https://pmc.ncbi.nlm.nih.gov/articles/PMC11991943/

https://pmc.ncbi.nlm.nih.gov/articles/PMC3926176/

https://www.liebertpub.com/doi/10.1089/photob.2019.4740

https://pubmed.ncbi.nlm.nih.gov/20662037/

https://pubmed.ncbi.nlm.nih.gov/24610987/

https://www.webmd.com/sleep-disorders/insomnia-symptoms-and-causes

https://www.webmd.com/sleep-disorders/sleep-apnea/sleep-apnea

https://pubmed.ncbi.nlm.nih.gov/21075236/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3499892/ 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6506010/

https://pubmed.ncbi.nlm.nih.gov/25417170/

Effect of low-level laser therapy on blood flow and oxygen- hemoglobin saturation of the foot skin in healthy subjects: a pilot study
https://pubmed.ncbi.nlm.nih.gov-/24155546/

Study on mechanism of release oxygen by photo-excited hemoglobin in low-level laser therapy
https://pubmed.ncbi.nlm.nih.gov/29067617/ https://www.ncbi.nlm.nih.gov/pubmed/27416624

Limb Blood Flow After Class 4 Laser Therapy
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3418129/

Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126803/

Effect of low-level laser therapy on mesenchymal stem cell proliferation: a systematic review
https://pubmed.ncbi.nlm.nih.gov/25764448/

Effects of Low-Level Laser Therapy Applied Before Treadmill Training on Recovery of Injured Skeletal Muscle in Wistar Rats
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4860654/

Effect of 830 nm low-level laser therapy in exercise-induced skeletal muscle fatigue in humans
https://pubmed.ncbi.nlm.nih.gov/18649044/

The transcription factor NF-kB is activated through exposure to free radicals generated by red and near-infrared light, which promotes a very low level inflammatory response. This then engages a mechanism called the NRF2 pathway and the Antioxidant Response Element (A.R.E.) – our internal cellular antioxidant defense system – which helps put out the fire by eliminating the inflammation and free radicals. In short, in much the same way that exercise builds your muscles stronger by temporarily stressing them, light does the same thing to our internal anti-oxidant and anti-inflammatory defense system.

Red light therapy might offer several benefits that indirectly support hormonal health, such as improved sleep [16] (enhances recovery and hormonal balance), reduced inflammation [17] (chronic inflammation suppresses testosterone), and more efficient mitochondria [18,19], which support vitality and resilience.

[1]         G. Corona, M. Maggi, The role of testosterone in male sexual function, Rev Endocr Metab Disord 23 (2022) 1159–1172. https://doi.org/10.1007/s11154-022-09748-3.

[2]         G. Chodick, S. Epstein, V. Shalev, Secular trends in testosterone- findings from a large state-mandate care provider, Reprod Biol Endocrinol 18 (2020) 19. https://doi.org/10.1186/s12958-020-00575-2.

[3]         T.G. Travison, A.B. Araujo, A.B. O’Donnell, V. Kupelian, J.B. McKinlay, A Population-Level Decline in Serum Testosterone Levels in American Men, The Journal of Clinical Endocrinology & Metabolism 92 (2007) 196–202. https://doi.org/10.1210/jc.2006-1375.

[4]         H. Cheng, X. Zhang, Y. Li, D. Cao, C. Luo, Q. Zhang, S. Zhang, Y. Jiao, Age-related testosterone decline: mechanisms and intervention strategies, Reprod Biol Endocrinol 22 (2024) 144. https://doi.org/10.1186/s12958-024-01316-5.

[5]         P.M. Luther, N.J. Spillers, N.C. Talbot, E.S. Sinnathamby, D. Ellison, R.A. Kelkar, S. Ahmadzadeh, S. Shekoohi, A.D. Kaye, Testosterone replacement therapy: clinical considerations, Expert Opinion on Pharmacotherapy 25 (2024) 25–35. https://doi.org/10.1080/14656566.2024.2306832.

