Red Light Therapy for Anxiety and Depression: What It Actually Does

I want to be careful with this post. Both because I've watched people I love go through depression, including my own stretches of it, and because the friend of mine with crippling anxiety isn't a research statistic, she's someone who has had years where leaving the house was a project. So I'm not going to oversell anything here. What I'm going to do is tell you what red light therapy can plausibly do, what the research actually shows, what it can't do, and what to think about if you're considering trying it.

This is not a post that's going to tell you a panel cures depression. It's a post about a tool that affects some of the underlying biology, that might be useful for some people, and that's worth understanding properly if your standard pathway isn't working.

Red light therapy (rødlysterapi) for anxiety and depression works through several mechanisms: direct effects on brain tissue when light reaches the prefrontal cortex, modulation of the HPA axis and cortisol rhythm, improved mitochondrial energy production in neurons, and reduction of neuroinflammation. The research is early but consistent enough to take seriously, with the strongest evidence for transcranial photobiomodulation in major depressive disorder, and emerging evidence for generalised anxiety. It is not a replacement for therapy or medication if you need them. It's a tool that addresses biology those things often don't reach.

Why I Take This One Seriously

I've been close to depression in my own life and in my family. Not the version where you're a bit down for a week. The version where months go missing. Where the things you used to enjoy stop registering as enjoyable, where the morning is a thing you have to negotiate with, where you're functioning but the colour has gone out of everything.

And the friend with the anxiety. Years of it. Real, body-level, can't-get-out-of-the-car anxiety. She's tried therapy, medication, the whole standard pathway, with mixed results.

So when I look at the research on photobiomodulation and mood, I'm not looking at it the way a product seller looks at studies he wants to be excited about. I'm looking at it the way someone looks at it when the question matters personally. Does this stuff actually do anything? Where is the signal? Where is the noise?

Because if it does something, even something modest, that's worth knowing. The mental health field is not exactly drowning in good options, and a lot of what's offered doesn't work the way it's claimed to. A tool that addresses some of the biology underneath, that's safe, that's not pharmaceutical, that you can use at home, is worth looking at properly.

What's Actually Going On in the Brain

I'll try to explain this the way it makes sense to me, not the way the textbooks lay it out.

Your brain runs on energy. Massive amounts of it. The brain is around two percent of your body weight and uses around twenty percent of your total energy. That energy gets made in your mitochondria, the little power plants inside your cells, and it's made through a process that depends, among other things, on an enzyme called cytochrome c oxidase.

In depression and chronic anxiety, you tend to see reduced mitochondrial function in specific brain regions, particularly the prefrontal cortex, which is the part of the brain involved in mood regulation, emotional control, executive function. The cells aren't dead. They're underpowered. They're not making enough ATP to do their job properly. This is well-documented now in the research literature.

Red light at around 630-680nm and near-infrared light at around 800-850nm both interact with cytochrome c oxidase. When you shine the right wavelengths on tissue, the enzyme absorbs the photons and ATP production goes up. This is the basic mechanism of photobiomodulation, the same one that's at work when light helps a tendon or a joint or a wound. It's a cellular energy intervention. And applied to the head, with enough power to actually reach brain tissue, it appears to do the same thing to underpowered neurons.

Dr Michael Hamblin, who was for many years one of the leading researchers in this field at Harvard, has been arguing the case for transcranial photobiomodulation in psychiatric conditions for over a decade. There's now a body of work suggesting that the right wavelengths, at the right power, applied to the right places on the head, can produce measurable improvements in depression scores.

A 2018 randomised controlled trial by Cassano and colleagues at Massachusetts General Hospital, published in Photobiomodulation, Photomedicine, and Laser Surgery, looked at transcranial photobiomodulation in adults with major depressive disorder. They found significant reductions in depression severity in the treated group versus sham. You can read it here.

A more recent meta-analysis from 2022, published in the Journal of Affective Disorders, pooled the studies that exist on photobiomodulation for mood disorders and concluded the effect on depression is real but the evidence base needs more high-quality trials before we can be confident about exact protocols. Here it is.

That last sentence is the honest one. The effect appears to be real. The mechanisms make sense. The studies that exist are mostly small and the protocols vary. We need more research. That's where we are.

The Cortisol and HPA Axis Bit

The other place light interacts with mood is through your stress system. Your HPA axis is the hypothalamic-pituitary-adrenal axis, the system that produces cortisol and runs your stress response. In chronic anxiety and a lot of depression, this system is dysregulated. Cortisol either runs too high all day, or it loses its normal rhythm, or both.

