Red Light Therapy for Thyroid Health: New 2026 Study

Can red light therapy help with thyroid health? A 2026 study published in the journal Antioxidants suggests it might, at least for women in the early stages of Hashimoto's thyroiditis. In a trial of 50 women, those who had thyroid-directed red and near-infrared light (photobiomodulation) saw their glutathione rise, their thyroid antibodies fall and their thyroid get smaller over three months, while a comparison group taking selenium and vitamin D did not see the same changes. It was a small, non-randomised study, so it's a promising signal rather than proof, and red light therapy for thyroid health is something to talk through with your doctor alongside your treatment, never instead of it.

We all know someone like this. Perhaps it's you. The kind of tired that a full night's sleep doesn't touch. Cold hands. That fog that rolls in around two in the afternoon. The jumper you're still wearing in June. And then someone tells you your thyroid is fine, again. Or you've never had it checked, and you've put it down to getting older.

I'm writing this on a Thursday evening in October, properly dark by half-past six here in Drammen, with a glass of kefir and a 31-page study open on the kitchen table. I've read it twice already, and I'm grinning like an idiot. This is the kind of research that points the same way as what I've believed since I started the shop: that light matters for how we feel, and that living this far north, with the dark months ahead and most of our days spent indoors, it's worth thinking about the light we're missing. I sell these things because I believe in them, which is exactly why I'll tell you below where this study runs out.

Why thyroid research is personal for me

My mum had a tumour on her thyroid, and she's lived with thyroid problems for as long as I can remember. So when I started reading about red light and the thyroid, I did what any son with a shop full of devices would do. I told her about it. Probably too enthusiastically (I'm a former personal trainer, enthusiasm is the only setting I've got). She now uses red light every other day, with the mega torch from the shop, and it's become part of her routine.

So you can imagine how it felt to open a brand new study from researchers in Kosovo and University College London and see mainstream science pointing the same way as the advice I'd given her. Hello Mum, yes, I'm writing about you.

I want to be careful, though. Her situation isn't the exact one this research looked at, and her bloods are hers and her doctor's business, not something I'll wave around on the internet. I'll come back to that. First I want to show you what the researchers actually did, because the details are where the good stuff is.

What the 2026 study actually did

The paper came out in Antioxidants on 1 September 2026. It's led by Venera Berisha-Muharremi, an endocrinologist in Prishtina, working with colleagues including Reem Hanna at University College London. You can read the full paper here: the study on PubMed Central.

They recruited 50 women aged 20 to 50, all with Hashimoto's thyroiditis, the autoimmune condition where your immune system attacks your thyroid. The detail I love is who they chose. These women were "euthyroid", which means their thyroid hormone levels were still inside the normal range, and none of them had started treatment. In other words, exactly the people who get told they're fine. That isn't a dig at doctors. Medicine is built to act once the numbers drift out of range, and that makes sense. It just leaves a gap for anyone sitting in the middle, with antibodies up, hormones in range and feeling rubbish.

Half the women chose thyroid-directed light. The other half chose selenium, plus vitamin D if their levels were low (vitamin D being the modern, less revolting cousin of the spoonful of tran many of us grew up with in Norway). The light group had an 820nm near-infrared (nær-infrarød) laser held against the skin over each side of the thyroid, eight spots in total, 20 seconds each. That's under three minutes a session, twice a week, for three weeks. Six sessions, then nothing more. Everyone had bloods and a thyroid ultrasound before treatment, straight after the three weeks, and again three months later.

The researchers call this photobiomodulation (fotobiomodulasjon). I'll keep saying red light therapy (rødlysterapi), because that's what most of us call it, even though a laser at 820nm sits just beyond what your eye sees as red.

What changed in the red light group

A 2026 study published in Antioxidants found that glutathione, its main measure, rose from a median of 204 to 255 in the light group straight after treatment (the paper reports it in mg/L), and was still 246 three months later. In the supplement group it went the other way, from 230 to 211 and then 210. By the three-month check, every woman in the light group had glutathione inside the reference range, up from just over half (52%) at the start.

