What Is Red Light Therapy?
Many assume that red light therapy is simply a red LED you can shine anywhere on your body that you want to reduce inflammation, recover from a workout, or experience an aesthetic glow-up. But it’s not that simple.
Red light therapy, also known as photobiomodulation (PBM), is a noninvasive treatment that uses low-level red or near-infrared light to stimulate your cells and encourage healing and repair—addressing a fundamental cellular energy problem.
Long before red light therapy became a wearable wellness hack, NASA discovered that red light had wound-healing properties while conducting experiments on plant growth, after which LED therapy began to be used by the military and professional sports teams before becoming more accessible to consumers (Cotler, 2015).
Despite decades of research, conventional medicine has been slow to adopt it, often labeling it as experimental or alternative, defaulting instead to pharmaceuticals or surgical interventions for the conditions it addresses.
Conventional treatments certainly have a place, but red light therapy can fill certain gaps.
How Does Red Light Therapy Work?
When your tissues are injured, experiencing inflammation, or otherwise impaired, your mitochondria (the energy-producing “powerhouse” of your cells) can't function normally.
They produce less ATP (your cells' primary energy currency), leading to reactive oxygen species (free radicals) building up and contributing to cellular stress and damage. Over time, your body's innate repair processes stall.
This is what can eventually manifest as things like (Naharro-Rodriguez et al., 2025):
Signs of accelerated aging
More noticeable fine lines and wrinkles
Less skin elasticity
Hyperpigmentation (dark spots), and
Inflammation
When red light therapy is applied, you're exposing your skin to specific wavelengths of red light (630-660 nanometers) for surface tissue applications or near-infrared light (810-850 nanometers), which goes deeper into muscle, joint, and connective tissues (Herrera et al., 2024).
Red light therapy is absorbed by the mitochondria. This essentially kicks them back into gear, increasing energy production, targeting harmful free radicals, and supporting repair and regeneration where it's needed.
Not all red light therapy devices are the same, though. Power density, the amount of light energy delivered per unit of surface, matters as much as wavelengths.
Clinical-grade devices are designed to deliver high therapeutic doses, whereas most consumer LED devices deliver much lower doses.
This means that while the light from a home mask reaches your skin, it may not be intense enough to promote meaningful changes at a deeper cellular level.
That’s not to say home devices aren’t worth it, but it’s important to know that clinical data doesn’t automatically apply.
Who Does Red Light Therapy Help?
Red light therapy is predominantly sought out by individuals dealing with unwanted skin or hair-related cosmetic issues. It's still being studied for other marketed uses.
Outcomes also depend on your body's capacity to respond. Things like nutritional status, stress resilience, and sleep quality all factor into your cellular response to treatment.
Common Uses
The most common applications include signs of accelerated skin aging, such as wrinkles and reduced elasticity, acne, sun damage, and hair loss from androgenetic alopecia (pattern baldness).
Less common but curious areas where it may eventually prove useful include tendinopathy, arthritis, pain management, dementia, dental pain, anxiety, muscle recovery for sports performance, spider veins, and weight loss.
What the Evidence Supports
The strongest evidence for red light therapy centers on the following areas:
Skin Repair and Wound Healing
Randomized controlled trials support PBM for reducing fine lines, improving skin roughness, and speeding up wound healing (Wunsch et al., 2014).
It’s effective for stimulating collagen production, reducing inflammation, and promoting cellular turnover. This is one area where clinical and consumer-grade devices overlap, as surface-level skin uses don’t need nearly as much penetration as some other uses.
Musculoskeletal Pain
PBM can help reduce pain and improve function in knee osteoarthritis, with a systematic review of 10 placebo-controlled trials confirming (Oliveira et al., 2024).
There’s some evidence for tendinopathy, but optimal uses are still being determined.
Muscle Recovery and Sports Performance
A 2025 comprehensive review found PBM stimulates recovery processes in athletes related to lowering inflammation, activating muscle repair cells, and producing mitochondrial ATP—with observed effects including regeneration, improved strength and endurance, and reduced injury (Miejska-Kamińska et al., 2025).
Blood Vessel Function
Healthy blood vessels are essential for your circulatory system to run properly, delivering oxygen and nutrients throughout the body and efficiently returning blood to the heart.
A review of 50 selected studies concluded PBM can address blood vessel dysfunction, improving inflammation, cellular growth, and circulation, with possible implications for hypertension and poor wound healing (Colombo et al., 2021).
