How Does Red Light Therapy Actually Work?

The evidence for the benefits of light therapy – or photobiomodulation – is pretty compelling. In fact, most would consider it downright convincing. Justin Strahan, Co-founder and Head of R&D for Joovv, recently documented that red light therapy really does work. But as he mentioned, it’s imperative that you choose a device that delivers the right amount of light within a specific wavelength. Remember that wavelength and energy are vitally important when using red light therapy.

Numerous studies have shown the following benefits of red light therapy when utilizing the right wavelength of light, coupled with the right amount of power,:

  • Improved skin tone and complexion
  • Enhanced muscle recovery
  • Reduced acne, rosacea, and eczema
  • Improved appearance of wrinkles, fine lines, scars, and stretch marks
  • Enhanced circulation
  • Hair regrowth including (only in areas where you had hair before) improvements in hair growth rates, hair thickness and follicle numbers
  • Reduced pain and inflammation
  • Quicker healing of wounds and injuries

Impressive list, right? But how does red light actually produce these results and what’s going on in our bodies that produces this multitude of health benefits and healing? You’re not alone if you’re asking these types of questions. Justin studied Biology and Chemistry as part of my undergraduate education and before his experience with Joovv, he asked himself these same questions.

If you’ve done some research regarding the benefits of light therapy, you’ll often see the following as the rationale for its anti-aging properties:

  • Increased circulation through the formation of new capillaries. Or, in other words, more blood and oxygen will help to deliver proper nutrients to damaged areas.
  • Enhanced activity within your lymph system, leading to enhanced detoxification and a reduction in swelling and inflammation.
  • Increased collagen production, which directly relates to the elasticity, firmness, and fullness of your skin.

This is great information. And it makes sense. But unfortunately, most articles stop there. So, we’ll try and go a step further in an effort to answer this question: How does red light therapy actually work at a cellular level?

Side note: Some of this information gets pretty nerdy. But if you bear with us, by the end of this article, I think you’ll feel a lot better about your understanding of how light therapy works at a cellular level.

Let’s Start With How Our Cells are Supposed to Function

All living things need to make Adenosine Trihosphate (ATP), usually referred to as the “energy currency of life”. ATP is a small molecule with a huge job: to provide usable energy for cells. ATP is produced through cellular respiration, which includes the following 4 steps:

  1. Glycolysis
  2. Pyruvate oxidation
  3. Citric acid (Kreb’s) cycle
  4. Oxidative phosphorylation

Most of this activity occurs within mitochondria, the “powerhouse” of the cell. For the sake of this article, we’ll focus on the last step, oxidative phosphorylation. That’s where red light therapy is believed to help the most.

Without going too deep into the science, this step of cellular respiration involves an electron transport chain. As electrons move down this chain, energy is released and used to pump protons out of a matrix, forming a gradient. Protons flow back into the matrix through an enzyme called ATP synthase, making ATP. (1,2)

So where does ATP synthase come from? Well, the enzyme cytochrome c oxidase helps oxygen bind with NADH to form the necessary hydrogen ions that produce ATP synthase. (3) If you remember anything, set your mind on this: oxygen plus NADH is a good thing when it comes to healthy cellular function.

Whew! That’s some pretty meaty information. But we warned you, right?  So before we go on, make sure you understand how a healthy cell is supposed to function. Take another look at the paragraphs above if you have to. And remember, oxygen plus NADH is good!

What Happens When Our Cells Aren’t Healthy?

When we get sick, injured, stressed, etc., mitochondria in our cells can produce nitric oxide (NO). To understand the ramification of this, let’s go back to that little enzyme, cytochrome c oxidase.

During the creation of ATP synthase, nitric oxide competes with oxygen and binds to this enzyme. This, in turn, stops the eventual production of ATP and thereby increases oxidative stress, which can lead to cellular death. (4)

So in summary, stressed cells produce nitric oxide (NO), which binds to cytochrome c oxidase and halts the production of ATP synthase. Got it?

So How Does Red Light Therapy Restore Cellular Health?

Remember, nitric oxide competes with oxygen and binds with cytochrome c oxidase, which stops the eventual production of ATP. Red and near infrared light are our little hero when it comes to nitric oxide but more on that in a second.

Now, there are different theories as to how photobiomodulation actually helps to restore normal cellular function. But the following mechanism of action is backed by some pretty solid research conducted at Harvard University.

You see, red and near infrared light (with the right wavelengths and intensity) breaks the bond between nitric oxide and cytochrome c oxidase, that is the inhibitory nitric oxide can be disassociated by photons of light most effectively in the ranges of 600-700nm (red light) and 760-940nm (near-infrared light). When nitric oxide is disassociated, this allows oxygen to bind to NADH, which restores the normal pathway for hydrogen ions to produce ATP synthase. (4) So in summary, red and near infrared light frees up cytochrome c oxidase to allow for the eventual production of ATP.  

