Red Light Therapy: What It Actually Does and How to Use It as a Practitioner
Red light therapy has become increasingly popular over the last few years.
You’ve probably seen it marketed as a solution for everything from pain to recovery to skin health. Like most things that gain traction quickly, it tends to get oversimplified or overhyped. So the better question is not “does it work?” but rather, what does it actually do, and how should we use it?
I spent time reviewing clinical research on photobiomodulation, specifically looking at how red and near-infrared light affect pain, inflammation, and tissue healing in musculoskeletal conditions. What follows is what actually matters for you as a practitioner.
What Red Light Therapy Is Doing at the Tissue Level
Photobiomodulation is the use of light to influence biological processes. The wavelengths that seem to matter most fall between roughly 630nm and 950nm (Tsai & Hambin, 2017). This range appears to be where light can penetrate tissue and interact with cells in a meaningful way. The exact mechanisms are still being studied, but there are a few consistent theories.
One is that light energy is absorbed by cells and influences mitochondrial activity, which may increase ATP production. In simpler terms, it may help cells produce more energy.
Another is that it affects nerve cells directly, particularly those involved in pain signaling. There is evidence suggesting that photobiomodulation can influence the sodium-potassium pump in nociceptive neurons, which may reduce the transmission of pain signals (De Oliveira et al., 2022; Dompe et al., 2020).
It may also influence inflammatory pathways and cellular signaling involved in tissue repair (Dompe et al., 2020).
So, we may not have a perfectly defined mechanism, but we do have a consistent theme. This is a modality that can influence how cells behave, how pain is perceived, and how tissue responds to injury.
What the Research Shows About Pain
This is where the evidence is the strongest.
Across multiple clinical trials, red light therapy consistently shows a reduction in pain across a variety of conditions. This includes joint disorders, tendon injuries, arthritis, fibromyalgia, and lower back pain. The effect is not isolated to one condition, which suggests that the mechanism is not purely structural. It is likely neurological and biochemical.
(Borges et al., 2018; De Oliveira et al., 2022; Elnaggar et al., 2021; Langella et al., 2018; Lima et al., 2022; Lin et al., 2020; Santiago et al., 2022; Stausholm et al., 2022; Takla & Rezk, 2019)
Another important point is that red light therapy tends to work well as an adjunct, not a standalone solution. When combined with other interventions like strength training or physical therapy, outcomes tend to improve more than when either intervention is used alone (Lima et al., 2022; Stausholm et al., 2022; Takla & Rezk, 2019) This matters for how you integrate it into your sessions.
What We Know About Inflammation
There is less research here, but what we do have is promising.
In one study looking at post-surgical patients, red light therapy reduced specific inflammatory markers, including tumor necrosis factor alpha and interleukin-8 (Langella et al., 2018). This suggests that photobiomodulation can influence the inflammatory response, particularly in acute situations. That is relevant because inflammation is not inherently bad. It is part of the healing process. But excessive or prolonged inflammation can delay recovery and increase pain sensitivity. If we can modulate that response, we may be able to create a more favorable environment for healing.
Effects on Healing and Tissue Quality
There is also evidence that red light therapy can improve aspects of tissue healing.
In studies examining wound healing, treated tissue demonstrated better overall quality during the healing process (Ramos et al., 2018). This does not necessarily mean that healing happens dramatically faster, but it may mean that the tissue heals in a way that is more organized and functionally useful. Better tissue quality can influence long-term outcomes, especially when it comes to mobility, sensitivity, and function.
What This Means for Manual Therapists
This is where context matters most. Red light therapy is not a replacement for manual therapy, and it is not a replacement for exercise. It is an input.
Specifically, it is an input that can:
Reduce pain
Potentially modulate inflammation
Improve the environment for tissue healing
That makes it useful, but only when used intentionally. If you reduce someone’s pain, you have created an opportunity. That opportunity should be used to improve movement, restore function, and build capacity. If you do not follow it with anything, the system will likely return to its previous state. This is consistent with how we utilize manual therapy in the TheraPro Method.
Where It Fits in a Treatment Plan
A more useful way to think about red light therapy is as a supporting tool.
You might use it:
At the beginning of a session to reduce pain and improve tolerance to treatment
After manual therapy to support recovery
As a home-based intervention to increase treatment frequency without increasing physical load
Because many of these devices are relatively inexpensive and accessible, they can also give clients something actionable to do outside of the session. That can be valuable, especially when you are trying to influence what happens during the other 23 hours of the day.
Limitations and Considerations
There are still gaps in the research. We do not have complete clarity on:
Optimal dosing
Duration of treatment
Differences between LED and laser devices
Long-term effects
There is also variability in how these studies are conducted, which makes it difficult to standardize protocols. The results are promising, but they should be applied with some level of clinical reasoning rather than blind adoption.
Final Thoughts
Red light therapy is not a miracle intervention, but it is not meaningless either. The research supports its ability to reduce pain, influence inflammation, and support tissue healing.
