Red Light vs. Infrared vs. Near-Infrared: Clearing Up the Confusion Bl

Red Light vs. Infrared vs. Near-Infrared Blog

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Last updated: April 2025

If you’ve spent time researching red light therapy, you’ve undoubtedly seen the terms red light, near-infrared (NIR), and infrared (IR) therapy used interchangeably.

However, these terms are for different sets of wavelengths that have varying therapeutic benefits.

Here’s what you need to know about these wavelengths: what they are, their benefits, when to use each one, and how they can work together to improve your health and wellbeing.

This article is for you if you’ve wondered:

What are infrared and near-infrared lights?
Red light therapy vs. infrared: Are they the same?
How do near-infrared and infrared therapy compare to red light?
Is one better than another?
When should I use red, infrared, or near-infrared light?

1. The Wavelengths of Red Light

The term 'red light therapy' often includes wavelengths in both the visible spectrum of light and the invisible spectrum of light. The visible spectrum is from 630 to 660 nanometers, whereas the invisible infrared spectrum is from 810 to 850 nanomeneters. This is considered near-infrared.

What all these wavelengths have in common is that they fall into what is known as the 'therapeutic window.' This means they have the power to treat specific conditions.

'Red light therapy' is also referred to as 'low-level light therapy' (LLLT) and 'photobiomodulation' (PBM).

Technically, both NIR and IR light therapy fall into the same category of invisible infrared wavelengths in the electromagnetic spectrum.

You may also see the acronym LLLT in reference to low-level laser therapy. In this treatment, the wavelengths and benefits are the same but the delivery is different. As the name implies, low-level laser therapy uses low-level lasers, whereas red light therapy utilizes red LED lights.

A large body of scientific research suggests wavelengths in the red/NIR electromagnetic scale can safely deliver a variety of health benefits, without adverse effects.

So what's the difference between the wavelengths?

In many respects, red, NIR, and IR wavelengths provide similar health benefits including pain relief as well as some surprising benefits like weight loss.

What sets red light apart from near-infrared is the depth to which the light photons can absorb into your body’s tissues.

NIR light is closely related to red light in that it doesn’t cause heating of the body, which occurs in wavelengths in the mid to far-infrared light spectrum.

NIR waves of up to 850nm are used in red light therapy systems. IR waves are most commonly used either in clinical applications or in infrared saunas.

2. Red Light Therapy vs. Near-Infrared

As you increase the wavelength of light, you also increase how deep the light penetrates into the body.

Red wavelengths benefit the skin and systems within the skin tissue, including the circulatory system, peripheral nervous system, and hair follicles.

The longer wavelengths of NIR light reach beneath the skin to cells deep in your body, including muscles, joints, and bones.

3. The Benefits of the Red Light Spectrum (630–660nm)

The visible red light spectrum primarily benefits skin conditions. It is best known for its anti-aging properties, such as fine lines and wrinkles, even skin tone, and photoaging, skin wound healing, stretch marks, and hair loss.

Example: Red Light for Skin Health

Multiple studies have shown the benefits of red light for skin health, and that it has no adverse effects.

A 2014 controlled trial showed promise for the use of red light to reduce wrinkles and increase collagen protein synthesis. You can see photos of the results in the red light therapy skin trial results.

Other potential health benefits of red light include:

Stimulating hair regrowth in both men and women
Reducing acne inflammation and breakouts
Reduction of fine lines, sagging skin, sun damage, and wrinkles
Psoriasis treatment
Healing of non-melanoma skin cancers
Accelerated wound healing
Reduction of inflammation due to pleurisy
Reduction of neuropathic pain (sciatic nerve pain)
Reduction of post-injury swelling and inflammation
Reduction of training fatigue and faster athletic recovery
Note: A powerful LED light therapy device will ensure the maximum possible penetration depth for any wavelength.

4. The Benefits of the Near-Infrared Spectrum (810–850nm)

As previously mentioned, NIR wavelengths from 810 to 850nm can penetrate deeper than red light, including connective tissue and bone. Most notably, these wavelengths can treat the brain.

Example: Near-Infrared Therapy for Brain Health

In a 2016 article, world-renowned red light expert Michael Hamblin discusses the exciting potential of red/NIR light therapy for treating myriad disorders of the brain.

He writes: “Many investigators believe that PBM for brain disorders will become one of the most important medical applications of light therapy in the coming years and decades.”

That is encouraging, although more studies are needed on the effects of NIR light and brain health. Anyone suffering from a brain injury or neurological disorder should always receive treatment as prescribed by a medical professional.

Other potential health benefits of NIR light include:

Improved muscle healing and accelerated recovery
Improved recovery from strokes
Improved recovery from neurological damage and from traumatic brain injury
Improvement of psychiatric disorders including anxiety and depression
Reduced recovery and accelerated healing following plastic surgery
Accelerated healing and reduced infection
Improved bone repair and growth
Accelerated return to athletic activity after injury
Nerve cells in particular appear to respond well to infrared light energy. Most studies reference infrared waves in the 800 to 900nm range.

Therefore, infrared light in the NIR spectrum could be a potentially effective therapy for Alzheimer’s, Parkinson’s, and other neurodegenerative disorders

Another potential use for NIR light is treating neuropathy. This is exciting news for those who suffer from diabetes or anyone who has nerve damage in their hands, feet, or other parts of the body.

5. Benefits of Infrared Therapy (900+nm)

Beyond 850nm, infrared waves penetrate even deeper. Infrared light therapy is most commonly used in infrared saunas, which typically use wavelengths in the 1000nm range.

What’s really interesting is that the human body reacts differently to these longer wavelengths. Instead of light, the body perceives them as infrared heat.

When infrared waves come in contact with your body’s tissues, it causes the molecules to vibrate, which produces heat and causes a rise in body temperature.

This infrared heat effect can stimulate local blood circulation and reduce muscle tension. This is one of the reasons infrared saunas have become so popular worldwide.

Used with caution, infrared therapy is seen as a potentially effective treatment for:

Pain relief
Cancer, when used as photoimmunotherapy
Reducing the side effects of chemotherapy
Accelerating healing of the brain after injury
We recommend that potential users of infrared saunas also check with their doctor before seeking treatment.

Infrared light therapy (over 900nm) has the deepest penetration along with positive health effects, but should be used with caution to prevent thermal damage to the body’s cells.

6. Red vs. Near-Infrared vs. Infrared Therapy … Which Is Best?

The greatest benefits could come from a combination of red and NIR light.

Here’s why:

If you’re looking for a device to provide skin rejuvenating benefits or to treat chronic skin disorders like eczema or psoriasis, you may find red light to be enough.

Nonetheless, we recommend a combination of red and NIR light. This has been clinically proven to stimulate positive biological processes in the body, including:

Enhancing cellular functioning by stimulating energy production within the cells
Stimulating collagen and elastin production
Improving blood flow
Reducing inflammation

Among the many potential benefits of light therapy using red/NIR wavelengths, these four benefits stand out as the keys to supporting the body’s self-healing mechanisms.

While red light can do that at the skin level, if a condition is caused by inflammation deeper in the body, you’ll need the deeper penetration of NIR light to reduce the inflammation.

When used together, they work synergistically to target not only skin cells, but muscle tissue, organ tissue, connective tissue, brain tissue, and bone tissue, as well as increased blood flow.