Light timing affects this system directly. Morning bright light, ideally sunlight, produces a cortisol awakening response that sets the rhythm for the rest of the day. Lack of morning light leaves the rhythm flat or distorted. Evening bright light, particularly blue-rich light, suppresses melatonin and pushes the cortisol curve in the wrong direction.

Red light therapy interacts with this in two ways. First, near-infrared exposure on the body has been shown in some studies to modulate HPA axis function, possibly through systemic anti-inflammatory effects, possibly through direct mitochondrial effects on the cells of the adrenal glands and the brain regions that regulate them. Second, the broader practice of being aware of your light environment, which is the wider context this all sits inside, has direct effects on circadian rhythm and therefore on cortisol patterns and mood.

I'm not going to pretend the cortisol piece is fully worked out in the research. It isn't. What I will say is that I've seen the difference in myself between weeks where I do my morning light properly, get outside even briefly, manage the evening blue light, and weeks where I don't. The pattern is consistent. Mood, energy, anxiety, all run better when the light environment is right. And red light therapy fits into that broader picture rather than sitting outside it.

What Honest Use Looks Like

Right, so what does this actually mean in practice if you're someone who's struggling and wondering whether to try it?

First thing. Red light therapy is not a substitute for evidence-based mental health care. If you need a therapist, get a therapist. If your doctor has prescribed medication that's helping, keep taking it. If you're in crisis, please reach out to someone qualified to help in a crisis. I am not your therapist, your psychiatrist, or your doctor. I'm a guy who sells panels and has thought hard about this because it affects me and people I love.

What red light therapy can be is a tool you add to whatever else you're doing. The studies on transcranial photobiomodulation for depression generally use protocols where light is applied directly to the forehead, often targeting the prefrontal cortex, for sessions of around 20 to 30 minutes, several times a week. The devices used in research are specifically designed for this. Regular body panels can deliver useful photons to the head if you sit close enough, but they're not the same thing as a head-specific device.

For more general mood and anxiety support, what I've found works in my own life and what customers report is a combination of three things. Morning red light exposure on the body, often combined with getting actual sunlight on the eyes shortly after waking. Some kind of mid-day or end-of-day session for the broader mitochondrial support and circadian anchoring. And managing the evening light environment so you're not blasting yourself with blue light until midnight.

The mechanism here is partly direct, partly about restoring the rhythm of your biology that anxiety and depression both tend to disrupt. You're not just hitting your prefrontal cortex with photons. You're putting the whole light environment back into something your body was designed to live in.

The Bit Where I Get Slightly Annoyed

Almost nobody selling red light therapy in Norway talks about the dose problem for the head specifically. The brain is behind a skull. Skull is bone. Bone blocks a lot of light. The amount of light that actually reaches brain tissue when you point a panel at your forehead is a fraction of what reaches your skin, and the panels people are typically sold don't necessarily have the power to deliver therapeutic doses to the tissue depth needed for mood effects.

So when I get the messages, and I get a lot of them now, from people who bought a 100 watt panel from somewhere and have been sitting in front of it for ten minutes a day for three months and don't feel any better, the first thing I look at is whether the dose at the relevant tissue depth was ever going to be enough. Most of the time it wasn't.

I'm not saying you need a four thousand dollar specialist device to feel any benefit. I'm saying that if you're using red light therapy for mood specifically, you need to be honest about whether what you've got is actually capable of reaching the tissue, and whether the protocol you're using makes any sense for the depth you're trying to reach. This is part of what I help customers with. Message me if you want to think through your own setup, whether or not you bought the panel from me. I'd rather you got results than gave up because someone sold you something underpowered with a generic protocol sheet.

I test every panel with a spectrometer before I'll put it on the site. I've sent stuff back when the numbers didn't match the claims. If you want the longer version of why panel specs in this industry are mostly fictional, I wrote about that here.

What I'd Actually Say to Someone Struggling

If a friend told me they were dealing with depression or chronic anxiety and asked me about red light therapy, here's roughly what I'd say.

Get the standard pathway sorted first. See your GP. If therapy is available to you, do it. If medication is helping, stay on it. None of this is in competition with red light therapy.

Get your morning light right. Get outside, on your eyes, ideally within the first hour of waking. This costs nothing and the effect on mood and circadian rhythm is real and well-documented. If you do nothing else from this post, do that.

If you want to add red light therapy on top of those things, look at it as one tool in a wider approach, not the answer on its own. The effect is real for some people, modest, and depends on doing it consistently and with adequate dose. The biggest effects in the research are for transcranial application specifically, but body-based exposure helps with the broader systemic stuff.