The thyroid antibodies are where I sat up in my chair. Anti-TPO, one of the two main Hashimoto's markers, fell from a median of 443 to 105 right after treatment, then to 83 three months on. Anti-Tg, the other one, went from 173 to 68 to 40. In the supplement group neither moved in a statistically meaningful way. The thyroid itself got smaller too, from an average of 15.9 mL to 12.1 mL by three months, while the supplement group stayed at about 15.4 mL. The authors think that likely reflects less inflammation and swelling rather than anything more dramatic, though they're upfront that they don't know yet.

Then there's the finding that made me put my tea down. None of the women in the light group needed to start levothyroxine, the standard thyroid hormone medication, during the study. In the supplement group, 24% started it by the end of treatment, and some needed a higher dose by the three-month check. Nobody in either group reported any side effects.

Small study, yes. Promising, also yes.

Why glutathione matters for your thyroid

Glutathione is the part I find most interesting, so let me stay with it for a minute.

Start with how you feel. When your cells are coping, you wake up with something in the tank and the afternoon doesn't fall off a cliff. When they aren't coping, everything costs a bit more than it should and nobody can tell you why. Ask yourself now: which of those two is closer to your Tuesday?

Underneath that sits oxidative stress. Making thyroid hormone is a messy chemical job that literally uses hydrogen peroxide as an ingredient, so your thyroid already works in a rough neighbourhood. Add an immune system that's attacking it and the mess multiplies. Glutathione is the antioxidant your own cells make to mop it up, and the paper describes a vicious circle where inflammation and oxidative stress feed each other.

Red light is thought to work by being absorbed by an enzyme in your mitochondria called cytochrome c oxidase, the last step in your cells' energy chain. The idea is that it helps the enzyme work better and, along the way, switches on your cells' own antioxidant defences rather than just mopping up after the fact. That's the biology Michael Hamblin has spent years mapping, and the authors lean on it throughout. Selenium and vitamin D feed the antioxidant system from the supply side, while light is proposed to switch on the machinery from the inside. Which matters more for you, nobody knows yet, and this study measured glutathione, not the mechanism itself.

It isn't just one study

One study never settles anything, and I'd be wary of anyone who says otherwise. What encourages me is that this one lands on top of a pile of earlier work leaning the same way. Most of it calls the treatment low-level laser therapy, which is the same family of light.

The best known is the Brazilian work led by Danilo Höfling at the University of São Paulo. In a randomised, placebo-controlled trial of 43 people with Hashimoto's-related hypothyroidism, ten sessions of 830nm laser over the thyroid were followed by nine months of monitoring. The laser group later needed a much lower levothyroxine dose than the placebo group, around 39 micrograms a day compared with 107, and had lower TPO antibodies too. You can read the full paper here: Höfling 2013 on PubMed. One important detail: in that trial levothyroxine was withdrawn and restarted under medical supervision with regular bloods. That's the trial design, not something to try at your kitchen table. The same trial's ultrasound follow-up found healthier blood flow inside the gland in the laser group, which you can see here.

Six years later the same group went back to check safety. Nodules turned up at a similar rate in the laser and placebo groups, nothing was malignant, and the laser group still needed a lower levothyroxine dose (roughly 95 versus 142 micrograms a day). The antibody differences had faded, and the authors say the effects look temporary, so repeat sessions would probably be needed. Here's the long-term follow-up.

A sham-controlled trial in Free Radical Research in 2024 gave laser or sham to people with Hashimoto's who were already on levothyroxine. Glutathione and quality of life improved more in the active group, and you can find it here. A study of 350 people with Hashimoto's found a bigger rise in T3 and a bigger drop in TPO antibodies when light was added to supplements than with supplements alone (Ercetin 2020). And the Kosovo team has run a six-month trial in 74 women (here) and a 12-month trial in 98 women (here), where adding light to supplements improved thyroid markers and brought thyroid volume down.

The honest bit: what this study can't tell us

I said I'd get here. I'm excited about this paper, not blind to it.

Nobody was assigned to a group at random. The women picked their treatment, which can quietly stack the deck, because people who choose a laser may differ from people who choose a capsule. Participants and the treating doctor knew who was getting what, though the lab staff didn't. It's 50 women at one clinic, and the follow-up stops at three months. The light group also started with higher anti-TPO numbers (not statistically different, but higher), so part of the fall could be regression to the mean, where very high readings drift down on their own. The authors say all of this themselves. They also note their selenium dose, 100 micrograms, was lower than some earlier studies used, so I wouldn't read this as light beating selenium. If you take selenium and vitamin D already, I'm not telling you to stop. This isn't me saying your supplements are pointless, and for most people in Norway I still think they come first (I explained why in Hashimoto's in Norway: why so many women are told they're fine).