Mood
PBM may be a helpful complementary therapy for addressing certain mental health conditions related to mood.
For instance, a systematic review of 17 studies concluded PBM is safe and potentially effective for major depressive disorder, though research remains early-stage (Caldieraro & Cassano, 2019).
Age-Related Macular Degeneration (AMD)
AMD is the leading cause of irreversible vision loss among adults over 60, causing wear and damage to the retina, which is responsible for sharp eyesight.
A 2023 review found PBM showed potential for improving vision parameters and reducing AMD lesions. Notably, red light therapy is already FDA-authorized and EMA-approved for intermediate AMD (Fantaguzzi et al., 2023).
Note that systematic reviews are only as good as the studies they include, and many have limitations, including varying devices, small samples, and a lack of standardized controls.
Still, the safety profile for red light therapy in skin, wound healing, and musculoskeletal uses is solid and clinically backed.
Where the Evidence Is Limited
Studies on PBM across multiple health outcomes use widely different wavelengths, power densities, session durations, and treatment frequencies, making it difficult to draw firm conclusions (Son et al., 2025). There's more gray area than certainty for:
Dementia and brain function decline: Early studies have shown meaningful improvements in mild-to-moderate dementia, but effects appear temporary and stop when treatment stops (Lim, 2024).
Weight loss: The proposed mechanism makes sense, but studies use small samples, short follow-up periods, and inconsistent protocols (Kim et al., 2017).
Anxiety: A 2019 pilot study showed potential benefit for generalized anxiety disorder, but larger trials with standardized dosing are needed (Maiello et al., 2019).
Most research has been conducted using clinical-grade devices, not home devices. The evidence, while encouraging, can't automatically translate to consumer-level products. That doesn't mean home devices don't work—it just means they’re probably best used as one part of a larger wellness routine.
Safety and Regulation
Most red light therapy devices are FDA-cleared but not FDA-approved, meaning they don't undergo the same rigorous review as higher-risk medical devices. They're generally classified as class II (moderate risk) devices—unlike class III devices such as surgical implants and pacemakers.
Red light therapy has a well-established short-term safety profile and is one of the more thoroughly studied noninvasive wellness modalities available. Long-term data is still being collected, which is true of most emerging therapies, but current evidence doesn’t raise red flags.
Eye safety is worth noting: staring directly into red light is not recommended, as it could damage the retina, particularly with higher-powered devices. Most practitioners will have you wear eye protection.
A 2019 systematic review of 22 studies in 380 pregnant women found laser treatment safe in all trimesters, though research in this area remains limited (Wilkerson et al., 2019). Other contraindications include active malignant lesions, medications that increase light sensitivity, light-sensitive conditions such as lupus or porphyria, and photosensitive epilepsy. People with pigmentation conditions like melasma should also use caution, as certain wavelengths can worsen pigmentation in some individuals.
One last thing: the saying “the dose makes the poison” likely applies to red light therapy, too. Whether red light therapy poses safety risks depends on the duration, distance, frequency, and proper use.
The Experience
Most providers recommend arriving without lotions, creams, oils, or cosmetics and staying well hydrated. Avoiding direct sunlight for a few days beforehand may also be advised.
Sessions are straightforward: a face or neck treatment involves sitting or lying down with opaque eye goggles while the provider applies the light; scalp treatments use a hood or flexible cap; and for muscle recovery, panels are placed close to the affected area.
Sessions typically run 10 to 30 minutes, with multiple sessions per week being common.
There's no downtime. Staying hydrated and avoiding harsh products post-treatment is recommended; a hydrating serum like hyaluronic acid may help lock in moisture.
The Future of Red Light Therapy
Promising research is underway to extend PBM's applications into mental health, pain, recovery, vision, and neurodegenerative conditions.
Current clinical trials include treatments for myopia, peripheral artery disease, depression in aging populations, post-COVID fatigue, radiotherapy side effects, Parkinson's disease, and post-operative wound healing.
Takeaway
Red light therapy is a low-risk, noninvasive treatment with well-supported applications in skin health, wound healing, musculoskeletal pain, and muscle recovery. It also has a growing body of research pointing toward broader uses.
While it's not a one-size-fits-all option or a standalone solution, it's an exciting, expanding field worth watching—and perhaps trying out for yourself.