For practitioners, that makes it a useful tool, especially when integrated into a system that includes manual therapy, movement, and progressive loading. Like anything, its value is not in the tool itself, but in how and when you use it. That’s where your clinical reasoning matters most.
References:
Borges, R. M. M., Cardoso, D. S., Flores, B. C., da Luz, R. D., Machado, C. R., Cerveira, G. P., ... & Dohnert, M. B. (2018). Effects of different photobiomodulation dosimetries on temporomandibular dysfunction: a randomized, double-blind, placebo-controlled clinical trial. Lasers in medical science, 33, 1859-1866. https://doi.org/10.1007/s10103-018-2533-6
De Oliveira, M. F., Johnson, D. S., Demchak, T., Tomazoni, S. S., & Ernesto, C. (2022). Low-intensity LASER and LED (photobiomodulation therapy) for pain control of the most common musculoskeletal conditions. European journal of physical and rehabilitation medicine, 58(2), 282. https://doi.org/10.23736/S1973-9087.21.07236-1
De Oliveira, P. R., Arrebola, L. S., Stefani, K. C., & Pinfildi, C. E. (2022). Photobiomodulation associated with conservative treatment for Achilles tendon rupture: A double-blind, superiority, randomized controlled trial. Archives of Rehabilitation Research and Clinical Translation, 4(4). https://doi.org/10.1016/j.arrct.2022.100219
Dompe, C., Moncrieff, L., Matys, J., Grzech-Leśniak, K., Kocherova, I., Bryja, A., ... & Dyszkiewicz-Konwińska, M. (2020). Photobiomodulation—underlying mechanism and clinical applications. Journal of clinical medicine, 9(6), 1724. https://doi.org/10.3390/jcm9061724
Elnaggar, R. K., Mahmoud, W. S., Abdelbasset, W. K., Alqahtani, B. A., Alrawaili, S. M., & Elfakharany, M. S. (2021). Low-energy laser therapy application on knee joints as an auxiliary treatment in patients with polyarticular juvenile idiopathic arthritis: a dual-arm randomized clinical trial. Lasers in Medical Science, 1-10. https://doi.org/10.1007/s10103-021-03427-6
Langella, L. G., Casalechi, H. L., Tomazoni, S. S., Johnson, D. S., Albertini, R., Pallotta, R. C., ... & Leal-Junior, E. C. P. (2018). Photobiomodulation therapy (PBMT) on acute pain and inflammation in patients who underwent total hip arthroplasty—a randomized, triple-blind, placebo-controlled clinical trial. Lasers in medical science, 33, 1933-1940. https://doi.org/10.1007/s10103-018-2558-x
Lima, G. E. G., Lopes-Martins, R. A. B., Magalhães, D. S. F., Bovareto, A. M., Teixeira, L. C., Rocha, M. S. T., ... & Baptista, A. (2022). Photobiomodulation Therapy Using Infrared (808 nm) Low Level Laser Therapy Associated with Strength Training in Knee Osteoarthritis: A Randomized placebo-controlled clinical trial. Manual Therapy, Posturology & Rehabilitation Journal, 20, 1-10. https://doi.org/10.17784/mtprehabjournal.2022.20.1271
Lin, Y. P., Su, Y. H., Chin, S. F., Chou, Y. C., & Chia, W. T. (2020). Light-emitting diode photobiomodulation therapy for non-specific low back pain in working nurses: A single-center, double-blind, prospective, randomized controlled trial. Medicine, 99(32). https://doi.org/10.1097/MD.0000000000021611
Ramos, R. M., Burland, M., Silva, J. B., Burman, L. M., Gelain, M. S., Debom, L. M., ... & Valmier, J. (2019). Photobiomodulation improved the first stages of wound healing process after abdominoplasty: an experimental, double-blinded, non-randomized clinical trial. Aesthetic plastic surgery, 43, 147-154. https://doi.org/10.1007/s00266-018-1271-2
Stausholm, M. B., Naterstad, I. F., Alfredo, P. P., Couppé, C., Fersum, K. V., Leal-Junior, E. C. P., ... & Bjordal, J. M. (2022). Short-and long-term effectiveness of low-level laser therapy combined with strength training in knee osteoarthritis: A randomized placebo-controlled trial. Journal of Clinical Medicine, 11(12), 3446. https://doi.org/10.3390/jcm11123446
Takla, M. K. N., & Rezk, S. S. R. A. (2019). Clinical effectiveness of multi-wavelength photobiomodulation therapy as an adjunct to extracorporeal shock wave therapy in the management of plantar fasciitis: a randomized controlled trial. Lasers in Medical Science, 34, 583-593. https://doi.org/10.1007/s10103-018-2632-4
Tsai, S. R., & Hamblin, M. R. (2017). Biological effects and medical applications of infrared radiation. Journal of photochemistry and photobiology. B, Biology, 170, 197–207. https://doi.org/10.1016/j.jphotobiol.2017.04.014