Shed Some Red Light On Me

In this Nexus🔗:

📈 Red Light Wave Lengths

🧬 Mechanism of Action of Red Light

✅ Medical Applications of Red Light Therapy

🔴 Benefits of Red Light Therapy Confirmed by Clinical Evidence

♾️ Red Light Therapy and Longevity

❌ Contraindications and Precautions

💡 My Own Experience and Tips for Effective Use

Have you heard about red light therapy? Have you tried it? Well if not, I will try to share some scientific evidence behind its’ relevance and my own experience. Red light therapy, also known as photobiomodulation or low-level laser therapy, is an emerging therapeutic approach that uses low-wavelength red and near-infrared light to stimulate cellular function and enhance tissue repair. Originally developed for medical applications such as wound healing and pain management, red light therapy has expanded into dermatology, sports medicine, and longevity research. By the way, everyone likes before and after pictures, well this article has a lot of that stuff! In this Nexus, I discuss the mechanism of action of red light therapy, its’ benefits, medical applications, the impact on longevity, contraindications for use, as well as my personal experience and some tips.

Red Light Wave Lengths

In order to better understand red light therapy we need to start from the wave lengths, that are used in such therapy. Red light and near-infrared (NIR) light are both part of the electromagnetic spectrum, but they differ in their wavelengths and how they interact with biological tissues. I have summarised its’ main features and differences in the table below:

For therapeutic use, many devices combine both red and NIR light to provide combined benefits, targeting both the skin and deeper tissues.

Mechanism of Action of Red Light

Red light therapy operates primarily by influencing mitochondrial function. When red and near-infrared light penetrates the skin and tissues, it is absorbed by cytochrome c oxidase (CcO) in the mitochondrial respiratory chain. This absorption enhances adenosine triphosphate production (ATP – the source of energy for use and storage at the cellular level), reducing oxidative stress and increasing cellular energy availability. The process also leads to the modulation of reactive oxygen species (ROS), nitric oxide (NO) release, and the activation of transcription factors such as nuclear factor kappa B (NF-κB), which contributes to anti-inflammatory and regenerative effects (1).

In human language, red light therapy works by boosting the energy production inside your cells. When red and near-infrared light enter your skin, they reach mitochondria, which act like power plants in the cells. Mitochondria absorb the light and become more efficient at making energy in the form of ATP molecules, which your body needs to function properly. At the same time, this process helps reduce harmful stress on cells, lowers inflammation, and supports healing. It also triggers the release of beneficial molecules, which improves blood flow, and helps turn on genes that promote repair and regeneration in the body.

Medical Applications of Red Light Therapy

Red light therapy has received FDA clearance for several medical applications. It’s important to note that FDA approval and FDA clearance are distinct regulatory classifications:

• FDA approval indicates that a device is safe and effective for its intended use, typically following rigorous clinical testing.
• FDA Clearance signifies that a device is substantially equivalent to an existing legally marketed device, often through the 510(k) premarket notification process.

FDA-cleared indications for red light therapy are as follows:

1. Treatment of Superficial Skin Conditions. Red light therapy has been cleared for treating actinic keratosis, a common precancerous skin lesion caused by prolonged sun exposure.
2. Hair Loss Treatment. Read light therapy has been cleared for promoting hair growth in individuals with androgenetic alopecia, commonly known as pattern hair loss. Clinical studies have demonstrated significant improvements in hair counts among patients undergoing this therapy.
3. Relief of Minor Aches and Pains. Red light therapy devices have been cleared for providing temporary relief of minor muscle and joint pain, arthritis, and muscle spasms, as well as promoting relaxation of muscle tissue and temporarily increasing local blood circulation.

What Does Science Say?

Benefits of Red Light Therapy Confirmed by Clinical Evidence

As you might already know after some time of reading my Nexus, for me if something is not proven in human, i.e. clinical trials, it doesn’t work. This is because of my knowledge how in vitro (e.g. in cell lines) and preclinical (in animals) data frequently do not translate into directly into human. Thus, the following info is based on the controlled clinical trials. So lets dig in what are the potential benefits of red light and NIR therapy.

Skin Health

Skin health and anti-aging benefits are largely attributed to the enhancement of collagen production and elastin synthesis, which contribute to improved skin elasticity and a reduction in wrinkles. A prospective, randomized, controlled study included 136 volunteers, with 113 subjects assigned to four treatment groups receiving red light therapy (611–650 nm or 570–850 nm) twice weekly. Treatment parameters varied among groups and were compared to a control group (n = 23).

Results demonstrated significant improvements in skin complexion, texture, and collagen density, with blinded evaluations confirming superior outcomes in the intervention groups compared to controls.

Even not being a clinician, you can check the pictures below to see the difference in collagen density and visible changes in skin (2).

Additionally, by stimulating fibroblast proliferation, these processes support wound healing and reduce acne. The modulation of inflammatory responses plays a critical role in improving chronic skin conditions such as psoriasis, eczema, and rosacea, helping to restore skin barrier function and reduce flare-ups.

