Red Light Therapy for Hormonal Balance: Thyroid, Menstrual, and Testosterone Health
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Red Light Therapy and Hormonal Balance
Tired for no reason. Weight creeping up even though nothing changed in what you eat. Mood swings that feel out of proportion. Periods all over the place. A libido that's gone quiet. Any of that sound familiar?
Hormonal imbalance is one of those things that can look like a hundred different problems until someone actually joins the dots. And the dot that almost nobody joins - not the GP, not the endocrinologist, not even most nutritionists - is the light environment you're living in and what it's doing to the cellular machinery your hormonal system depends on.
Red and near-infrared light therapy (rødlysterapi) may support hormonal health across several different systems - thyroid, reproductive, testosterone - by improving mitochondrial function in the hormone-producing glands and tissues that rely on that energy to do their jobs. This is not a cure for hormonal conditions. But the mechanisms are real, the research is growing, and the connection to light is one I've been paying close attention to for years.
Why Hormones and Mitochondria Are the Same Conversation
Before getting into the specifics, this bit is worth understanding properly because it changes how you think about everything else.
Hormone-producing glands - your thyroid, your ovaries, your testes, your adrenal glands - are among the most metabolically demanding tissue in your body. The process of synthesising hormones from raw materials is genuinely energy intensive. It requires ATP, the cellular energy currency your mitochondria produce. When mitochondria are working well, your glands have the fuel to do their jobs. When mitochondria are impaired - through chronic stress, inflammation, nutrient deficiency, or a light environment that doesn't give them the activation signals they need - hormone production suffers. Not because anything is fundamentally broken. Because the engine is running out of fuel.
This is the framework that makes red light therapy relevant to hormonal health. Cytochrome c oxidase, the enzyme in your mitochondria that absorbs red and near-infrared light and responds to it, is present in essentially every hormonally active cell in your body. When you give it the light signal it's built to respond to, energy production goes up across the board. The glands that were running at 70% capacity start getting closer to 100%.
Dr. Jack Kruse has been making this case in terms of quantum biology for years - that the hormone system is fundamentally a light-regulated system, and that disconnecting from natural light cycles is one of the most underappreciated drivers of the hormonal dysfunction epidemic we're now swimming in. I don't agree with every conclusion he reaches, but on the core mechanism he's pointing at something real.
Does that change how you're thinking about the problem? Because it changed how I think about it.
The Thyroid
The thyroid research is the most developed of the three areas I'm covering here, so let's start there.
A Brazilian research group led by Dr. Danilo Biccas Höfling spent a decade studying photobiomodulation applied directly to the thyroid area in patients with Hashimoto's-induced hypothyroidism. Randomised trial, 43 patients, proper placebo control. The group receiving the light treatment required significantly lower doses of levothyroxine after the trial. Thyroid tissue examined by ultrasound showed improved structure, volume, and blood supply. And then - this is the part that genuinely impressed me - they followed those same patients up six years later and the benefits had held. Six years on, still needing less medication. No safety signals. Study here: https://pmc.ncbi.nlm.nih.gov/articles/PMC6247385/
The mechanism makes sense once you understand how Hashimoto's actually works. Your immune system is attacking the gland. The inflammatory cytokines - TNF-alpha and interferon-gamma mainly - are damaging thyroid cells and impairing their function. Photobiomodulation reduces these inflammatory markers in the gland, improves blood flow to the tissue, and restores mitochondrial function in the thyroid cells themselves. The gland is getting the conditions it needs to actually recover rather than just being continuously damaged.
If you have Hashimoto's and you're considering this, please don't adjust your levothyroxine on your own. Some people in the research did reduce their dose over time but under medical supervision with regular blood testing. Work with your doctor. Let the bloods guide it.
Women's Hormonal Health, PCOS and Fertility
This is the area where I want to be careful to be honest about the state of the evidence, because there's a lot of overclaiming in this space.
