What Experts Say About Red Light Therapy

Red light therapy has moved from clinical research journals into mainstream health culture, propelled in large part by a handful of influential voices. Podcasters, biohackers, longevity researchers, and professional athletes have all weighed in — some with careful reference to the published science, others with enthusiasm that outpaces the evidence.

This article examines what prominent experts and public figures actually say about red light therapy, which devices they recommend, and — critically — how their claims hold up against the published literature. The goal is not to dismiss or endorse any individual, but to help you separate evidence-based recommendations from marketing, personal anecdote, and financial conflicts of interest.

Andrew Huberman

What He Says

Andrew Huberman, professor of neurobiology and ophthalmology at Stanford University School of Medicine, has discussed red light therapy extensively on the Huberman Lab Podcast. His coverage is notably more cautious and science-referenced than most influencer commentary.

Huberman’s key recommendations:

• Red light for skin and surface tissues at 630–660nm, citing the Wunsch & Matuschka (2014; PMID: 24286286) controlled trial showing improved skin complexion and collagen density
• Near-infrared (810–850nm) for deeper tissues and the importance of understanding the optical window in biological tissue
• Morning red light exposure as part of a broader light hygiene protocol, though he carefully distinguishes between photobiomodulation and circadian light exposure (which primarily involves melanopsin-mediated pathways at shorter wavelengths)
• Red light for testosterone and fertility — he has referenced the Ahn et al. (2013; PMID: 23681755) animal study showing increased testosterone in rats exposed to 670nm light, whilst noting the lack of robust human data
• Dosing matters — Huberman regularly emphasises the biphasic dose response (Huang et al., 2009; PMID: 19764898), warning that more light is not necessarily better

Devices He Has Mentioned

Huberman has mentioned Joovv panels on his podcast and has had a commercial relationship with the brand. He has also discussed general panel configurations and wavelengths without specific brand endorsements in some episodes.

Critical Assessment

Huberman is among the more responsible voices on red light therapy. He consistently references published studies, acknowledges limitations, and distinguishes between strong and weak evidence. His coverage of the biphasic dose response and mechanism of action (cytochrome c oxidase activation) aligns with the scientific consensus.

Where to be cautious: His discussion of red light for testosterone is based primarily on animal data. The Ahn et al. study used direct testicular irradiation in rats — the applicability to human males using a panel at waist height is uncertain. No large, randomised, controlled trial has confirmed this effect in humans. The commercial relationship with Joovv should also be considered when evaluating his device recommendations, though he has been relatively transparent about this.

Ben Greenfield

What He Says

Ben Greenfield, a self-described biohacker, fitness consultant, and author, is one of the most vocal advocates of red light therapy in the wellness space. His recommendations include:

• Full-body red light therapy panels used daily, often as part of a broader “biohacking” morning routine
• Red light for exercise recovery, citing research on photobiomodulation reducing delayed-onset muscle soreness (DOMS) and markers of muscle damage (Leal-Junior et al., 2015; PMID: 25803542)
• Intranasal red light devices for cognitive enhancement and brain health
• Red light saunas — combining infrared sauna heat with red/NIR LED panels, a concept he has promoted through his involvement with SaunaSpace
• Targeted red light for wound healing, skin health, and sleep optimisation

Devices He Has Promoted

Greenfield has commercially promoted Joovv (previously) and has more recently been associated with various red light and sauna brands. His website features affiliate links to multiple red light therapy devices and he has a history of financial relationships with product companies in this space.

Critical Assessment

Greenfield references genuine research but frequently extrapolates well beyond what the studies actually demonstrate. His recommendations often combine red light therapy with multiple other interventions (cold exposure, supplements, specific exercises), making it difficult to attribute any reported benefit to PBM specifically.

Where to be cautious: The “stack everything” approach — using red light alongside 10 other modalities — is not how clinical research works. Published PBM studies isolate the light intervention. When Greenfield reports personal benefits from a protocol combining red light, cold plunges, hydrogen water, and specific supplements, the red light component cannot be meaningfully evaluated. His frequent commercial relationships with device manufacturers create unavoidable conflicts of interest.