A clinical study included 16 acne patients who underwent blue light therapy on one side of the face and red light therapy on the other, receiving three treatments at two-week intervals with follow-ups lasting two weeks post-treatment (3). At the final follow-up, total acne lesion improvement rates were 48.0% (in blue light side) and 42.2% (in red light side), with inflammatory lesion reductions of 63.0% and 58.1%, and non-inflammatory lesion reductions of 30.0% and 27.5%, respectively. No significant differences in efficacy were observed. However, blue light therapy was associated with more severe adverse effects, particularly pain and hyperpigmentation. The example of one patient is shown below:

Hair Regrowth

Red light therapy has been clinically proven to stimulate hair regrowth in individuals experiencing androgenetic alopecia (pattern hair loss). It works by delivering red or near-infrared light to the scalp, which is absorbed by mitochondria in hair follicle cells. This process enhances cellular energy production, increases blood flow, and reduces inflammation, creating a more favorable environment for hair growth. Clinical studies have shown that RLT can prolong the anagen (growth) phase of the hair cycle, prevent premature follicle miniaturization, and increase hair density.

A double-blind, randomized controlled trial evaluated the efficacy of red light therapy using a 655 nm wavelength on hair growth in women with androgenetic alopecia (hormone related hair loss) (4). The study involved 47 female participants aged 18 to 60. The active group used a helmet-like device equipped with 21 diode lasers and 30 LEDs, while the sham group’s device contained inactive incandescent red lights. Participants administered treatments at home every other day for 16 weeks, totalling 60 sessions.

Of the 42 participants who completed the study, the active treatment group showed a significant 37% increase in hair growth compared to the placebo group, with no adverse events reported.

Similarly, men undergoing red light therapy have reported increased hair counts and improved scalp coverage (5). A double-blind, randomized controlled trial involved 44 male participants aged 18 to 48, who were assigned to either an active treatment group or a placebo group. Participants administered treatments at home every other day for 16 weeks, totaling 60 sessions.

Of the 41 participants who completed the study, the active treatment group showed a significant 35% increase in hair growth compared to the placebo group, with no adverse events reported.

Pain and Inflammation

Pain management and inflammation reduction are achieved through multiple mechanisms. Chronic pain may be alleviated through the suppression of pro-inflammatory cytokines (signaling molecules produced by immune in response to infection, injury, etc.) while simultaneously enhancing anti-inflammatory responses. Furthermore, muscle soreness is decreased, and recovery time in athletes is accelerated, likely due to improved tissue repair and reduced oxidative stress.

A single-blinded randomized controlled trial evaluated the efficacy and safety of red light therapy for patients experiencing wrist pain (6). 30 participants were randomly assigned to either an experimental group (red light stimulation), or a control group (sham stimulation). Both groups self-administered treatments for 30 minutes daily, five days per week, over a 3-week period, totalling 15 sessions. The primary outcome, measured by the Visual Analogue Scale (VAS) for pain, showed significant reductions in both groups: from 4.93 to 3.67 in the experimental group and from 5.53 to 4.00 in the control group. In addition, only the experimental group demonstrated significant improvements in functional scores and lateral pinch strength. No side effects were reported, suggesting red light therapy was effective and safe for home use.

Eye Health

Recent clinical research indicates that repeated red-light therapy shows promise in controlling myopia progression in children and adolescents. Myopia or nearsightedness, means you can see close objects clearly, but things far away look blurry. Myopia occurs when the axial length of the eyeball is too long or the cornea has excessive curvature. In a randomized clinical trial involving 192 high myopic children aged 7 to 12 years, participants received red light therapy for 3 minutes per session, twice daily, over a 12-month period (7). The results demonstrated a significant reduction in axial length elongation and myopia progression compared to the control group. Specifically, the red light therapy group exhibited an average axial length shortening of 0.11 mm, whereas the control group showed an average axial length elongation of 0.32 mm. Additionally, 59% of participants in the red light therapy group experienced axial shortening greater than 0.05 mm, suggesting a potential reversal of myopic progression.

Athletic Performance and Endurance

Red light therapy has gained attention for its potential to enhance athletic performance and endurance. Clinical studies suggest that red light therapy may improve muscle function, reduce fatigue, and accelerate recovery processes.

In a randomized controlled trial, untrained men underwent an 8-week endurance running program, with one group receiving red light therapy before each session. The red light therapy group exhibited improvements in peak running velocity and 5-kilometer running times compared to the placebo group. Additionally, a moderate effect size was observed for reduced muscle soreness during the third week of training, indicating potential benefits in muscle recovery (8).

Another study investigated the effects of red light therapy on sleep quality and endurance performance in elite female basketball players. Participants who received 30 minutes of red light exposure each night for 14 days showed significant improvements in sleep quality and serum melatonin levels. These enhancements were associated with better endurance performance, suggesting that red light therapy may indirectly boost athletic performance by improving sleep (9).