The animal research on ovarian function and photobiomodulation is genuinely promising. A PubMed study on PCOS-induced rats found that laser therapy three times per week increased healthy ovarian follicles, raised LH levels, and reduced ovarian cysts. You can read it here: https://pubmed.ncbi.nlm.nih.gov/30897401/
The human research is still emerging. A 2024 prospective case series published in the Journal of Clinical Medicine examined multiwavelength red and near-infrared photobiomodulation in women with complex infertility profiles including PCOS, endometriosis and low ovarian reserve. The result: successful pregnancies and healthy births in women who had previously failed IVF. One case report with longer follow-up showed a healthy baby born in June 2024 after a full-term pregnancy. Full study: https://pmc.ncbi.nlm.nih.gov/articles/PMC11642705/
One case series isn't definitive. I'll be the first to say that. But the mechanism - improving mitochondrial function in ovarian tissue, reducing local inflammation, improving blood supply to the reproductive organs - is the same mechanism we see working in other tissue types, and the preliminary human results are encouraging enough to take seriously.
For menstrual pain specifically, the anti-inflammatory and circulation-improving effects of red and near-infrared light applied to the lower abdomen are well supported in the broader PBM literature. If your periods are genuinely difficult and you're looking for something that addresses root-level inflammation rather than just masking the symptoms, this is worth exploring as a complementary approach.
Testosterone
Men come to me about this more than they used to. And for a while I gave quite a cautious answer. I'm still cautious, but the honest answer is more interesting than "we don't know yet."
The biological case is solid. Leydig cells - the cells in the testes that produce testosterone - are exceptionally rich in mitochondria. Testosterone synthesis from cholesterol is energy-intensive. It requires ATP. If the mitochondria in those cells are compromised, the cells may prioritise basic survival over specialised hormone production. This isn't a theory - it's how mitochondria behave under stress in general.
The 2013 study by Ahn, Kim and Rhee published in Biomedical Research treated male rats with a 670nm laser and found a significant increase in serum testosterone levels without histopathological side effects. The authors concluded low-level laser therapy might represent an alternative to conventional testosterone replacement. Study here: https://pubmed.ncbi.nlm.nih.gov/23471553/ (search Ahn Rhee Biomedical Research 2013 LLLT testosterone)
The human clinical evidence is still limited - I want to be straight about that. The animal data is clear, the mechanism is coherent, the small human reports are encouraging. But we don't yet have a large, rigorous, placebo-controlled trial in humans showing a specific percentage increase. Anyone claiming very precise numbers at this stage is overstating what we know.
What I will say is this: if you're a man in your 40s or 50s whose testosterone is trending downward, whose mitochondrial function has been compromised by years of poor sleep, stress, artificial light environments and not enough time outside - which describes most men living modern lives at northern latitudes - then the Leydig cell argument for red light therapy is worth taking seriously. The downside risk is essentially zero. The upside, if the mechanism holds in humans the way it does in animal models, is meaningful.
The Light Environment Underneath All of This
There's a layer to this conversation that I think matters more than any single protocol or study.
Your entire hormonal system is regulated at the top by the hypothalamus and pituitary gland. These structures are circadian organs - they respond to light and dark cycles to time the release of every downstream hormone in your body. TSH, LH, FSH, cortisol, melatonin, DHEA - all of them follow rhythms that are set by your light environment. When that light environment is consistently wrong - too much blue light at night, not enough red and near-infrared in the morning, months in Norway where the solar spectrum is heavily attenuated - those pulsing patterns become irregular.
Regular hormonal dysfunction is a systems-level problem that gets treated as individual gland problems. Fix the thyroid. Manage the PCOS. Address the testosterone. But the disrupted light environment that's affecting the signalling to all of them simultaneously? That barely gets a mention.
Red light therapy in the morning is one part of addressing this. Circadian-friendly lighting in the evenings is another. Blue light glasses after dark to protect melatonin production, which itself has downstream effects on every other hormone in the system. None of these are silver bullets individually. Together they start to look like a coherent approach to a problem that is genuinely environmental in a significant part.
For circadian lighting that supports rather than disrupts your evening hormonal cascade: https://lighttherapy.no/collections/circadian-and-sleep-healthy-lighting
For blue light glasses: https://lighttherapy.no/collections/blue-light-blockers
For red light panels: https://lighttherapy.no/collections/red-light-panels
A Note on the Bespoke Guide
When people buy a panel from me, they get a personalised protocol guide - not "use it for 5-20 minutes, 3-7 times a week." That advice is useless. A knee joint needs different irradiance, duration and distance than a thyroid or a reproductive organ. The guide covers what the research suggests for specific targets, accounting for tissue depth, skin type, and what you're actually trying to achieve. Because the difference between using a panel well and using it wrong isn't huge but it's real, and I'd rather you get the most out of it.