[6]         G.E. Glass, Photobiomodulation: The Clinical Applications of Low-Level Light Therapy, Aesthetic Surgery Journal 41 (2021) 723–738. https://doi.org/10.1093/asj/sjab025.

[7]         V. Couturaud, M. Le Fur, M. Pelletier, F. Granotier, Reverse skin aging signs by red light photobiomodulation, Skin Research and Technology 29 (2023) e13391. https://doi.org/10.1111/srt.13391.

[8]         T. Lei, Y. Yang, W.-X. Yang, Luteinizing Hormone Regulates Testosterone Production, Leydig Cell Proliferation, Differentiation, and Circadian Rhythm During Spermatogenesis, IJMS 26 (2025) 3548. https://doi.org/10.3390/ijms26083548.

[9]         O.O. Oduwole, I.T. Huhtaniemi, M. Misrahi, The Roles of Luteinizing Hormone, Follicle-Stimulating Hormone and Testosterone in Spermatogenesis and Folliculogenesis Revisited, IJMS 22 (2021) 12735. https://doi.org/10.3390/ijms222312735.

[10]       H. Taheri, H.R. Mosleh, S. Jahanbaz, A. Aliaghaei, F. Tahmasebinia, M. Abedi, S. Abbasi, H.-A. Abbaszadeh, Therapeutic Effects of Low-Level Laser Therapy on Rat Spinal Cord Injury: Analysis of Inflammatory Markers and Testicular Function, J Lasers Med Sci 16 (2025) e6. https://doi.org/10.34172/jlms.2025.06.

[11]       F. Aghajanpour, H.-A. Abbaszadeh, H. Nazarian, A. Afshar, R. Soltani, H. Bana Derakhshan, F. Fadaei Fathabadi, M. Norouzian, Photobiomodulation Improves Histological Parameters of Testis and Spermatogenesis in Adult Mice Exposed to Scrotal Hyperthermia in the Prepubertal Phase, J Lasers Med Sci 15 (2024) e49. https://doi.org/10.34172/jlms.2024.49.

[12]       F. Aqajanpor, B.J. Kondori, M.H. Asadi, M. Raei, M.G. Nezhadian, H. Bahadoran, Photobiomodulation is more effective than long-term scrotal hyperthermia in improving testis tissue and spermatogenesis in mice with busulfan-induced azoospermia, Clin Exp Reprod Med 52 (2025) 283–294. https://doi.org/10.5653/cerm.2024.07430.

[13]       M.B.R. Alves, R.P. De Arruda, L. Batissaco, S.A. Florez-Rodriguez, B.M.M. De Oliveira, M.A. Torres, G.M. Ravagnani, R. Lançoni, T.G. De Almeida, V.M. Storillo, V.S. Vellone, C.R. Franci, H.E. Thomé, C.L. Canella, A.F.C. De Andrade, E.C.C. Celeghini, Low-level laser therapy to recovery testicular degeneration in rams: effects on seminal characteristics, scrotal temperature, plasma testosterone concentration, and testes histopathology, Lasers Med Sci 31 (2016) 695–704. https://doi.org/10.1007/s10103-016-1911-1.

[14]       L. Bossini, C. Caterini, D. Koukouna, I. Casolaro, M. Roggi, S. Di Volo, F. Fargnoli, R. Ponchietti, J. Benbow, A. Fagiolini, [Light therapy as a treatment for sexual dysfunctions–beyond a pilot study], Psychiatr Pol 47 (2013) 1113–1122.

[15]       A.M. Zagatto, Y.M. Dutra, F.S. Lira, B.M. Antunes, J.B. Faustini, E.D.S. Malta, V.H.F. Lopes, R.A.B. De Poli, G.M.P. Brisola, G.V. Dos Santos, F.M. Rodrigues, C. Ferraresi, Full Body Photobiomodulation Therapy to Induce Faster Muscle Recovery in Water Polo Athletes: Preliminary Results, Photobiomodulation, Photomedicine, and Laser Surgery 38 (2020) 766–772. https://doi.org/10.1089/photob.2020.4803.