The exercise recovery evidence he cites is real — Leal-Junior et al. (2015; PMID: 25803542) and Ferraresi et al. (2012; PMID: 22985128) do support PBM for muscle recovery. But the specific protocols, devices, and “biohacking stacks” he promotes go well beyond what these studies tested.

Dave Asprey

What He Says

Dave Asprey, founder of Bulletproof and self-styled “father of biohacking,” was one of the earliest mainstream promoters of red light therapy. His claims include:

• Red light therapy as a core biohacking tool alongside his broader protocol of modified diets, supplements, and environmental optimisation
• Anti-ageing applications — Asprey positions red light as part of a longevity strategy, referencing mitochondrial function and cellular energy production
• TrueDark and red-light glasses for evening light management (distinct from PBM but often discussed in the same context)
• Targeted red light for brain function, citing transcranial PBM research

Devices He Has Promoted

Asprey has been associated with Joovv and has promoted various PBM devices through his media channels and Upgrade Labs biohacking centres, which feature red light therapy rooms.

Critical Assessment

Asprey’s claims about red light therapy are a mixture of legitimate science and significant overclaim. The basic mechanisms he describes — cytochrome c oxidase activation, increased ATP production, reduced oxidative stress — are well-established in the PBM literature (Karu, 2005; PMID: 16007521; de Freitas & Hamblin, 2016; PMID: 26745730). However, Asprey frequently presents preliminary or animal data as though it were established fact, and his claims about the degree of benefit are often unsubstantiated.

Where to be cautious: Asprey’s business model is built on selling products and experiences related to biohacking. His Upgrade Labs franchise features red light therapy as a premium service. This commercial incentive means his enthusiasm should be weighed against the evidence rather than taken at face value. The anti-ageing claims, while mechanistically plausible, are not supported by long-term human trials demonstrating that red light therapy extends lifespan or reverses biological ageing.

Dr Joseph Mercola

What He Says

Dr Joseph Mercola, an osteopathic physician and alternative medicine proponent, has written extensively about red light therapy on his website. His recommendations include:

• Near-infrared light for mitochondrial health, positioning PBM as a treatment for mitochondrial dysfunction underlying various chronic diseases
• Red light for skin cancer prevention — a claim that requires significant qualification
• Specific wavelength recommendations (660nm and 850nm as optimal), which aligns with the absorption peaks of cytochrome c oxidase
• Cautions about blue light exposure and the use of red/NIR light as a counterbalance

Critical Assessment

Mercola’s coverage of PBM mechanisms is often technically accurate at the cellular level — the science of CCO activation and ATP production is real. However, his broader health claims frequently extend far beyond what published research supports. Mercola has a well-documented history of promoting alternative health products and has received multiple warning letters from the US Food and Drug Administration (FDA) for making unsupported claims about other products.

Where to be cautious: Mercola’s claim that red light can help prevent skin cancer is misleading. Some in vitro studies have examined PBM’s effects on cancer cells, but the results are mixed and the clinical implications are unclear. Kara et al. (2018; PMID: 29556839) noted that PBM’s effects on cancer cells depend heavily on dose, wavelength, and cell type — some protocols stimulated cancer cell growth rather than inhibiting it. Using red light therapy with the expectation of cancer prevention is not evidence-based and could be dangerous if it leads someone to neglect proven screening and prevention measures.

Peter Attia

What He Says

Peter Attia, physician and longevity-focused podcaster (The Drive), takes a notably measured approach to red light therapy. His commentary has included:

• Acknowledgement of the basic science behind PBM, particularly the cytochrome c oxidase mechanism
• Caution about the quality of evidence — Attia has noted that while cell and animal studies are promising, the human clinical trial evidence is relatively thin for many claimed applications
• Specific interest in exercise recovery and potential musculoskeletal applications, where the evidence is somewhat stronger
• Scepticism about broad anti-ageing claims that lack rigorous clinical support

Critical Assessment

Attia represents the more cautious end of the expert spectrum. His approach — acknowledging the science whilst demanding better evidence before making strong recommendations — is arguably the most responsible position for a public-facing physician. He has not, to date, made red light therapy a central part of his public longevity protocols in the way that Huberman or Asprey have.