Two more things matter if you're thinking about trying this. In the light group TSH drifted down and free T3 and free T4 went up, but free T4 climbed above the reference range in 40% of the women by three months, up from 4%. The authors call the overall picture favourable, yet a hormone number heading above range is exactly why anything aimed at your thyroid belongs alongside proper blood tests and a doctor who knows you. And the light group's glutathione dipped a little between the end of treatment and the three-month check. That fits with Höfling's finding that effects fade, and it's the main reason I'd never call this a one-and-done job.

Then there's the device question. The laser in the study was a 200mW clinical unit, applied by a doctor in contact with the skin at eight marked spots. That isn't the same as any home device, including mine. I test every device with a spectrometer before I stock it, and I've sent things back when the readings didn't match the claims, so I can tell you what my torch actually delivers. 810nm and 820nm are close neighbours, which is why I think this research deserves attention, but dose and delivery are different. Almost nobody selling red light devices in Norway talks about the biphasic dose response, where too much light can cancel the benefit rather than add to it, and I think that's a problem. It matters more at the thyroid than almost anywhere, because that gland responds to tiny shifts. Short and consistent beats long and heroic.

Back to Mum. People with thyroid cancer, nodules needing treatment or previous thyroid surgery were excluded from this study, which is another reason I'd never hold up one trial as a promise for someone else. If you have a history like hers, the first conversation is with your own doctor, not with me or any blog. What I can say is that reading this paper made me feel better about passing the idea on.

Where this leaves you

Here's where I've landed, and you're welcome to land somewhere different.

If you suspect Hashimoto's, or you've been told you're fine and you know you aren't, the first move isn't a light at all. It's asking for the full picture: free T3, free T4 and both thyroid antibodies, TPOAb and TgAb. If you want the older research in more detail, my earlier post red light therapy and your thyroid: the research goes through the Höfling trials.

If you and your doctor are happy for you to try light alongside your care, keep it modest. A small device aimed at the front of the neck is a very different thing from a big panel at a distance, which is why I'd point you to the portable devices collection first. The 810nm mega torch is the one my mum uses, and the red light panels suit the rest of your body better. Short sessions, consistent, bloods rechecked on whatever schedule your doctor sets.

And if you're staring at your own numbers and wondering whether any of this applies to you, message me. I'm not a doctor and I won't pretend to be one, but reading papers like this for people is what I'm here for.

Disclaimer: This post is for educational purposes only and does not constitute medical advice. Thyroid conditions, including Hashimoto's thyroiditis and thyroid tumours, require diagnosis and ongoing management by a qualified healthcare professional. Never stop, start or adjust thyroid medication without medical supervision. Speak with your doctor before using red light therapy near your thyroid.

Frequently Asked Questions

Can red light therapy help with Hashimoto's thyroiditis?

Early research suggests it might. A 2026 study of 50 women with early Hashimoto's found that those who received thyroid-directed red and near-infrared light had lower thyroid antibodies, a smaller thyroid and higher glutathione than a comparison group taking selenium and vitamin D. Earlier randomised trials from Brazil also found lower levothyroxine requirements after laser treatment over the thyroid. The studies are small and mostly used clinical lasers rather than home devices, so it should be discussed with your doctor and used alongside your treatment, not instead of it.

Does red light therapy increase glutathione?

In the 2026 Antioxidants study, serum glutathione rose from a median of 204 to 255 straight after six sessions of thyroid-directed near-infrared light and was still 246 three months later. A sham-controlled trial published in 2024 in Free Radical Research also found bigger glutathione improvements in the active laser group than in the sham group. Researchers think light may switch on the body's own antioxidant defences through the mitochondria rather than acting as an antioxidant itself. It is still early evidence, and most of it comes from people with Hashimoto's rather than the general population.

Can I use a red light torch on my thyroid at home?

The studies used clinical lasers applied by trained doctors, so a home device is not an exact match. If you have a thyroid condition, speak to your doctor first, especially if you have had a thyroid tumour, nodules or thyroid surgery, as those people were excluded from the 2026 study. If you and your doctor are comfortable with it, the sensible approach is short, consistent sessions with the front of the neck exposed rather than long ones. Too much light can reduce the benefit, and the thyroid responds to small changes, so blood tests matter more than how you feel. You can message me and I will talk through the research with you, but I am not a doctor.