[16]       R. Pan, G. Zhang, F. Deng, W. Lin, J. Pan, Effects of red light on sleep and mood in healthy subjects and individuals with insomnia disorder, Front. Psychiatry 14 (2023) 1200350. https://doi.org/10.3389/fpsyt.2023.1200350.

[17]       M.R. Hamblin, Mechanisms and applications of the anti-inflammatory effects of photobiomodulation, AIMS Biophysics 4 (2017) 337–361. https://doi.org/10.3934/biophy.2017.3.337.

[18]       M.B. Powner, G. Jeffery, Light stimulation of mitochondria reduces blood glucose levels, Journal of Biophotonics 17 (2024) e202300521. https://doi.org/10.1002/jbio.202300521.

[19]       C. Ferraresi, B. Kaippert, P. Avci, Y. Huang, M.V.P. De Sousa, V.S. Bagnato, N.A. Parizotto, M.R. Hamblin, Low‐level Laser (Light) Therapy Increases Mitochondrial Membrane Potential and ATP Synthesis in C2C12 Myotubes with a Peak Response at 3–6 h, Photochem & Photobiology 91 (2015) 411–416. https://doi.org/10.1111/php.12397.

[20]       F. Gonzalez-Lima, A. Auchter, Protection against neurodegeneration with low-dose methylene blue and near-infrared light, Front. Cell. Neurosci. 9 (2015). https://doi.org/10.3389/fncel.2015.00179.

[21]       R. Meynaghizadeh-Zargar, S. Sadigh-Eteghad, G. Mohaddes, F. Salehpour, S.H. Rasta, Effects of transcranial photobiomodulation and methylene blue on biochemical and behavioral profiles in mice stress model, Lasers Med Sci 35 (2020) 573–584. https://doi.org/10.1007/s10103-019-02851-z.

[22]       J. Hepburn, S. Williams-Lockhart, R.J. Bensadoun, R. Hanna, A Novel Approach of Combining Methylene Blue Photodynamic Inactivation, Photobiomodulation and Oral Ingested Methylene Blue in COVID-19 Management: A Pilot Clinical Study with 12-Month Follow-Up, Antioxidants 11 (2022) 2211. https://doi.org/10.3390/antiox11112211.

Red and near-infrared light help promote the production of internal antioxidants by your cells, which prevents oxidative stress and damage to the muscle tissue (when light is applied before exercise).

Red and near-infrared light help reduce inflammation that will lead to cellular damage (and fatigue) in the muscle tissue as well.

Protect damaged muscles from secondary damage from further exercise.

Pre-conditioning: By using the light prior to exercise, it creates a “pre-conditioning” effect where the muscle cells suffer less damage from the exercise, as well as display higher strength/stamina in subsequent exercise following the initial bout of exercise.

Red and near-infrared light decrease lactic acid production by muscles.

Red and near-infrared light improve mitochondrial function during exercise.

Increases acetylcholine receptors on muscles (this is the neurotransmitter released from nerve cells that stimulates muscle contraction).

Red and near-infrared light increase the production of specific types of heat shock proteins that protect cells from oxidative damage, stress, and apoptosis (early cell death).

Red and near-infrared light also enhance muscle growth, as well as increasing strength significantly.

Red and near-infrared light therapy promotes the development of muscle stem cells, myosatellite cells, which develop into specific varying types of muscles.

Red and near-infrared light also have the profound benefit of increasing mitochondrial adaptations and mitochondrial.