In addition, it has been shown that there is a brief increase in reactive oxygen species (ROS) produced in the mitochondria when they absorb the photons delivered during photobiomodulation. The theory is that this burst of ROS may trigger some mitochondrial signaling pathways leading to cytoprotective, anti-oxidant and anti-apoptotic effects in the cells (5). The nitric oxide that is released by the photodissociation acts as a vasodilator as well as a dilator of lymphatic flow. Moreover nitric oxide is also a potent signaling molecule and can activate a number of beneficial cellular pathways (6). What this means is that red and near infrared light has the ability to increase circulation, capillary formation, lymphatic system movement (detoxification), and testosterone production, as well as boost fibroblast activity and collagen formation.(7)

But by breaking that bond and restoring the production of ATP, the result is normal cellular metabolism. Once cellular function is restored, the following benefits are seen as has been proven time and time again through published clinical literature:

  • Increased collagen production due to stimulated fibroblasts via the release of cytokines
  • Enhanced circulation through the formation of new capillaries
  • Improved anti-inflammatory emissions due to increased lymph system activity
  • Increased muscle recovery, peak athletic performance, and weight loss
  • Enhanced testosterone production through the stimulation of leydig cells
  • Reduced inflammation and joint pain
  • And believe it or not, a lot more!

The reason red and infrared light therapy is able to provide such a wide range of benefits, across so many organ systems, and radically different health issues is actually quite simple: The health of every organ and every cell in the body depends on the energy produced by the mitochondria in those cells. Thus, because red/NIR light therapy work to enhance mitochondrial energy production in essentially every type of cell in the body (except for the red blood cells which do not contain mitochondria), it can enhance the cellular function and health of essentially every type of cell in the body.

Why Collagen is Important for Enhanced Health

Collagen is a long-chain amino acid and the most abundant protein in the body. It’s responsible for giving skin its strength and elasticity, hair its strength, and connective tissue its ability to hold everything in place. In fact, collagen protein makes up 30% of the total protein in the body, and 70% of the protein in the skin! (8) Collagen is one of three major components of skin, the other two being elastin and glycosaminoglycans.

While collagen is beneficial to the entire body, it’s most noticeably beneficial to the skin. This is because as a person ages, the epidermic (outer layer of skin) thins and loses elasticity in a process known as elastosis. As this happens, a person tends to show more signs of aging and acquires more wrinkles. The growth of new skin cells also slows down dramatically, which contributes to dull-colored skin as the dead cells do not shed themselves as quickly. Aging skin is also much more susceptible to the development of brown spots on the face and body.

But don’t fear… by restoring normal cellular function, red light stimulates the production of collagen and is just one of the many rejuvenating benefits of red light therapy!

Summary: Red Light Therapy Enhances Cellular Performance

By helping to restore natural cellular function, there’s a good chance you’ll look and feel rejuvenated after consistent use of red light therapy.  But remember, wavelength and intensity are incredibly imperative. Make sure you choose a device that delivers red light with the correct wavelength and an optimal amount of power.


(1) Raven, P. H.; Johnson, G. B.; Mason, K. A.; Losos, J. B.; Singer, S. R. How cells harvest energy. 2014 In Biology 10th ed. AP ed. pp. 122-146. New York, NY: McGraw-Hill.

(2) Reece, J. B.; Urry, L. A.; Cain, M. L.; Wasserman, S. A.; Minorsky, P. V; Jackson, R. B. Cellular respiration and fermentation. In Campbell Biology. 2011 10th ed. pp. 162-184. San Francisco, CA: Pearson.

(3) Yoshikawa, Shinya Shimada, Atsuhiro; Shinzawa-Itoh, Kyoko. 2015 Chapter 4 Respiratory Conservation of Energy with Dioxygen: Cytochrome c Oxidase. In Peter M.H. Kroneck and Martha E. Sosa Torres. Sustaining Life on Planet Earth: Metalloenzymes Mastering Dioxygen and Other Chewy Gases. Metal Ions in Life Sciences 15. Springer. pp. 89–130.Huang, Ying-Ying; Chen, Aaron C.-H.; Carroll, James D.; Hamblin, Michael R. Biphasic dose response in low level light therapy. 2009 Nonlinearity in Biology, Toxicology, and Medicine.


(5) G.B. Waypa, K.A. Smith, P.T. Schumacker O2 sensing, mitochondria and ROS signaling: the fog is lifting Mol. Asp. Med., 47-48 (2016), pp. 76-89

(6) Y. Zhao, P.M. Vanhoutte, S.W. Leung Vascular nitric oxide: beyond eNOS J. Pharmacol. Sci., 129 (2015), pp. 83-94

(7) Zastrow L, Groth N, Klein F, et al. The missing link–light-induced (280–1,600 nm) free radical formation in human skin. Skin Pharmacol Physiol. 2009;22(1);31-44.

(8) Di Lullo, Gloria A.; Sweeney, Shawn M.; Körkkö, Jarmo; Ala-Kokko, Leena & San Antonio, James D. (2002). Mapping the Ligand-binding Sites and Disease-associated Mutations on the Most Abundant Protein in the Human, Type I Collage.. J. Biol. Chem. 277 (6): 4223–4231

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