Red light therapy can be used on your face, scalp, joints, muscles, surgical scars, and even your head for brain-related benefits. It has also been applied to the waist, hips, and thighs for body contouring. The key is that different body areas require different approaches, and a few sensitive spots should be avoided entirely.
Face and Skin
The face is the most popular target for red light therapy, and it has the strongest commercial backing. The FDA has cleared red light devices specifically for treating full-face wrinkles, and blue light modes for mild to moderate inflammatory acne. In clinical testing, an LED mask reduced crow’s feet wrinkle depth by about 35% after eight weeks and nearly 39% after twelve weeks. Sebum (the oil your skin produces) dropped even more dramatically, falling by 64% at eight weeks and over 70% at twelve weeks. The number of clogged, bacteria-harboring pores also decreased by about 23% over that same period.
For facial use, holding the device roughly six inches from your skin and treating for about six minutes per session delivers an effective dose. Most at-home masks and panels are designed with this distance built in.
Surgical Scars and Healing Skin
Red light therapy can reduce scarring after surgery by slowing the overproduction of collagen that makes scars thick and raised. In a clinical trial, treated skin showed lower collagen levels at the scar site six months after surgery compared to untreated skin, which is a favorable outcome since excess collagen is what makes scars look and feel worse. Treatment in that study began about one week after surgery, during the early healing phase, suggesting that starting early may be the most effective window. Avoid applying red light to open wounds, active infections, or fresh burns.
Knees, Hands, and Other Joints
Joint pain, particularly from osteoarthritis, is one of the most consistently studied uses. Knee osteoarthritis is the most common form studied, and multiple clinical trials have found that red light therapy reduces pain and improves function in the short term. One study of 25 female patients with rheumatoid arthritis reported that 72% experienced pain relief. Research on hand osteoarthritis also showed reduced pain, though grip strength didn’t improve significantly.
Rheumatoid arthritis most commonly affects the wrists, hands, knees, and ankles, and all of these joints have been targeted in studies. For joint treatment, the device should be placed very close to the skin (within about half an inch) with sessions lasting around 12 minutes, since the light needs to penetrate deeper tissue than it does for surface-level skin concerns. The FDA has cleared infrared light devices for temporary relief of arthritis and muscle spasms through topical heating.
Muscles and Recovery
Athletes and gym-goers use red light therapy on sore muscles after intense exercise. The evidence is real but modest. In one controlled study, participants who received light therapy after exercise-induced muscle damage reported calf soreness of 1.0 out of 10 at the 24-hour mark, compared to 2.3 out of 10 in the untreated group. Soreness stayed lower throughout the full recovery week. However, the same study found no significant difference in quadriceps or hamstring soreness, and overall lower-body soreness didn’t meaningfully change between groups.
The takeaway: red light therapy may take the edge off localized muscle soreness, particularly in smaller muscle groups, but it’s not a dramatic recovery tool. Placing the device directly against or very close to the target muscle works best, since deeper tissues need a higher dose.
Scalp for Hair Growth
Red light therapy applied to the scalp can stimulate hair regrowth in people with androgenetic alopecia (the most common form of hair loss in both men and women). One double-blind trial using a helmet-style device found a 35% increase in hair growth among male participants after 16 weeks of treatment at 25 minutes every other day. An earlier study found even larger gains, with hair count in men improving by 74% in the temporal area and 120% at the crown.
The typical protocol is 15 to 25 minutes per session, three times a week, for at least four to six months. Cap and helmet devices are designed to cover the full scalp evenly. Results take time, and most studies show meaningful changes only after several months of consistent use.
Waist, Hips, and Thighs
Body contouring is a commercially popular but more contentious use. The Zerona laser was the first noninvasive device to receive FDA market clearance for circumferential reduction of the waist, hips, and thighs. In its pivotal clinical trial of 67 participants, the treated group lost an average of 3.51 inches combined across those three areas in two weeks. A larger follow-up study of 689 patients reported an average combined reduction of 5.17 inches.
These results come from professional, multi-head devices used in clinical settings, not small handheld panels. The mechanism appears to involve creating temporary pores in fat cells that allow stored contents to leak out. Results vary, and the reductions are modest compared to surgical options.
The Head for Brain Health
Transcranial photobiomodulation, where near-infrared light is directed through the skull to reach brain tissue, is an active area of research for traumatic brain injury, cognitive decline, and mood disorders. In one case, a 23-year-old athlete with six prior concussions received a combination of intranasal and transcranial light therapy for eight weeks and showed increased brain volume, improved cerebral blood flow, and better scores on neuropsychological tests. A study of four former football players with suspected chronic traumatic encephalopathy (CTE) found significant improvements in cognition and mood after 18 treatment sessions.
For TBI patients, light has been applied to the forehead (twice daily in one study, which increased blood flow in the frontal lobe by 20%), to the side of the head where a stroke occurred, and to specific brain network areas during at-home treatment. Research also suggests benefits for sleep: chronic TBI patients gained an average of one extra hour of sleep per night. This application remains largely experimental and is typically guided by a clinician.
Whole Body for Sleep
A study on Chinese female basketball players found that 30 minutes of whole-body red light exposure every night for 14 days significantly improved sleep quality and reduced the time it took to fall asleep. Melatonin levels in the treated group rose to 38.8 pg/mL, compared to 23.8 pg/mL in the placebo group. Unlike blue and green light, which suppress melatonin and keep you alert, red wavelengths (around 610 to 660 nm) do not interfere with your body’s melatonin production and may actually help it start earlier in the evening. The treatment was delivered while lying face-up under a full-body light panel.
Where Not to Use It
A few areas and situations call for caution. Avoid shining red light directly into your eyes, especially if you have glaucoma, cataracts, or have had recent eye surgery. Most at-home face masks are designed to protect the eyes, but standalone panels are not.
The thyroid gland, located in the front of your neck, is another area to protect. If you have hyperthyroidism or take thyroid medication, avoid directing the light at your neck. Even when treating the jawline or chin for skin concerns, try to keep the beam away from the thyroid area.
Red light therapy is generally not recommended for people with photosensitivity conditions, active cancer, or seizure disorders. Most experts also advise against using it on the abdomen or lower back during pregnancy.