1. Cassie—34 y.o. female with a history of acne and premature wrinkles. In addition, she had difficulty sleeping. In a last-ditch effort to resolve her symptoms, she began using red light therapy for 20 minutes 6 days/week. After 6 weeks, she had a noticeable reduction in acne and a slight reduction in the visibility of her wrinkles. At the 3.5 month mark, her wrinkles were barely visible. She combined red light therapy with GHK-Cu for maximum results. 
2. Jacob—a 26 y.o. male with a history of depression, insomnia, and fatigue. Anti-depressants had a marginal benefit but a host of side effects. He and his provider decided medication was not the correct route for him. He began using red light therapy for 30 minutes per day 7 days per week along with resistance training 3 days per week. At the 2-month mark, Jacob reported a 40% reduction in insomnia and a 30% reduction in depression. At the 4-month mark, he reported a 60% reduction in insomnia and a 50% reduction in depression.
3. Marcie was struggling to lose body fat despite exercising 3-4x per week and improving her nutrition to include more protein and less simple starches. She began using RLT for 30 minutes, with 10 minutes focusing on the abdomen and 10 minutes on the thighs. At the 3 month mark, she had lost close to 1.5 inches from her abdomen and 0.75 inch from each thigh. 
4. Bill—was diagnosed with osteopenia at the age of 62. He knew the risks associated with falls and subsequent fractures. He began using RLT for 30 minutes 5x per week and doing resistance training 3x per week. After 10 weeks, his bone density had improved by over 35%. At the 8-month mark, his bone density had improved by 75% from baseline. Bone density– https://pmc.ncbi.nlm.nih.gov/articles/PMC10139216/
5. Justin was only 41 years old but suffered from low testosterone. His total testosterone was 274 ng/dL. He began using RLT on his testicles for 5-8 minutes 6x per week, fixed his sleep hygiene and began incorporating more protein into his diet. After 8 weeks, his testosterone was now 561 ng/dL. At the 6-month mark, his total testosterone was 712 ng/dL. 

A few small studies and anecdotal reports hint at a potential connection between light therapy and testosterone levels in humans, but a direct link is yet to be robustly demonstrated.

One study in humans has shown that two weeks of light therapy (not strictly red light) improved sexual satisfaction compared with a placebo, but these findings were not correlated with testosterone levels during the conduct of the study.

A separate study on full-body photobiomodulation therapy and its potential impact on reducing inflammation and muscle damage in male water polo athletes found no effect on testosterone during repeated days of water polo matches.

Despite the existence of many anecdotal reports of red light therapy improving libido, energy, and subjective wellness, a direct link has not been demonstrated between this therapy and testosterone levels in robust human research trials.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4428125/

https://pubmed.ncbi.nlm.nih.gov/36358582/

https://pmc.ncbi.nlm.nih.gov/articles/PMC7850666/

Testosterone is produced by Leydig cells in the testes, which convert cholesterol into testosterone via luteinizing hormone.

Interestingly, Leydig cells are rich in mitochondria, meaning they are highly sensitive to changes in cellular energy status. Early evidence from an animal study has shown that photobiomodulation therapy was associated with significant improvements in testosterone levels and a reversal of testicular cell loss. It must be noted, though, that these animals were not healthy; rather, they had experienced a spinal cord injury, which can itself lead to reproductive health problems in males, and/or were subjected to heat stress.

In a separate study on testicular degeneration in rams, LLLT did not improve testosterone concentration.

https://pmc.ncbi.nlm.nih.gov/articles/PMC5992952/

Ahn JC, Kim YH, Rhee CK. The effects of low level laser therapy (LLLT)

on the testis in elevating serum testosterone level in rats. Biomed Res.

2013;24(1):28-32.

https://selfhacked.com/app/uploads/2017/12/the-effects-of-low-level-laser-therapy-lllt-on-the-testis-in-elevatingserum-testosterone-level-in-rats.pdf

https://pubmed.ncbi.nlm.nih.gov/17603859/

Transcranial Photobiomodulation for the treatment of major depressive disorder. The ELATED-2 pilot trial. https://pubmed.ncbi.nlm.nih.gov/30346890/

Seasonal Affective Disorder. https://www.psychiatry.org/patients-families/seasonal-affective-disorder

The potential of transcranial photobiomodulation therapy, for treatment of major depressive disorder. https://pubmed.ncbi.nlm.nih.gov/28231069/

