications, but that many practical and scientific unknowns remain.

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Conclusions

Photobiomodulation appears to be a real and biologically plausible hair-loss treatment rather than a placebo, especially for actively growing hair follicles.
The clinical evidence suggests red and near-infrared light can increase terminal hair counts in androgenetic alopecia, although not every study shows a clear global clinical benefit.
Its effectiveness may be roughly comparable to topical minoxidil for some patients, with the main advantages being low ongoing cost and minimal side effects.
The treatment is likely dose dependent, with too little light being ineffective and too much light potentially suppressing or inhibiting the response.
Mitochondrial cytochrome c oxidase is a leading proposed target, with light thought to displace nitric oxide and improve respiration and ATP production.
A second proposed mechanism at around 980 nm may work through temperature-sensitive calcium channels and could be especially efficient, but hair-specific evidence is still limited.
Device wavelength, dosage, and hair characteristics likely matter, but the field still lacks robust comparative trials, action spectra, and human dose-response data.
Photobiomodulation may be useful as an adjunct to other hair-loss treatments, but combining it with minoxidil has not clearly shown added benefit in at least one trial.
The overall conclusion is optimistic but cautious: the therapy may help some patients, yet the best parameters and ideal place in practice remain uncertain.
Light-based hair growth is possible, but it is easier to use light to remove hair than to grow it.

Leavitt M et al. HairMax LaserComb laser phototherapy device in the treatment of male androgenetic alopecia: a randomized, double-blind, sham device-controlled, multicentre trial. Clin Drug Investig. 2009;29:283-292.#10.2165/00044011-200929050-00001
Ferrara F et al. Efficacy of minoxidil combined with photobiomodulation for the treatment of male androgenetic alopecia: a double-blind half-head controlled trial. Lasers Surg Med. 2021;53(9):1201-1207.#10.1002/lsm.23411
Wang H, Huang L, Wang Y, Lyu P, Hamblin MR. Photobiomodulation of human adipose-derived stem cells using 810 and 980 nm lasers. Biochemical and Biophysical Acta. 2017.