What this tells you: When a physician focused on longevity and performance does not strongly endorse a therapy, it may indicate that the evidence does not yet meet a high clinical bar. Attia’s measured stance should not be interpreted as dismissal — it reflects appropriate scientific caution.

Dr Rhonda Patrick

What She Says

Rhonda Patrick, biomedical scientist and host of the FoundMyFitness podcast, has discussed red light therapy in the context of:

• Mitochondrial health and ageing — she has explained the CCO mechanism clearly and accurately in her content
• Skin health and collagen production, referencing the Wunsch & Matuschka trial (PMID: 24286286)
• The importance of wavelength specificity — Patrick has discussed the difference between red (630–670nm) and near-infrared (810–850nm) wavelengths and their different tissue penetration profiles
• Sauna combined with light therapy — she has discussed infrared sauna use extensively, sometimes in the context of PBM

Critical Assessment

Patrick is a trained scientist and her explanations of PBM mechanisms tend to be accurate and well-referenced. She is generally more measured than Greenfield or Asprey in her claims, and she distinguishes between what is well-established and what is preliminary.

Where to be cautious: Patrick’s discussions sometimes conflate infrared sauna (which uses heat as the primary mechanism, with wavelengths far beyond the PBM range) with photobiomodulation. These are distinct therapies with different mechanisms, evidence bases, and applications. Infrared saunas operate at wavelengths in the thousands of nanometres and work through thermal effects, whilst PBM uses specific wavelengths (typically 630–1000nm) at non-thermal irradiances.

Bryan Johnson

What He Says

Bryan Johnson, tech entrepreneur behind the Blueprint longevity protocol, includes red light therapy as one component of his comprehensive anti-ageing programme. His approach involves:

• Full-body red/NIR panel sessions as part of a meticulously documented daily routine
• Measurement-driven assessment — Johnson’s protocol is notable for its emphasis on biomarker tracking, which in principle could help evaluate whether red light therapy is producing measurable effects
• Red light for skin quality, which he documents with regular dermatological assessments

Devices He Uses

Johnson has featured Joovv panels in his protocol documentation.

Critical Assessment

Johnson’s approach is interesting because of his commitment to objective measurement. However, his protocol involves dozens of simultaneous interventions — supplements, dietary restriction, exercise, sleep optimisation, hormone management, and more. Attributing any specific benefit to the red light therapy component is impossible without controlled withdrawal experiments.

Where to be cautious: Johnson’s is a sample size of one, with no control group and dozens of confounding variables. His results, whatever they may be, cannot be generalised. The inclusion of red light therapy in Blueprint tells you that Johnson believes it might help — it does not tell you that it does help, or by how much.

Celebrity Users

Several high-profile athletes and entertainers have publicly used red light therapy, bringing significant attention to the modality:

LeBron James

LeBron James has been photographed using a red light therapy device — reportedly for muscle recovery and injury prevention. Professional athletes using PBM for recovery is not unusual, and there is legitimate evidence supporting this application. Leal-Junior et al. (2015; PMID: 25803542) found that PBM applied before or after exercise reduced markers of muscle damage and improved recovery in a meta-analysis of 46 studies. Borsa et al. (2013; PMID: 23479077) confirmed benefits for exercise-induced skeletal muscle fatigue.

However, professional athletes have access to clinical-grade devices, physiotherapy teams, and treatment protocols that bear little resemblance to a consumer using a home panel. Extrapolating from an elite athlete’s recovery protocol to a home user’s experience is inadvisable.

Halle Berry

Halle Berry has publicly endorsed red light therapy for skin health, mentioning it as part of her skincare routine. The skin evidence is among the more established areas of PBM research — Wunsch & Matuschka (2014; PMID: 24286286) demonstrated measurable improvements in skin complexion and collagen density in a controlled trial. However, Berry’s endorsement is a personal testimonial, not a clinical data point. She also has access to professional dermatological treatments and devices that consumers do not.