Following are some studies that show how RLT can help your fat loss efforts. In a study from 2011 women between the ages of 18 and 65 were treated with red light therapy twice a week, for 4 weeks, and treatment led to a 0.4 to 0.5 centimeter loss at the waist. In other words, women were losing fat by just putting more light on their bodies. Consequence? Over a period of a year, you may lose several inches by just including red light therapy into your routine. In this other study from 2012, if you received the red light therapy intervention, you’d lose a combined 3 inches from your thighs, waist, and hips. These losses cannot be explained through reduction in the amount of water you hold, but instead, come from body fat reductions. One more study compared the effects of exercise and post-workout red light therapy. Using red light therapy after the workout resulted in greater reductions in body fat than exercise alone. Insulin sensitivity also increased, meaning that the carbohydrates you eat are less likely to be stored as body fat and more likely to be stored in your muscle tissue. A combination of red, infrared, and blue light over 12 sessions led to a loss of 4.5 centimeters in size around the upper abdomen, and about 5 centimeters around the middle and lower abdomen. In other words, those numbers equal more than 2 inches. Yes, again, these women lost abdominal circumference without any exercise.

Efficacy of low-level laser therapy for body contouring and spot fat reduction
https://pubmed.ncbi.nlm.nih.gov/20393809/

Application of low-level laser therapy for noninvasive body contouring
https://pubmed.ncbi.nlm.nih.gov/22362380/

 The effects of exercise training associated with low-level laser therapy on biomarkers of adipose tissue transdifferentiation in obese women
https://pubmed.ncbi.nlm.nih.gov/29473115/

The Effect of Combination of Red, Infrared and Blue Wavelengths of Low-Level Laser on Reduction of Abdominal Girth: A Before-After Case Series
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5642174/

When is the best moment to apply photobiomodulation therapy (PBMT) when associated to a treadmill endurance-training program? A randomized, triple-blinded, placebo-controlled clinical trial
https://pubmed.ncbi.nlm.nih.gov/29185134/

Can low-level laser therapy (LLLT) associated with an aerobic plus resistance training change the cardiometabolic risk in obese women? A placebo-controlled clinical trial
https://pubmed.ncbi.nlm.nih.gov/26398817/

Several studies have shown profound benefits of near-infrared and red light therapy for autoimmune hypothyroidism.

A recent 2013 randomized, placebo-controlled study in hypothyroid patients demonstrated that in people who got nearinfrared light therapy, thyroid function dramatically improved, and remarkably, that thyroid antibody (TPOAb) levels were massively reduced. Amazingly, 47% of patients were able to stop medication completely!

A 2010 study found that red light therapy helped 38% of study participants reduce their hypothyroid medication dose, with a whopping 17 %being able to stop taking the medication altogether!

A 1997 study done in Russia included some data on people with autoimmune hypothyroidism who underwent a thyroid surgery. They found that red/NIR light therapy improved thyroid hormone levels enough that they required, on average, roughly half as much thyroid hormone medication.

A 2003 study done in the Ukraine showed that red light therapy can decrease thyroid medication needs by 50-75% in people with postsurgical hypothyroidism.

A 2010 Russian dissertation study gave red light therapy on the thyroid gland to a group of people with hypothyroidism and found that 17% of people could completely get off thyroid medication and 38% could decrease the dose by 25-50µg.

A 2014 study used the light therapy for 10 sessions with 347 women with subclinical hypothyroidism. At baseline, the average TSH (thyroid stimulating hormone) was 9.1 mIU/L. (Note: Higher TSH is a sign of hypothyroidism). After ten sessions of light therapy, the TSH was normalized in 337 (97%) of these women. Their TSH averaged at 2.2 mIU/L after just 10 light treatments.

