Red Light, Healthy Life: What the Science Really Says About Red Light

A large red sun setting over the horizon

Our new design shows someone kicking back under a big red sun, and it got us curious. Is red light actually good for you, or is it just another wellness trend? We read the research so you don't have to. Here's what holds up, what doesn't, and how to get more red light into your day without buying anything.

What is red light therapy?

Red light therapy (also called photobiomodulation or low-level light therapy) uses low-power red light, around 630–670 nm, and near-infrared light, around 800–850 nm. It doesn't heat or burn the skin, and unlike UV light it hasn't been linked to skin cancer. The leading theory is that this light is absorbed by the mitochondria (the "batteries" in your cells), helping them make more energy (ATP). That energy may then support repair, circulation and lower inflammation. Researchers still consider this mechanism a working theory.

What the science supports

1. Skin: subtle but real

The American Academy of Dermatology says studies of LED red light show subtle to noticeable improvements in fine lines, roughness, redness and loose skin. Dermatologists also use it in the office for acne and aging skin, usually alongside other treatments. The AAD calls the results encouraging but limited: devices and study designs vary a lot, and the best home dose isn't settled yet.

2. Hair: the most mainstream use

Low-level light devices for hereditary hair loss have been FDA-cleared since 2007 for men and 2011 for women. In sham-controlled trials, users ended up with more hair per square centimeter after about 26 weeks. Keep expectations realistic: it can thicken what you have, but it won't regrow a full head of hair. Also note that "FDA-cleared" means the FDA considers the device low-risk. It doesn't prove the device works.

3. Medicine: a real clinical tool

The strongest clinical use is in cancer care. International guidelines from MASCC/ISOO recommend photobiomodulation to prevent painful mouth sores (oral mucositis) in some patients having head-and-neck radiotherapy or stem-cell transplants. This is done by clinicians, not at home. Even here, a 2024 umbrella review rated most of the underlying research as low quality and called for larger trials.

4. Promising but early

  • Blood sugar: In a 2024 University College London study, 30 healthy adults got one 15-minute dose of 670 nm red light on the back. After a glucose drink, their blood-sugar levels were 27.7% lower than in the no-light group, and their peak was 7.5% lower (Journal of Biophotonics).
  • Vision: In a 2021 study, 20 adults looked at deep red light for 3 minutes in the morning. Their color-contrast vision improved by about 17% on average, and the effect lasted about a week. The same dose in the afternoon did nothing (Scientific Reports).

Both studies are small, so treat them as interesting leads, not proven benefits.

What it doesn't do (yet)

According to Cleveland Clinic, there's no good evidence that red light helps with weight loss, cellulite, cancer treatment, depression or seasonal affective disorder. Be wary of any product that promises those results.

Where the sun comes in

You don't need a device to get red light. Sunlight naturally contains a full range of red and near-infrared light, and morning and evening light are especially warm. Glen Jeffery, the UCL scientist behind the blood-sugar study, has pointed out that modern LED lighting is heavy on blue and light on red. He suggests spending more time in sunlight as a partial remedy.

Morning light also matters for sleep. A 2025 study of 1,762 adults in BMC Public Health found that every 30 minutes of sun before 10 a.m. was linked to an earlier sleep schedule (the middle of the night's sleep shifted about 23 minutes earlier) and to better sleep quality. That study shows a link, not proof of cause and effect, but it fits a lot of earlier research on light and your body clock.

The catch: sunlight also contains UV light. Get your sun in the early morning or at golden hour, keep midday sessions short, and wear sunscreen whenever you'll be outside for a while.

How to bring more red light into your day

  • Take a morning walk. Spend 10 to 30 minutes outside before 10 a.m., without sunglasses if it's comfortable, but never look straight at the sun.
  • Catch golden hour. An evening walk or patio session gives you warm light with less UV.
  • Warm up your evenings. Dim the lights and use warm bulbs after sunset.
  • If you buy a device, choose an FDA-cleared one, follow the directions, and wear the eye protection it comes with. Talk to a dermatologist first if you take medication that makes you sensitive to light or have a light-sensitive condition.

Red light, healthy life

That's the idea behind our new drop: slow down, step outside, and let the warm light do its thing. Phone in your pocket, face to the sun. Bring the color back.

This article is for general information only and isn't medical advice. Talk to your doctor or a board-certified dermatologist before starting any light therapy.

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