Other Notable Users

Jessica Alba, Kourtney Kardashian, and various professional sports teams have been publicly associated with red light therapy. In each case, the same caveat applies: celebrity usage tells you about the therapy’s cultural popularity, not its clinical efficacy. These individuals are also frequently involved in commercial relationships with wellness brands, which must be factored into any assessment of their endorsements.

Separating Evidence from Endorsement

What the Research Actually Shows

The published PBM literature is substantial — over 5,000 papers on PubMed as of 2026. But quality varies enormously, and the gap between what the research demonstrates and what public figures claim is often wide.

Strong evidence (multiple RCTs or high-quality systematic reviews):

• Wound healing and tissue repair (Chung et al., 2012; PMID: 22220777)
• Oral mucositis in cancer patients (Zadik et al., 2019; PMID: 31139165)
• Musculoskeletal pain and inflammation (Bjordal et al., 2003; PMID: 14614489)
• Androgenetic alopecia — FDA-cleared devices exist (Lanzafame et al., 2014; PMID: 24078483)
• Exercise performance and recovery (Leal-Junior et al., 2015; PMID: 25803542)

Moderate evidence (some RCTs, promising but not definitive):

• Skin rejuvenation and collagen production (Wunsch & Matuschka, 2014; PMID: 24286286)
• Joint pain and arthritis symptom reduction (Bjordal et al., 2003; PMID: 14614489)
• Depression — transcranial PBM (Cassano et al., 2018; PMID: 29130996)

Preliminary evidence (pilot studies, case series, animal data):

• Cognitive enhancement in healthy individuals
• Testosterone production
• Fat reduction with consumer-grade devices
• Anti-ageing and longevity
• Alzheimer’s disease and dementia (Saltmarche et al., 2017; PMID: 28211344)

Red Flags in Expert Claims

When evaluating any public figure’s claims about red light therapy, watch for:

1. Citing animal studies as proof of human effects. Rat and mouse studies are useful for understanding mechanisms but do not reliably predict human outcomes. The history of medicine is littered with therapies that worked in rodents and failed in humans.

2. Conflating correlation with causation. “I started using red light therapy and my skin improved” is an anecdote, not evidence. Without a control group and blinding, any improvement could be due to placebo, natural variation, or the 15 other things the person changed simultaneously.

3. Financial conflicts of interest. If someone earns money from a red light therapy brand — through sponsorship, affiliate links, equity, or consulting fees — their recommendations are commercially motivated. This does not mean they are wrong, but it means you should seek independent verification.

4. Extrapolating from clinical to consumer devices. Many positive PBM studies used clinical-grade lasers or carefully calibrated LED arrays under controlled conditions. Consumer panels may deliver different irradiances, wavelengths, or beam profiles. A study’s positive result does not automatically transfer to every device on Amazon.

5. Ignoring negative or null results. The NEST stroke trials (Lampl et al., 2007; PMID: 17395058; Zivin et al., 2009; PMID: 19789381) are a cautionary tale — Phase II was promising, Phase III failed. Responsible experts discuss failures alongside successes.

How to Use Expert Opinions Wisely

Expert commentary can be a useful starting point for learning about red light therapy, but it should never be the endpoint. The most productive approach:

1. Listen to the expert, then read the study they cite. If they do not cite a study, treat the claim with extra scepticism.
2. Check the study design. A randomised controlled trial in humans is more relevant than a cell culture experiment or animal model.
3. Consider the expert’s incentives. Do they sell devices, run a biohacking business, or have sponsorship deals? Factor this into your assessment.
4. Look for independent replication. One positive study is interesting. Three independent groups finding the same result is convincing.
5. Distinguish between “plausible” and “proven.” Many PBM applications are biologically plausible based on mechanism. That is not the same as clinically proven through rigorous trials.