Red and near-infrared light therapy is highly effective in treating chronic inflammation. Since chronic inflammation is now being recognized as a major contributor to most chronic diseases from heart disease, depression, and cancer, to Alzheimer’s and chronic fatigue syndrome, this effect of red light therapy on inflammation is a very big deal. Many aging scientists now speak of “inflammaging”— the concept that the genes and pathways that control inflammation may very well be the key drivers of aging and disease. Studies have even shown that red/NIR light therapy can have anti-inflammatory effects on par with non-steroidal anti-inflammatory drugs (NSAIDs), which are the anti-inflammatory drugs routinely prescribed and typically, the over-the-counter drugs people buy when in pain. Combat Depression and Anxiety with Near-Infrared and Red Light Therapy A 2009 study took 10 patients with a history of major depression and anxiety (including PTSD and drug abuse) and gave them four weeks of treatments to the forehead with red/NIR light. Remarkably, by the end of the four-week study, 6 out of 10 patients experienced a remission of their depression, and 7 out of 10 patients experienced a remission of their anxiety.” Though further research is needed, there have been 10 studies so far on the use of red and near-infrared light therapy to treat depression and anxiety related disorders with 9 of 10 studies yielding very positive results.

Red light therapy and near-infrared light therapy have proven to have numerous benefits for oral health and research in this area is booming right now. So far, studies indicate promising results for near-infrared and red light therapy, which has been shown to:

• Combat viral and bacterial infections of the mouth (tonsillitis, herpes, cold sores)
• Facilitate tooth growth/tooth movement and reduce pain for individuals with corrective braces
• Help diabetics with gum problems and periodontal disease
• Reduce mouth pain210 ï Reduce thrush (yeast in the mouth/candidiasis)
• Improve tooth sensitivity
• Fight gum disease and gingivitis

Near-infrared and red light therapy has proven to help women with alopecia to significantly regrow and thicken hair. Near-infrared and red light therapy has also proven to regrow hair in men with hair loss in several studies. Reduce Cellulite with Near-Infrared and Red Light Therapy One study found that when near-infrared and red light therapy is combined with massage, it led to an astounding 71% reduction in cellulite!  Another study that assessed the use of near-infrared and red light therapy on skin health found that “91% of subjects reported improved skin tone, and 82% reported enhanced smoothness of skin in the treatment area.” Speed Up Wound Healing with Near-Infrared and Red Light Therapy Near-infrared and red light therapy are fantastic for wound healing. Red/infrared light accomplishes this in several ways:

• Cleaning up dead and damaged cells in skin (phagocytosis)
• Increasing ATP in skin cells, giving cells more energy to heal themselves ï Increasing the production of fibroblasts
• Increasing blood flow, supplying the wound more oxygen and nutrients needed for repair
• Stimulating the production of collagen and the health of the extracellular matrix100
• Stimulating lymph activity
• Stimulating the formation of new connective tissue and blood capillaries on the surface of the wound.

Therapy Studies show that red light therapy is also effective at restoring energy and vitality in persons suffering with fibromyalgia. Multiple studies have found that near-infrared and red light therapy offers:

• Enhanced quality of life for fibromyalgia patients
• Decreased pain
• Decreased muscle spasm
• Decreased morning stiffness
• Decreased total tender point number in fibromyalgia cases Research – including a very recent 2017 study – suggests that this therapy method is a safe and effective treatment for fibromyalgia.

• Chronic neck pain
• Knee pain
• Fibromyalgia
• Low back pain
• Chronic pain in the elbow, wrist and fingers
• Chronic joint disorders
• Sacroiliac joint pain
• Chronic tooth pain
• Osteoarthritic pain
• Tendinitis and myofascial pain

In a recent systematic review, researchers concluded that red light therapy has proven “beneficial for many individuals suffering from pain, regardless of the condition that is causing it.”

No. The near‑infrared light can pass through many lightweight fabrics. Thin, light‑colored clothing works best.

A gentle, soothing warmth. Many users say they feel looser and more relaxed afterward.

Typical guidance is 20–30 minutes per session, up to twice per day. Start shorter and adjust to comfort, and always follow the quick‑start guide.

No. It’s for general wellness and relaxation and isn’t intended to diagnose, treat, cure, or prevent disease.

Avoid looking directly at the LEDs. Use eye protection if needed and follow the instructions.