A comprehensive review of 46 clinical trials involving 1,045 participants revealed that red light therapy could enhance muscle mass gain after training and decrease inflammation and oxidative stress in muscle tissues. The review also noted improvements in muscle performance metrics such as reduced fatigue and increased torque (10).

Red Light Therapy and Longevity

If you would go to any longevity-oriented clinic these days, your will find red light therapy there as an option. Red light therapy has gained attention for its potential role in promoting longevity through mechanisms such as cellular repair, inflammation reduction, and mitochondrial support. By enhancing mitochondrial function and mitigating oxidative damage, red light therapy may have a potential to slow age-related decline in tissues and organs. Key longevity-related mechanisms include:

Telomere maintenance. Telomeres, protective caps at the ends of chromosomes, shorten with each cell division, serving as markers of cellular aging. Chronic inflammation accelerates telomere shortening, leading to cellular senescence. A study published in Nature Communications demonstrated that systemic chronic inflammation exacerbates telomere dysfunction and accelerates aging (11). Thus, in theory, reducing inflammation, red light therapy may indirectly preserve telomere length, thereby supporting cellular longevity.

Stem cell activation. Red light therapy has been shown to enhance the functionality of mesenchymal stem cells. Research indicates that red light therapy can rejuvenate aged mesenchymal stem cells, steering them toward an anti-inflammatory state and enhancing their differentiation potential (12).

Inflammatory balance. Chronic inflammation is a hallmark of aging and contributes to various age-related diseases. Red light therapy has demonstrated anti-inflammatory effects by modulating the activity of transforming growth factor-beta (TGF-β1), a cytokine involved in immune regulation. A study from the University at Buffalo revealed that red light therapy triggers the activation of TGF-β1, which plays a crucial role in regulating stem cell activity, inflammation, and immune system function (13). By restoring inflammatory balance, red light therapy may mitigate the progression of age-associated disorders.

Mitochondrial support. Near-infrared light exposure has been shown to enhance mitochondrial respiration. A study published in Nature Scientific Reports demonstrated that photobiomodulation rejuvenates aged bone marrow mesenchymal stem cells by restoring mitochondrial respiration to levels observed in young cells (14). This enhancement in mitochondrial function may contribute to improved cellular energy production and longevity.

Contraindications and Precautions

Red light therapy is generally very safe. Many studies of different frequency and length of red light therapy application has not reported any major or concerning adverse events. However, there are several contraindications that should be noted:

• Photosensitivity. Conditions such as lupus or certain medications (e.g., tetracyclines, isotretinoin) can increase sensitivity to light.
• Cancer. While red light therapy has been investigated for anti-cancer properties, its effects on tumor cells remain controversial, thus it is not advised.
• Pregnancy. Limited research exists on red light therapy effects during pregnancy, so in case you want to use it, you should consult with your physician.
• Epilepsy. Some individuals with epilepsy may experience photosensitivity reactions, i.e. red light may cause epileptic seizure.
• Hyperthyroidism. Red light therapy may influence thyroid function, potentially exacerbating hyperthyroidism by increasing metabolic activity. Individuals with hyperthyroidism should consult with their physician before use.

My Own Experience and Tips for Effective Use

I have a red and near infrared light device for around a year now, and I really enjoy my red light therapy sessions at home due to two reasons – one I basically can’t do anything else during the session so it is kind of my own way of meditation, second I really like the warming feeling caused by the lamp which seems to come from within. Couple of advices from me:

1. The quality of the device is really important. It is easy to fake red light thus look for a trustful manufacturer, long term on the market and with significant number of verified reviews. Otherwise, you might end up spending time irradiating yourself to a light that doesn’t do anything for you.
2. Wavelength is important. When I was choosing the device, I picked one that had 6 different wavelengths including near infrared light to maximize the benefit.
3. Duration and frequency is important. The key benefits of red light are observed after frequent and continuous use, so don’t expect miracles after 1-2 times or doing sessions once in a while. You have to make it part of your routine for it to work.
4. Distance from light source is important. I see people posting pictures of exposing themselves to red light but being quite far away from the device. This won’t work. The manufacturer will provide you guidance what is the optimal distance from the lamp, but generally it is 15-50 centimetres.
5. Prepare to undress. While near-infrared light can penetrate through thin clothing, red light therapy (in the visible spectrum) is most effective when applied directly to bare skin. For optimal results, ensure the target area is exposed during the session.
6. Safety is always first. Avoid looking directly at the light, and follow manufacturer guidelines for usage. With my device I have received special glasses for eye protection (as you can see in the picture), but usually I just do the sessions with the eyes closed. While red light is used to improve myopia, this shall be done only under physician’s supervision.

Red and near infrared light therapy is a promising non-invasive treatment with diverse applications in medicine, wellness, and longevity. As research evolves around this topic, red light therapy is becoming an integral part of preventive health strategies and age-related interventions. I really enjoyed writing this article, hope you have enjoyed reading it. Make sure to share your experiences or any questions that I haven’t addressed in the article. More on longevity coming soon, stay tuned!