Creatine and Hashimoto's: Why This Cheap, Everyday Supplement Could Help More Than You Think

Creatine is a natural substance your body makes itself, using three everyday building blocks it gets from protein in your diet (arginine, glycine, and methionine). You also get creatine directly from food, mainly animal muscle from red meat and fish. But you don't have to eat meat in order to make creatine. You can get those amino acids from all foods including plants.

Think of creatine as a little rechargeable battery pack for your cells. Your body's cells run on a form of energy that gets used up very quickly and needs constant "topping up." Creatine's job is to sit inside your cells, ready to hand over a quick burst of energy the moment it's needed, in your muscles when you move, and in your brain when you think.

Most of your body's creatine (around 95%) is stored in your muscles, with the rest in your brain, heart, liver and kidneys. So while it's best known as a "muscle" supplement, its job is really about energy - everywhere in the body that needs it.

An underactive thyroid slows down how efficiently your body's cells produce and use energy. That's a big part of why fatigue, brain fog, and slow muscle recovery are such classic Hashimoto's symptoms, your cells simply aren't topping up their energy stores as well as they should.

Creatine helps support exactly this process. It won't fix your thyroid, and it isn't a replacement for proper thyroid treatment, but by helping your cells keep their energy supply topped up, it may genuinely ease some of the day-to-day symptoms that come with living with an underactive thyroid.

Fatigue and low energy Because creatine helps your cells regenerate their energy supply, many people notice they feel less drained and heavy-legged once they're taking it consistently. This has been studied directly in other fatigue-related conditions, with encouraging results, and the underlying mechanism (supporting cellular energy) is directly relevant to hypothyroid fatigue too.

Brain fog and memory A small but growing number of good-quality studies have looked at creatine and brain function, including in women going through perimenopause and menopause. One 2025 trial found that just eight weeks of daily creatine improved women's reaction times and brain energy levels compared to a placebo. A review pulling together 16 separate studies found creatine improved memory, with more modest effects on focus and mental speed. It doesn't work identically for everyone — some people respond more than others — but for a symptom as frustrating as brain fog, it's a promising, low-risk option worth trying.

Muscle strength and muscle loss This is where creatine has by far the strongest evidence with decades of solid research. An underactive thyroid makes it easier to lose muscle and harder to build it back. Creatine, especially combined with some form of strength or resistance exercise, is one of the best-studied ways to protect and rebuild lean muscle. In some studies, effectively reversing several years' worth of muscle loss.

Mood and low mood Because your brain also relies on the same energy system, researchers have tested creatine alongside antidepressant treatment. In one study of women with depression, adding creatine to their usual antidepressant led to noticeably better improvement than the antidepressant alone — with a difference showing up within just two weeks. This doesn't mean creatine is a treatment for depression on its own, but it's a meaningful, women-specific finding for a group who experience low mood and anxiety more than average.

Perimenopause symptoms Several of the newest and most exciting studies have focused specifically on women going through perimenopause and menopause. A life stage that very often overlaps with a Hashimoto's diagnosis or flare-up. These studies have found creatine can ease mood swings, support memory and mental sharpness, and help preserve muscle and strength as hormones shift. As oestrogen falls, your body's own creatine production and usage change too, which may be part of why supplementing becomes particularly helpful during this transition.

Bone strength As oestrogen declines around menopause, bone health becomes a real concern for many women. Early research suggests that creatine, particularly alongside strength training, may help support the structural strength of bone, on top of its established role in protecting the muscle strength and balance that help prevent falls.

Blood sugar regulation This benefit is less well known, but the evidence is solid. In a trial involving people with type 2 diabetes, adding creatine to an exercise programme led to a meaningfully better improvement in blood sugar control than exercise alone. Because blood sugar imbalances are common alongside Hashimoto's, this is a genuinely useful, if under-discussed, benefit.

Inflammation and immune balance Early laboratory research suggests creatine may help calm certain inflammatory pathways in the body and support healthier immune cell function, which is interesting for anyone managing an autoimmune condition like Hashimoto's. However, this research is still at an early, mostly laboratory-based stage. There isn't yet a human study testing creatine's direct effect on Hashimoto's antibodies or thyroid inflammation specifically. I'd describe this as a promising area to watch, not a proven benefit, which is still exciting.

Look back over that list — fatigue, brain fog, muscle loss, low mood, perimenopausal symptoms, bone health, blood sugar swings, and possibly even inflammation. This isn't a random collection of unrelated benefits. Every single one of them is something women with Hashimoto's are more likely to experience, often several at once, and often for years.

That's really the heart of why creatine deserves more attention in this community. It's not a miracle cure, and it's absolutely not a substitute for proper thyroid treatment. But it's one of the very few supplements where the same underlying mechanism — helping your cells manage and use energy better — genuinely touches almost every major symptom area that Hashimoto's affects. Most supplements target one thing. Creatine's reach across energy, muscle, mood, brain function, bone and blood sugar is unusually broad, and it happens to overlap almost perfectly with the Hashimoto's symptom picture.

