🛑 Weekly Light Therapy Newsletter: Finding The Optimal Dose For Spinal Cord Injuries Dilemma & More

This week, we're covering a very complex review (that integrates all earlier evidence) on spinal cord injuries that just came out. At the end of the newsletter, we're telling you what we'd do if we were affected by this (potentially horrible) injury, even in the absence of perfect evidence!

We're also giving you all of our latest articles. Let's go:

Weekly Study: Red Light Therapy For Spinal Cord Injury Review

This new study just came out in November 2025. It's an exciting topic as the issue hits so many people and can be life-changing if you're negatively affected. One reason here light therapy is so promising is because it may give people and edge in a condition that's very hard to target generally.

We've created articles on the topic of nerve health in the past, such as on neuropathy:

But let's return to the study. You can check a free full text of the study HERE.

The researchers start by saying that spinal cord injuries have secondary effects. These effects include inflammation, excitotoxicity due to cell damage, oxidative stress (such as "reactive oxygen species", which is harmful in excess, programmed cell death (apoptosis) which leads to cell loss, scars in the nerve tissue, destruction of the myelin sheath (which increases nerve conductivity speed) and more.

What the informed reader can immediately see, is that many of these aspects are affected by light therapy. However, in their review - as often is the case - the researchers immediately mention that we don't have standardized protocols yet. These protocols thus need to be developed.

Spinal cord injuries are super important because they may lead to complete loss of nervous system control below a certain part of the spine. So, a spinal cord injury (esp if complete) is far more damaging in the neck than lower back, as many biological processes under the neck would be affected.

But let's go back to the topic of light therapy. Here, the researchers write that:

"[Red light] therapy is an emerging field that holds potential for [spinal cord injury] repair due to its modulatory effects on key aspects of the secondary cascade [, which are the effects that happen in hours, days, weeks, after a spinal cord injury]. But as emphasized here, comparisons between experimental studies are difficult due to the use of different injury models, insufficient information on [red light therapy] parameters, and sometimes a lack of controls. Other variables include the nature of the emitting device, and the power density and dose used relative to distance from the injury site. "

So we're back to the classic topic of dosing and the lack of studies. Then, there's the complexity that different wavelengths have different effects, and that you can't perfectly use animal studies as animals are so different from humans in terms of their nervous system. And, spinal cord injuries develop quickly over the course of hours, days, and weeks, making it a treatment that may work on day 1 after the injury different than a treatment on day 30, for instance.

Nevertheless, the researchers state that one protocol right now, has great outcomes, compared to others - even in the few human studies available right now:

When using red light hterapy, the"parameters applied transcutaneously (i) 15,789 J/cm² (30 J) of 589 nm, (ii) 60 J/cm² (11.7 J) of 660 nm/63 J/cm² (472 J) of 670 nm, (iii) 1500 J/cm² (450 J) of 810 nm (~90 J/cm², 27 J), and directly to the cord (iv) 1800 J/cm² (540 J) of 810 nm appear to result in more consistent and corroborative outcomes than the other protocols in this comparative analysis"

These power outputs are quite high at specific locations. In this case, we strongly recommend treatment with a medical professional who specializes in light therapy, even though such professionals may still be hard to find. Nevertheless, the researchers are still optimistic that light therapy can have very positive effects for spinal cord injuries, even though it's hard to find the optimal dosing/treatment pattern. Here are some of the suggestions the authors give for optimizing this process:

Get better measurement tool of how different wavelengths and power outputs of light affect different structures of the spinal cord. The spinal cord is extremely complex, physiologically, and not all tissues are affected the same way.
Include more human research, as current studies are mostly based on animals. Even there, with animals, we don't have perfect/universal methodology. Then, later on, higher-quality human studies need to be developed, to understand dosing for the spinal cord

What is clear is that you'll need to apply light therapy pretty quickly after the injury, as many of the processes after the injury have already set in with days. So, if you wait a month, most of the potential gains may already have been prevented. This process then, would intervene through many different mechanisms, such as oxidative stress, inflammation, mitochondrial support, etc, and counteract most of the horrible effects that happen after a spinal cord injury.

For us, the review (that integrates previous research on spinal cord injuries) showcases how difficult finding perfect light therapy dosing is. We'll keep following these developments for you in the coming years!

Last, question, what's the typical takeaway here? What would I do, if I had a spinal cord injury tomorrow? I'd prob take a handheld device, apply it to the area affected, for a more conservative dose of 40-50 J/cm2, five days a week for the next 6 months. I know we don't have perfect data/information/guidelines here, but the risk of not using light therapy in this case is far bigger in my opinion than using it slightly incorrectly. The review above doesn't show any truly harmful side effects, but instead, focuses more on the incorrect dose that's applied.