Red Light Therapy

How it works

Red and near-infrared light are absorbed by your mitochondria, the part of the cell that produces energy. Absorbing that light makes them produce more.

More cellular energy means more of whatever that cell does. Skin cells make collagen. Follicles hold hair in its growth phase longer. Muscle tissue recovers faster.

The mechanism is well established. The full picture is still being worked out.

The wavelengths

415nm (blue) Stops at the surface. Acne only. Kills acne bacteria.

630–660nm (red) Reaches a few millimeters deep, into the skin. Collagen, elastin, tone, texture, wound healing, hair follicles.

810–850nm (near-infrared) Passes deeper, into muscle, tendon, and joint. Circulation, inflammation, soreness, deeper repair.

Near-infrared is nearly invisible. How bright a device looks tells you nothing about its strength.

What the evidence supports

Strong

Skin aging. Red light at 660nm, 10 sessions over 4 weeks, cut wrinkle volume around the eyes by about 30% in a 137-woman trial. The same trial found no change in hydration or firmness.

Acne. Blue light, alone or with red. FDA-cleared, decades of trials. Real but modest, for mild to moderate acne.

Hair loss. A 2025 review of 38 studies and over 3,000 patients found significant hair density gains versus placebo devices, in both men and women. A 12-month trial using a helmet 3 times a week saw hair count rise about 25% by week 48, with the first real gains at month 4.

Wound healing.

Moderate

Muscle soreness. Modest evidence, and only when used before exercise, not after.

Joint and muscle pain. Positive results, but study protocols vary so widely they're hard to compare.

Thin or unsupported

Strength. A 2025 review of elite athletes found no measurable gain. Light doesn't make you stronger.

Fat loss, metabolism, thyroid, testosterone, systemic anti-aging. Heavily marketed. Not established.

The pattern: the closer the tissue is to the light, the better the evidence.

Dose

Three things determine how much light you actually get: how strong the device is, how long you use it, and how far you sit from it.

Stronger is not better. Light works in a window. Too little does nothing. Too much reduces the effect and can reverse it. This is why good devices have fixed timers, and why doubling your session isn't a shortcut.

Distance matters more than time. Move a panel from 6 inches to 3 feet and you're getting a small fraction of the light. Farther isn't gentler. It's less, and possibly not enough to do anything.

Masks and helmets sit against you, so distance is handled for you. With a panel, it's the variable you control and the one most people get wrong.

The devices

Mask: Face and neck. Sits against the skin, so the dose stays consistent. Red and near-infrared, sometimes blue. About 10 minutes. Flexible silicone contours to the face; rigid masks leave gaps at the nose and under the eyes.

Helmet or cap: Scalp. Hands-free, automatic timing. Red only, 650–680nm. Near-infrared passes below the follicle and adds little. What matters: how many diodes, total output, and coverage. Follicles that don't get light don't respond. Lasers and LEDs both work; neither is clearly better.

Panel Body. Red and near-infrared. Most flexible, most room for error, since distance and time are yours to manage. Panel size decides how much you can treat at once.

Wrap or handheld: One joint or muscle. Contact keeps the distance fixed.

Bed or full-body unit: Coverage and convenience. A 2025 review found no consistent benefit from whole-body use. Targeted treatment has better support.

What to look for

Exact wavelengths, in nanometers. Skin: 630–660nm and 810–850nm. Hair: 650–680nm. Acne: 415nm. "Red light" or "infrared" with no numbers is a non-answer.

Published output, and the distance it was measured at. The most-hidden and most-important number. Measured at the bulb instead of at treatment distance is a number you'll never actually receive.

FDA clearance you can verify. It's searchable in the FDA's public database. Often implied, less often held.

Trials on the actual device, not general research on light therapy.

Coverage that matches what you're treating.

A fixed timer. Automatic shutoff for proper dosage control.

Ignore: EMF ratings, "medical grade," pulsed vs. continuous, and blue light unless you're treating acne.

Protocols

Skin Clean, dry, bare. No serums first. 10 minutes, 3 to 5 times a week. Serum and moisturizer after. Judge it at 8 to 12 weeks.

Hair Dry scalp, hair parted or loose. 20 to 25 minutes, 3 times a week. More often doesn't help. Judge it at 4 to 6 months. Maintained with use. Reverses if you stop.

Body Bare skin, 6 to 12 inches from the panel. 10 to 20 minutes, 3 to 5 times a week. Before exercise, not after.

Consistency beats intensity. It's cumulative.

Safety

No UV, no DNA damage. Side effects are limited to mild, temporary redness or warmth.

Ask your physician first if you take photosensitizing medications, including some antibiotics, retinoids, and psychiatric medications.

Avoid if you have a photosensitivity condition like lupus or porphyria, over undiagnosed skin lesions, and during pregnancy, which hasn't been studied for these devices.

AEREA carries iRESTORE, which publishes its wavelengths and output and holds FDA clearance on its hair devices.

aerea.online

Educational, not medical advice. Speak with a qualified professional about your own circumstances.