This post is educational. None of it is medical advice. If you have diagnosed hormonal conditions, work with your doctor. Never adjust thyroid or hormone medication without medical supervision.
FAQ
Can red light therapy help with hormonal imbalance? Research suggests that red and near-infrared light can support hormonal health by improving mitochondrial function in hormone-producing glands and tissues. The thyroid, ovaries, and testes all depend on adequate ATP production to synthesise hormones effectively. A decade of Brazilian research on Hashimoto's thyroiditis showed patients needing significantly less thyroid medication after photobiomodulation treatment. For testosterone, the animal research is strong and the mechanism is well-understood. For female reproductive health, human case series are now showing promising fertility outcomes. In all cases this is supportive and complementary - not a replacement for medical treatment.
Does red light therapy help PCOS? Animal research shows photobiomodulation can increase healthy ovarian follicles, regulate LH levels, and reduce ovarian cysts in PCOS models. A 2024 human case series found successful pregnancies in women with PCOS, endometriosis and low ovarian reserve following PBM treatment. The mechanism - improving mitochondrial function in ovarian tissue, reducing local inflammation, improving reproductive blood flow - is consistent with what we see in other tissue types. The human evidence is still emerging but pointing in the right direction.
Can red light therapy increase testosterone? The biological case is strong. Leydig cells are rich in mitochondria and testosterone synthesis requires ATP - so improving mitochondrial function in those cells should support testosterone production. Animal studies confirm measurable testosterone increases from red light exposure. Human clinical evidence is still limited and anyone quoting very precise percentages at this stage is overstating what the research has confirmed. But the mechanism is coherent and the downside risk is essentially nil.
Kan rødlysterapi hjelpe med hormonbalanse? Forskning tyder på at rødt og nær-infrarødt lys kan støtte hormonhelse ved å forbedre mitokondriel funksjon i hormomproduserende kjertler og vev. Skjoldbruskkjertelen, eggstokkene og testiklene er alle avhengige av tilstrekkelig ATP-produksjon for å syntetisere hormoner effektivt. Et tiår med brasiliansk forskning på Hashimotos tyreoiditt viste at pasienter trengte betydelig mindre skjoldbruskkjertelmedisin etter fotobiomodulasjon. Dette er støttende og komplementær behandling - ikke erstatning for medisinsk behandling.
How often should I use red light therapy for hormonal support? Daily or near-daily use over months is what the research supports for hormonal effects. This isn't an acute treatment. The thyroid research used ten sessions over five weeks with benefits sustained at six-year follow-up. For testosterone and reproductive health, consistent daily sessions over 8-12 weeks is a reasonable minimum before expecting to see measurable changes. Position the panel to deliver near-infrared to the relevant area - neck for thyroid, lower abdomen for reproductive organs - for 10-15 minutes per session at moderate distance.
Is red light therapy safe for use near the thyroid or reproductive organs? The long-term Brazilian thyroid research followed patients for six years and found no safety signals - no increased nodule rates, no adverse effects. Near-infrared light is non-ionising and fundamentally different in risk profile from ionising radiation like X-rays. Multiple studies on reproductive tissue show no DNA damage to sperm at relevant light doses. As always, if you have active cancer or are pregnant, discuss with your doctor first. Otherwise the safety profile of near-infrared photobiomodulation is well established.
References: Höfling et al. 2013/2018 - LLLT in autoimmune thyroiditis, RCT and 6-year follow-up: https://pmc.ncbi.nlm.nih.gov/articles/PMC6247385/
Photobiomodulation for PCOS-induced rats and ovarian activity: https://pubmed.ncbi.nlm.nih.gov/30897401/
Phypers et al. 2024 -Multiwavelength PBM for female fertility outcomes: https://pmc.ncbi.nlm.nih.gov/articles/PMC11642705/
Ahn, Kim, Rhee 2013 - LLLT effects on testosterone in rats. Biomedical Research 24(1):28-32
Related: https://lighttherapy.no/blogs/english/red-light-therapy-thyroid-hashimotos-norway Related: https://lighttherapy.no/blogs/english/red-light-therapy-weight-loss-metabolism-norway