Red Light Therapy and Pain: The Melatonin Your Cells Make in Daylight

If you spend nearly all day indoors and your inflammation and pain never quite settle, the light you are missing may matter more than you think. This article explains photobiomodulation—how sunlight, and specifically its infrared wavelengths, affects your cells—and the surprising link Dr. Padda draws between that light and a hormone most people know only as a sleep aid: melatonin. Every claim here comes from his presentation, and the ideas below are best understood as an emerging, practice-based way of thinking about metabolic inflammation, not settled standard care.

The part of sunlight you never see is the biggest part

Sunlight is far more than the visible light we read and see color by. It spans a wide spectrum, and of the light we are actually exposed to, roughly 6.8% is ultraviolet, 39% is visible, and about 54% is infrared or near-infrared. Shorter wavelengths penetrate the body only slightly, while longer infrared wavelengths reach deep—infrared can pass through bone, into the fluid around the brain, and spread widely. In other words, the majority of the light your body evolved to use is invisible to your eyes.

How infrared light switches on melatonin inside your cells

Most people think melatonin comes from the pineal gland at night. But Dr. Padda notes that pineal melatonin is only about 5% of what your body makes. The other 95% is produced locally inside the mitochondria of nearly every cell and is used right where it is made. Near-infrared and infrared light are absorbed by an enzyme called cytochrome c oxidase—whose iron-containing core is highly reactive to that light—improving the mitochondrial membrane potential and helping trigger this local melatonin. Making it also requires the raw materials tryptophan (converted to serotonin) and the cofactor acetyl-CoA.

Why missing this light can leave you inflamed

Inside the mitochondria, energy production constantly generates free radicals. Melatonin is a potent scavenger that quenches them; Dr. Padda describes it as an even larger antioxidant system than glutathione. When cellular melatonin runs low, those free radicals build up and can push cells toward damage and self-destruction. Because we now spend the great majority of our lives indoors—and because modern LED and CFL lighting emits almost no infrared, unlike the incandescent bulbs of the past—he argues we may be losing the daytime light that keeps this anti-inflammatory system running.

What this means at the Padda Institute

Dr. Padda frames infrared and near-infrared exposure as a low-cost, low-risk tool he already uses clinically to help patients with pain and metabolic inflammation, alongside blood testing that documents that inflammation. He also mentions using green-light glasses for patients with severe migraine that resists standard therapies. These remain investigational, practice-based approaches that he offers as part of a broader plan, not a proven cure. A caution he stresses: high-dose melatonin supplements (people often take 5–10 mg versus cited human doses near 1 mg) may actually work against long-term sleep. Individual results vary.

Frequently asked questions

What is photobiomodulation, and how could it help my pain?

Photobiomodulation is the effect of light—especially near-infrared and infrared wavelengths—on your cells. Dr. Padda explains that this light is absorbed by mitochondria and helps them produce melatonin locally, which acts as a potent antioxidant and anti-inflammatory. He uses infrared and near-infrared clinically for pain and metabolic inflammation, but it is an emerging, practice-based approach rather than settled standard care. Individual results vary.

Isn't melatonin just for sleep?

Only about 5% of your melatonin comes from the pineal gland and relates to your sleep-wake cycle. The other 95%, according to Dr. Padda, is made inside your cells' mitochondria during the day and used locally as one of your strongest free-radical scavengers. That is why he argues daytime infrared light exposure matters for inflammation and pain, not only for how well you sleep.

Should I buy a red light device or take melatonin supplements on my own?

Do not start, stop, or change any medication or supplement without consulting your physician. Dr. Padda specifically warns that the high melatonin doses many people take may undermine long-term sleep, and infrared light is best used as part of a supervised plan that includes evaluating your metabolic inflammation. Discuss any device or supplement with your doctor first. Individual results vary.

Where are you located and how do I book?

Padda Institute Center for Interventional Pain Management, 4477 Woodson Road, Suite 100, St. Louis, MO 63134. Book at painmd.tv/appointment/ or call (314) 481-5000.

Key takeaways

• Mechanism: infrared light is absorbed by mitochondria and helps them make melatonin, a potent antioxidant, right inside your cells.
• Evidence status: an emerging, practice-based idea for metabolic inflammation and pain, not proven standard care.
• Why timing matters: this melatonin is made in daytime light, and indoor life plus LED lighting emit almost no infrared.
• Next step: ask about infrared light and metabolic-inflammation testing—book at painmd.tv/appointment/.

Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP — Board Certified in Anesthesiology, Pain Medicine, Interventional Pain Management, Addiction Medicine, and Obesity Medicine. Last reviewed July 2026.

This article is educational and is not a substitute for evaluation, diagnosis, or treatment by a physician. Individual results vary. Do not start, stop, or change any medication without consulting your physician.

Dr. Gurpreet Singh Padda, MD, MBA, MHP , MD, MBA, MHP