Manage your expectations honestly. Some people respond well and notice differences within a few weeks. Some people don't notice much. The research suggests the effect is real but moderate, and individual responses vary a lot. If you try it for two months consistently and feel nothing, it might not be your tool, or your protocol might be wrong, or your panel might be underpowered. Any of those things are worth diagnosing before giving up on the modality.

If you want to talk through whether this would make sense for your situation, send me a message. You can also have a look at the red light therapy panel collection if you want to see what's available.

Where This Connects to the Rest

If you've read the seasonal affective disorder post, you'll see this is a different angle on related biology. SAD is mood that's specifically driven by seasonal light deprivation. What I'm talking about in this post is mood and anxiety that are present regardless of season, with cellular and circadian mechanisms that overlap but aren't identical. Some people have both. The interventions overlap.

The 2025 half-year research review covers some of the recent work on mood and brain effects of photobiomodulation if you want to go deeper.

This article is for educational purposes only. It is not medical advice and is not intended to diagnose, treat, cure, or prevent any condition, including depression or anxiety disorders. If you are struggling with mental health, please speak to a qualified healthcare professional. If you are in crisis, contact emergency services or a crisis line. In Norway, Mental Helse Hjelpetelefonen is 116 123. Red light therapy is not a substitute for evidence-based mental health care.

Frequently Asked Questions

Does red light therapy help with depression?

The research suggests it can help some people with depression, particularly when applied transcranially to the prefrontal cortex. Several randomised controlled trials have shown reductions in depression scores compared to sham treatment, with the best-known work coming from Dr Michael Hamblin's lab and Massachusetts General Hospital. The effect is real but moderate, the studies are mostly small, and individual response varies considerably. It works best as part of a wider approach rather than as a standalone treatment, and it's not a replacement for therapy or medication where those are indicated.

Can red light therapy help with anxiety?

Evidence specifically for generalised anxiety is more limited than for depression, but emerging. The proposed mechanisms include modulation of the HPA axis and cortisol regulation, improved mitochondrial function in brain regions involved in fear and emotional regulation, and reduction of neuroinflammation. Many people who use red light therapy for other reasons report secondary benefits in calmness and anxiety levels, which fits with the broader systemic effects of the modality on inflammation and stress physiology. As with depression, it should not replace therapy or appropriate medical care.

How long does it take to feel mood effects from red light therapy?

Most studies on transcranial photobiomodulation for depression run for at least 6 to 8 weeks, often with sessions three times per week. People who respond tend to start noticing changes somewhere in the first month, but responses vary. If you're using body-based red light therapy as part of a broader light hygiene approach, the mood effects are usually subtle and gradual, more about restored rhythm and resilience over weeks and months than dramatic shifts.

Kan rødlysterapi hjelpe mot angst og depresjon?

Ja, forskningen tyder på at fotobiomodulasjon kan ha reell effekt på humør, særlig ved transkraniell behandling rettet mot prefrontal korteks ved depresjon. Mekanismene inkluderer økt mitokondriefunksjon i hjerneregioner som er involvert i humørregulering, modulering av HPA-aksen og kortisolrytmen, og redusert nevroinflammasjon. Det er ikke en erstatning for terapi eller medisin, men kan være et nyttig tillegg som del av en bredere tilnærming. Hvis du sliter med psykisk helse, kontakt fastlege eller psykolog først.

Is red light therapy safe to use alongside antidepressants?

There are no known interactions between red light therapy and standard antidepressant medications. Light therapy works at the cellular and tissue level rather than through the pharmacological pathways that antidepressants use, so they don't compete for the same biological mechanisms. That said, if you're on prescribed medication for any mental health condition, please discuss any new intervention with the doctor who prescribed it, and never stop or adjust medication on your own based on something you read in a blog post.

References

Cassano P, Petrie SR, Mischoulon D, et al. Transcranial photobiomodulation for the treatment of major depressive disorder: the ELATED-2 pilot trial. Photobiomodulation, Photomedicine, and Laser Surgery. 2018. https://pubmed.ncbi.nlm.nih.gov/30346890/

Askalsky P, Iosifescu DV. Transcranial photobiomodulation for the management of depression: current perspectives. Neuropsychiatric Disease and Treatment. 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6592368/

Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophysics. 2017. https://pmc.ncbi.nlm.nih.gov/articles/PMC5523874/

Meta-analysis of photobiomodulation for mood disorders. Journal of Affective Disorders. 2022. https://pubmed.ncbi.nlm.nih.gov/34954409/