Woman resting her forearm under a small red LED light therapy panel on a table

Red light vs near-infrared light: what's the difference for skin

What is the difference between red light and near-infrared light?

Wavelength. In skin devices, red light sits around 630 to 633 nm and is visible. Near-infrared sits around 830 to 850 nm and is invisible. A modeling study found longer wavelengths penetrate deeper into skin. In one trial, red alone, near-infrared alone and both together all reduced wrinkles, which is why most masks combine them.

Part of the Glow Protocol guide. Start here: The Glow Protocol

Five things worth knowing

They are neighbors on the spectrum. Near-infrared starts where visible red ends.
Near-infrared reaches deeper in modeling. Penetration increased with wavelength.
Both have skin trials. One trial tested each alone and together, and all three improved wrinkles.
Near-infrared light is not an infrared sauna. One is low-level light. The other is heat.
Hydration does not make either go deeper. Lab optics research points the other way.

Red vs near-infrared, side by side

	Red light	Near-infrared light
Wavelength in skin devices	About 630–633 nm	About 830–850 nm; one mask also lists 1072 nm
Can you see it?	Yes	No
Depth in a skin model	Shallower	Deeper; penetration increased with wavelength
Skin trials in this article	633 nm alone reduced wrinkles; 611–650 nm light raised collagen density	830 nm alone reduced wrinkles; 850 nm was part of a home mask that improved crow's feet
Heats the skin?	Described in the trial as non-thermal	Low-level light therapy; not the same as infrared heat

Illustration of a block of layered skin with two beams: a bright red beam ending in the middle layer and a darker near-infrared beam reaching the bottom layer — *In modeling studies, longer wavelengths reach deeper into skin. Illustration, not to scale.*

Does near-infrared light go deeper than red light?

In modeling, yes. A 2017 study used computer simulation of a multi-layered skin model and found that penetration depth increases with wavelength, with a maximum calculated depth of 5,378 μm, about 5.4 mm. Near-infrared has a longer wavelength than red, so it reaches deeper in that model. Deeper does not automatically mean better results.

Three details from that study (Ash and colleagues) are worth knowing.

It is a simulation. The authors used Monte Carlo modeling, a standard way to estimate how light travels through skin. It did not measure results in people.
Skin tone was one of the factors it examined, along with wavelength and the shape of the beam.
A wider beam added little. A 10 mm beam delivered 73 to 88% of the light an infinitely wide beam would at depths of 1 to 3 mm.

What the skin trials found for each

Lee 2007 is the cleanest comparison. Seventy-six people with facial wrinkles were randomly split into four groups: 830 nm alone, 633 nm alone, both together, or a sham light. Sessions were twice a week for four weeks on one side of the face. All three treatment groups had significant reductions in wrinkles, up to 36%, and increases in elasticity, up to 19%, against baseline. Skin samples showed more collagen and elastic fibers in all treatment groups. The authors concluded that 830 and 633 nm LED phototherapy is an effective approach.

Wunsch 2014 tested a wider spectrum. Of 136 volunteers, 113 were treated twice a week for 30 sessions with either 611–650 nm light or a broader 570–850 nm spectrum, and 23 were controls. Both improved complexion, roughness and collagen density against controls. The broader spectrum showed no advantage over the red-only one.

Park 2025 tested the two together at home. Sixty adults used a mask with 630 nm red and 850 nm near-infrared, or a sham mask, for 12 weeks, with a follow-up at week 16. Crow's feet scores were significantly better than sham at 8, 12 and 16 weeks.

Why either works. A 2013 review (Avci and colleagues) notes that skin responds well to both red and near-infrared wavelengths. The photons are absorbed by chromophores in the mitochondria of skin cells, which activates signaling pathways and blood flow.

So the trials support both. They do not show that one beats the other for skin.

Is near-infrared light therapy the same as an infrared sauna?

No. Near-infrared light therapy uses LEDs at set wavelengths, around 830 to 850 nm, at a low level, and one skin trial describes its light as non-thermal. An infrared sauna is built to heat your body and make you sweat. A review of far infrared notes that specialty saunas deliver far-infrared radiation, a different band.

The two get confused because both say "infrared." They sit at different parts of the spectrum and do different jobs.

Near-infrared light therapy: low-level light aimed at the skin. No sweating. Studied for wrinkles and collagen.
Infrared sauna: heat for the whole body. You sweat, so you lose fluid and need to replace it.

