Red light therapy works best when you expose bare skin to the light at a consistent distance, for 10 to 20 minutes per session, several times a week. The specifics vary depending on your goal, whether that’s skin health, pain relief, or muscle recovery, but the core principles stay the same: right wavelength, right duration, right frequency, and direct skin contact.
Wavelengths That Matter
Red light therapy devices use two main wavelength ranges. Standard red light falls between 630 and 700 nanometers (nm), with 660 nm being the most common. This range is effective for skin-level concerns like collagen production, wound healing, and reducing inflammation close to the surface.
Near-infrared light, typically around 850 nm, penetrates deeper into muscle, joint, and connective tissue. It promotes blood flow through vasodilation, which helps with tissue repair, pain relief, and reducing deeper inflammation. Many devices combine both wavelengths, giving you surface and deep-tissue benefits in a single session. If you’re choosing a device, look for one that offers 660 nm, 850 nm, or both.
Session Length and Distance
Most devices work well with 10 to 20 minutes per session. The ideal distance from your body depends on the device’s power output, but a general starting point is 6 to 12 inches from the skin. Panels with higher output can be used from slightly farther away, while smaller handheld devices need to be closer. Your device’s manual will give you the best guidance here, since power varies significantly between products.
More is not better. Red light therapy follows what researchers call a biphasic dose response: low-to-moderate doses stimulate and repair tissue, while excessive exposure can actually inhibit those benefits. Think of it like watering a plant. The right amount helps it grow; too much drowns it. Sticking to the 10 to 20 minute window keeps you in the productive range.
How Often to Do It
Your frequency should match your goal:
- Skin rejuvenation and anti-aging: 3 to 5 sessions per week is a solid starting point. Consistency matters more than intensity here.
- Pain, inflammation, or muscle recovery: Daily sessions for the first 2 weeks can help build momentum, then taper to 2 to 3 times per week for maintenance.
Avoid doing daily sessions for more than 2 to 3 weeks without a break. Giving your body time to respond between sessions is part of how the therapy works. If you’re not seeing results after several weeks, adjusting your distance or session length is more productive than simply adding more sessions.
Bare Skin Gets the Best Results
Red light can technically pass through clothing, but fabric scatters and absorbs the light, reducing how much actually reaches your tissue. For anything requiring deep penetration, like joint pain or muscle recovery, bare skin is significantly more effective.
If you need to keep some clothing on, choose light-colored, thin, breathable fabrics like white cotton or linen. Avoid dark colors, thick materials, and shiny or textured fabrics, all of which block or reflect more light. But whenever possible, uncover the area you’re targeting.
Timing Around Workouts
If you’re using red light therapy for exercise performance or recovery, when you use it relative to your workout matters.
Pre-workout sessions have shown mixed results in research. Some studies found that applying red light to muscles before exercise increased the number of repetitions people could perform and reduced markers of muscle damage in the blood, like creatine kinase. A study on biceps contractions, for instance, found that 30 seconds of 830 nm light before exercise improved endurance and lowered lactate levels. But other studies using similar protocols found no significant effect on muscle performance itself, though blood markers of damage still improved.
Post-workout use has more consistent support. Applying red light after exercise helps reduce delayed-onset muscle soreness (DOMS). One study found that a combination of 660 nm and 880 nm light applied to the biceps after exercise significantly reduced soreness at the 48-hour mark. Post-exercise sessions also appear to support muscle and energy gains while protecting against oxidative stress.
If you’re choosing one, post-workout is the more reliable option. If you have time for both, a brief pre-workout session followed by a longer post-workout session covers both bases.
Eye Protection
You don’t necessarily need goggles for every session, but there are situations where they’re important. If you find yourself staring at the LEDs or if the light feels uncomfortably bright even with your eyes closed, wear protection. Children should always wear light-blocking goggles because their eyes are still developing and more sensitive to intense light.
The best option is opaque, light-blocking goggles that fit snugly around your eye sockets, similar to swim goggles but completely blacked out. These come included with many quality devices. Color-filtering glasses (usually green-tinted) are another option, but full light-blocking goggles provide more reliable protection. If you’re treating your face or chest where the light will inevitably reach your eyes, goggles are worth using every time.
Who Should Avoid It
Red light therapy is generally safe, but certain conditions and medications create real risks. People with retinal diseases, including those with diabetes-related eye damage, should avoid it. The same goes for anyone with a history of skin cancer or systemic lupus erythematosus.
Several medications increase your sensitivity to light and can cause adverse reactions. These include lithium, melatonin supplements, certain antipsychotics, and some antibiotics. If you take any photosensitizing medication, check with your prescriber before starting red light therapy. The interaction isn’t about the red light being dangerous on its own; it’s that these drugs change how your cells respond to light exposure.
Putting It All Together
A practical routine looks like this: pick a consistent time of day, expose bare skin to your device from the recommended distance, run it for 10 to 20 minutes, and repeat 3 to 5 times per week. Start at the lower end of session length and frequency, then increase gradually over the first few weeks. Results for skin concerns typically take 4 to 8 weeks of consistent use. Pain and inflammation may respond faster, especially with the daily-then-taper approach.
The biggest mistake people make is inconsistency. A 15-minute session three times a week for two months will outperform sporadic 30-minute sessions. Keep it simple, keep it regular, and let the cumulative effect build.