Red Light Protocols

660 nm is visible red light and penetrates the skin roughly 1–4 mm — used for skin, scars, scalp and wounds. 850 nm is near-infrared (invisible) and passes through tissue roughly 3–5 cm — used for muscles, joints and deeper pain areas. Combo therapy (660 + 850 nm simultaneously) combines superficial and deep effects.

For most areas, 3–5 sessions per week is enough — tissues need recovery time between exposures. Skin and face protocols tolerate 4–5 sessions weekly, while deep joint work usually stays at 3 per week. Daily use does not speed up results, and overly frequent exposure can actually reduce the response due to the biphasic dose curve.

660 and 850 nm are non-ionising light with no known long-term harm when guideline times are followed. Eyes should always be protected from direct exposure — bright light can damage the retina. Pregnancy, active cancer, photosensitising medication and undiagnosed symptoms warrant a medical review first. Mild warmth on the skin is normal; stinging or redness means the session was too long.

Red light follows a biphasic response (Arndt–Schulz law): a small dose activates mitochondria, but too much overloads them and produces oxidative stress. In wound-healing studies, 2 J/cm² promoted healing while 50 J/cm² slowed it. More is not better — recommended times reflect the dose that gives the best biological response, not the maximum tolerated.

Yes, but only under conditions. The 850 nm near-infrared must be turned off, because it is invisible and the blink reflex does not limit exposure. The protocol is 660 nm alone, from at least 30 cm, 20–60 seconds once per day in the morning. The evidence covers the method, not this device: research devices delivered 8–40 mW/cm², and the panel's radiance has not been measured for ocular use. Diagnosed eye disease belongs with an ophthalmologist. See the conditional eye protocol on this page in full.

The evidence here is strong, but the dose is delivered with an intraoral tip directly against the mucosa at just a few J/cm² per point. A panel does not reach the mucosa and does not pass through the cheek at a therapeutic dose. The TMJ protocol on this page targets the joint and masseter under the skin, not the mucosa. Oral mucosa issues belong with a dentist.

The thyroid sits superficially at the front of the neck and is unavoidably exposed if the neck is lit from the front. Hashimoto's studies show promising results in supervised clinical use, but that does not justify home use over the thyroid. If you have thyroid disease, nodules or thyroid medication, talk to a doctor before lighting the neck. For neck and shoulder work, aim from behind.