Summary

The expert landscape around red light therapy ranges from cautious, evidence-grounded commentary (Huberman, Attia, Patrick) to enthusiastic overclaim (Asprey, Greenfield). Celebrity endorsements from figures like LeBron James and Halle Berry add cultural visibility but no scientific weight.

The core science of photobiomodulation is real — cytochrome c oxidase activation, ATP production enhancement, and modulation of reactive oxygen species are established mechanisms with decades of research behind them (Hamblin, 2017; PMID: 28748217). But the gap between established mechanism and proven clinical application remains wide for many popular claims.

The most useful expert voices are those who reference specific studies, acknowledge the limitations of the evidence, distinguish between strong and weak data, and disclose their financial relationships with device manufacturers. If an expert tells you red light therapy is a miracle that fixes everything, they are selling you something. If they tell you it is well-supported for certain applications, promising for others, and unproven for many more — they are probably telling you the truth.

References

1. Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomed Laser Surg. 2014;32(2):93-100. PMID: 24286286
2. Huang YY, et al. Biphasic dose response in low level light therapy. Dose Response. 2009;7(4):358-383. PMID: 19764898
3. Ahn JC, et al. Effect of low-level laser therapy on the Leydig cells of the testis in streptozotocin-induced diabetic rats. Photomed Laser Surg. 2013;31(7):327-332. PMID: 23681755
4. Karu TI. Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR-A radiation. IUBMB Life. 2005;57(8):607-615. PMID: 16007521
5. de Freitas LF, Hamblin MR. Proposed mechanisms of photobiomodulation or low-level light therapy. IEEE J Sel Top Quantum Electron. 2016;22(3):7000417. PMID: 26745730
6. Leal-Junior EC, et al. Effect of phototherapy on exercise performance and markers of exercise recovery: a systematic review with meta-analysis. Lasers Med Sci. 2015;30(2):925-939. PMID: 25803542
7. Ferraresi C, et al. Low-level laser (light) therapy (LLLT) on muscle tissue: performance, fatigue and repair benefited by the power of light. Photonics Lasers Med. 2012;1(4):267-286. PMID: 22985128
8. Borsa PA, et al. Therapeutic effects of low-level laser therapy (LLLT) on exercise-induced skeletal muscle fatigue. Clin J Sport Med. 2013;23(3):238-239. PMID: 23479077
9. Chung H, et al. The nuts and bolts of low-level laser (light) therapy. Ann Biomed Eng. 2012;40(2):516-533. PMID: 22220777
10. Zadik Y, et al. Systematic review of photobiomodulation for the management of oral mucositis in cancer patients and clinical practice guidelines. Support Care Cancer. 2019;27(10):3969-3983. PMID: 31139165
11. Bjordal JM, et al. A systematic review of low level laser therapy with location-specific doses for pain from chronic joint disorders. Aust J Physiother. 2003;49(2):107-116. PMID: 14614489
12. Lanzafame RJ, et al. The growth of human scalp hair mediated by visible red light laser and LED sources in males. Lasers Surg Med. 2014;46(4):373-377. PMID: 24078483
13. Cassano P, et al. Transcranial photobiomodulation for the treatment of major depressive disorder: the ELATED-2 pilot trial. Photomed Laser Surg. 2018;36(12):634-646. PMID: 29130996
14. Saltmarche AE, et al. Significant improvement in cognition in patients with dementia: transcranial plus intranasal photobiomodulation. Alzheimers Dement (N Y). 2017;3(3):348-353. PMID: 28211344
15. Lampl Y, et al. Infrared laser therapy for ischemic stroke: results of the NeuroThera Effectiveness and Safety Trial-1 (NEST-1). Stroke. 2007;38(6):1843-1849. PMID: 17395058
16. Zivin JA, et al. Effectiveness and safety of transcranial laser therapy for acute ischemic stroke. Stroke. 2009;40(4):1359-1364. PMID: 19789381
17. Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337-361. PMID: 28748217
18. Kara C, et al. Low level laser therapy induces increased viability and proliferation in isolated cancer cells. Headache. 2018;58(3):446-453. PMID: 29556839