The far-infrared review defines that band as 3 to 100 μm. The near-infrared in the trials above, 830 to 850 nm, is under 1 μm. Replacing fluid and sodium after sweating is well supported.

More on saunas: Infrared vs traditional sauna. How light, heat and hydration fit together: The Glow Protocol.

Myth: hydrated skin lets light penetrate deeper

It is a neat idea, and it is not what the optics research shows.

Researchers who want light to travel deeper into tissue use a technique called optical clearing. In a 2016 study on mouse skin (Guo and colleagues), an optical clearing agent improved imaging of deeper tissue. The authors attributed the improvement most likely to the agent drawing water out of the skin, along with a drop in light scattering of more than about 40.5% in the superficial layers.

That is the opposite of "more water, more light."

This does not mean you should dry your skin out before a session. That study used a chemical agent on mouse skin to improve imaging. It was not a test of red light therapy, and it says nothing about results in people.

What it does mean is that we will not claim hydration helps your device. H2Glow's role is the skin's own condition, not the light.

Which should you choose?

You rarely have to. Most masks combine a red and a near-infrared wavelength, as all three masks in our red light masks guide do.

For a face mask, look for both wavelengths stated in nanometers.
If a device offers only one, the Lee trial found each worked alone.
If you want heat and sweat, that is a sauna, not a light mask.

Is near-infrared light safe?

In the trials, LED light at these wavelengths was well tolerated. Lee 2007 reported no adverse effects. Park 2025 described its home mask as safe, well tolerated and painless. The 2013 review noted an almost complete absence of side effects.

Follow the maker's instructions on eye protection and session length. Check with your doctor first if you are pregnant, take medication, or have a skin or eye condition.

What near-infrared light does not do

It does not heat you like a sauna.
It is not proven better than red for skin. In the trial that tested both, each worked.
It does not work in days. The trials ran for weeks.
It does not treat skin conditions. See a dermatologist.
It is not helped by hydration.

Make it a Glow Protocol

Before. Start with clean, dry skin, unless your device's instructions say otherwise.
During. Follow the maker's session length and weekly schedule.
After. Go back to your usual routine: moisturizer, and sunscreen in the daytime.
Daily. Hydration is the layer underneath, every day. That is Step 0. It supports the skin's own water content. It does not make the light work better.

H2Glow is Step 0: the hydration layer underneath the routine. It does not make any device work better. See the full Glow Protocol.

Where H2Glow fits

H2Glow is Step 0: what is inside your skin before anything goes on it. Hydrated skin performs better, and by that we mean the skin's own water content, barrier and elasticity.

One stick has 17 actives, including 250 mg of sodium hyaluronate, 40 mg of rice phytoceramides, electrolytes and 1,500 mg of glycine, proline and lysine, collagen's amino acids. In a placebo-controlled trial of 40 adults, 120 mg of oral hyaluronic acid a day for 12 weeks improved outer-layer water content, water loss and elasticity. That trial did not test H2Glow, and no study has.

Frequently asked questions

Is near-infrared better than red light for skin?

Not shown. In a randomized trial, 830 nm alone, 633 nm alone and both together all reduced wrinkles and improved elasticity.

What is near-infrared light therapy?

Low-level light at wavelengths just beyond visible red, around 830 to 850 nm in skin devices. It is usually delivered by LEDs and paired with red light.

Can you see near-infrared light?

No. Red light is visible. Near-infrared is not.

Is infrared the same as red light therapy?

No. Red light therapy uses visible red light, often with near-infrared. "Infrared" on a sauna means heat, often far infrared, which is a different band.

Does near-infrared light penetrate deeper?

In computer modeling of skin, penetration depth increased with wavelength, so near-infrared reaches deeper than red. The deepest penetration calculated was about 5.4 mm.

Does drinking water help red light penetrate deeper?

No. In lab research on mouse skin, an agent that drew water out of the skin reduced light scattering. Hydration supports your skin's own condition, not the light.

What are the dangers of near-infrared light therapy?

The skin trials here reported LED light as well tolerated, with no adverse effects in one. Follow the maker's instructions, including on eye protection, and check with your doctor first if you have a condition.

Do I need both red and near-infrared?

Most masks include both. The trial that tested each alone found both worked.