Can red light therapy replace levothyroxine?

No. In the studies covered here, levothyroxine decisions were made by doctors using blood tests, and the trials where doses changed did so under medical supervision. Red light therapy is being studied as something that might sit alongside standard care, not replace it. Never stop, reduce or change thyroid medication without talking to your doctor first.

Hva viste den nye studien om rødlysterapi og skjoldbruskkjertelen?

En studie fra 2026 i tidsskriftet Antioxidants fulgte 50 kvinner med tidlig Hashimotos sykdom. Kvinnene som fikk nær-infrarødt lys mot skjoldbruskkjertelen hadde lavere antistoffer, mindre skjoldbruskkjertelvolum og høyere nivåer av glutation tre måneder senere, sammenlignet med en gruppe som tok selen og vitamin D. Ingen i lysgruppen trengte å starte med levotyroksin i løpet av studien. Studien var liten og deltakerne valgte selv behandling, så resultatene er lovende, men ikke et bevis. Snakk alltid med legen din før du endrer noe som har med skjoldbruskkjertelen eller medisinene dine å gjøre.

References

Berisha-Muharremi V, Tahirbegolli B, Humolli A, Hanna R. Comparative effects of photobiomodulation therapy versus conventional antioxidant supplementation on serum glutathione levels in euthyroid chronic autoimmune thyroiditis: a prospective open-label interventional clinical trial. Antioxidants. 2026;15(9):1105. https://pmc.ncbi.nlm.nih.gov/articles/PMC13603426/

Höfling DB, Chavantes MC, Juliano AG, et al. Low-level laser in the treatment of patients with hypothyroidism induced by chronic autoimmune thyroiditis: a randomized, placebo-controlled clinical trial. Lasers in Medical Science. 2013;28(3):743-753. https://pubmed.ncbi.nlm.nih.gov/22718472/

Höfling DB, Chavantes MC, Juliano AG, et al. Assessment of the effects of low-level laser therapy on the thyroid vascularization of patients with autoimmune hypothyroidism by color Doppler ultrasound. ISRN Endocrinology. 2012. https://pubmed.ncbi.nlm.nih.gov/23316383/

Höfling DB, Chavantes MC, Buchpiguel CA, et al. Safety and efficacy of low-level laser therapy in autoimmune thyroiditis: long-term follow-up study. International Journal of Endocrinology. 2018. https://pubmed.ncbi.nlm.nih.gov/30532779/

Tunç S, Altuntaş ŞL, Atmaca M, et al. The effect of low-level laser therapy on the oxidative stress level and quality of life in patients with Hashimoto's thyroiditis. Free Radical Research. 2024;58(4):249-260. https://doi.org/10.1080/10715762.2024.2339892

Ercetin C, Sahbaz NA, Acar S, Tutal F, Erbil Y. Impact of photobiomodulation on T3/T4 ratio and quality of life in Hashimoto thyroiditis. Photobiomodulation, Photomedicine, and Laser Surgery. 2020;38(7):409-412. https://pubmed.ncbi.nlm.nih.gov/32186976/

Berisha-Muharremi V, Tahirbegolli B, Phypers R, Hanna R. Efficacy of combined photobiomodulation therapy with supplements versus supplements alone in restoring thyroid gland homeostasis in Hashimoto thyroiditis: a clinical feasibility parallel trial with 6-months follow-up. Journal of Personalized Medicine. 2023;13(8):1274. https://pmc.ncbi.nlm.nih.gov/articles/PMC10455109/

Berisha-Muharremi V, Tahirbegolli B, Phypers R, Hanna R. Evaluation of thyroid volume normalisation in female patients with Hashimoto thyroiditis: a 12-month comparative study of combined supplements and photobiomodulation versus supplementation alone. Biomedicines. 2025;13(7):1555. https://pmc.ncbi.nlm.nih.gov/articles/PMC12292235/

About the author: Dominic Lamb has run LightTherapy.no from Drammen, Norway since 2018, Norway's oldest independent red light therapy store. He's a former personal trainer who tests every device he sells with a spectrometer, and he writes these posts because he started with sore joints and flat Northern European winters of his own. You can read more about him and the store here.