On top of that, it's one of the most thoroughly tested supplements that exists. It's been studied in well over 600 clinical trials involving more than 26,000 people, some followed for over a decade, and it has consistently shown a strong safety record. No meaningful differences in side effects compared to a placebo, including for kidney, liver and heart health in people with no pre-existing conditions. It's also inexpensive — often just a few pounds a month — with no need for fancy formulations or proprietary blends.

Put simply: it's cheap, it's safe for the vast majority of women, and its benefits map almost exactly onto the symptoms Hashimoto's causes. This is pretty rare to find in one supplement alone.

Choose creatine monohydrate. This is the plain, original form of creatine, and it has by far the most research behind it. Newer, pricier versions (like creatine HCl or "buffered" creatine) are marketed as being better absorbed, but there's no good evidence they actually work better than monohydrate.

Look for third-party testing, or a Creapure-certified product. This means the product has been independently checked for purity. Creapure is a well-known, trusted German-made form of creatine monohydrate.

Keep it simple. You don't need flavourings, stimulants, or a long ingredients list. A plain powder is fine, and usually the cheapest option too.

Where to buy in the UK. I recommend The Natural Dispensary. You can use my code SABR10 at checkout for 10% off your creatine (and any other supplements you're picking up).

Here's the direct link - you'll need to create an account first:

https://naturaldispensary.co.uk/high-flyer-creatine-monohydrate-powder-300g

A simple daily dose of 3–5g is what's used in almost all of the studies above, including the ones specifically in women. This is the dose I'd suggest for most people.

You can start straight away at this dose — there's no need for a "loading phase" of higher doses. It just takes a few weeks longer (around 3–4 weeks) to reach its full effect in your body, compared to about a week if you use a short loading phase of around 20g a day.

I'm going to start offering Q&A workshops for simple questions like these, where you can get professional support for the price of a coffee, instead of relying on Google rabbit holes and potential unqualified online advice.

Take it regularly. The exact timing doesn't matter much.

There's no need to take breaks or "cycle off" it. The research includes people taking it continuously for years without any issue. It is one of the safest and most studied supplements out there.

There's no set "course" of creatine. It's designed to be taken long-term, a bit like how you might think about a good quality vitamin D or omega-3 supplement. I'd suggest treating it as an ongoing daily habit, and reviewing it periodically alongside your thyroid blood tests and how you're feeling overall, rather than stopping after a set number of weeks.

Creatine is safe for most women, but it's not right for everyone. Please avoid it, or only use it with your doctor's guidance, if you:

Have bipolar disorder. There's good evidence creatine can trigger manic or hypomanic episodes in people with bipolar I or II, even if your mood is currently stable and you're on medication. This is the clearest reason to avoid it.

Are pregnant or breastfeeding. We simply don't have enough safety research in humans during pregnancy and breastfeeding yet, so the sensible choice is to avoid it unless a specialist specifically advises otherwise.

Have diagnosed kidney disease. The excellent safety data above applies to people with healthy kidneys. If you have kidney disease, this is a conversation for your kidney specialist or GP, not something to decide on your own.

Have significant liver problems. Your liver is involved in processing creatine, so if you have a liver condition, check with your doctor first.

Take certain medications, such as some anti-inflammatory painkillers, water tablets (diuretics), or lithium. These can affect your kidneys or fluid balance, so it's worth checking with whoever prescribes them before adding creatine.

Creatine is safe for most women, but it's not right for everyone. Please avoid it, or only use it with your doctor's guidance, if you:

Have bipolar disorder. There's good evidence creatine can trigger manic or hypomanic episodes in people with bipolar I or II, even if your mood is currently stable and you're on medication. This is the clearest reason to avoid it.

Are pregnant or breastfeeding. We simply don't have enough safety research in humans during pregnancy and breastfeeding yet, so the sensible choice is to avoid it unless a specialist specifically advises otherwise.

Have diagnosed kidney disease. The excellent safety data above applies to people with healthy kidneys. If you have kidney disease, this is a conversation for your kidney specialist or GP, not something to decide on your own.

Have significant liver problems. Your liver is involved in processing creatine, so if you have a liver condition, check with your doctor first.

Take certain medications, such as some anti-inflammatory painkillers, water tablets (diuretics), or lithium. These can affect your kidneys or fluid balance, so it's worth checking with whoever prescribes them before adding creatine.

Creatine is one of the safest, most thoroughly researched supplements available, and its benefits on energy, muscle, mood, brain function, bone strength, blood sugar, and possibly inflammation, line up remarkably closely with what so many women with Hashimoto's struggle with. It won't treat your thyroid condition, and the inflammation research in particular is still early days. But as a genuinely low-cost, low-risk addition alongside good thyroid care, it's one of the most useful, under-used supplements I know of for this community.

As always, do check with your GP or specialist before starting anything new, especially if you have a mood disorder, kidney or liver condition, or are pregnant or breastfeeding.