Creatine has become one of the most talked-about supplements for women. Once associated mainly with gym-goers and athletes, it is now widely recommended for muscle strength, bone health, brain function and support through the menopause, and there is good research behind many of those uses.
So when headlines started suggesting that creatine might encourage endometriosis, it understandably caused concern among the one in ten women living with the condition, and among the practitioners supporting them. In this article I'll explain what the research actually found, why it needs to be interpreted carefully, and what I think is a sensible approach for now.
If you'd like to understand endometriosis more broadly, including why it's now seen as a whole-body inflammatory condition and how nutrition and lifestyle can help, you may like to read my article Endometriosis: why it's a whole-body condition, and where nutrition fits.
What the research found
The concern comes from two studies published in 2024 and 2025 by the same research group in China [1, 2].
The first study found higher levels of creatine in the pelvic fluid and in endometriosis lesion cells of women with endometriosis than in women without the condition. In laboratory experiments, creatine appeared to help lesion cells resist ferroptosis, a form of iron-dependent cell death that would normally help clear them. In mice, those given creatine developed more, and larger, lesions [1, 2].
The second study focused on macrophages, immune cells that play a central role in endometriosis by helping lesions establish a blood supply and grow. Analysing cells from women with endometriosis, the researchers found that macrophages in the pelvis were enriched with creatine and were producing more of it. When they exposed macrophages to creatine in the laboratory and in a mouse model, the cells shifted into a "repair" mode that encouraged blood vessel growth, scar tissue formation and the spread of endometriosis-like cells [2].
Taken together, the researchers proposed that creatine may help endometriosis lesions survive and grow.
Why we need to be careful about these findings
This is genuinely interesting science, and it adds to our understanding of how the immune system and metabolism shape endometriosis. But it is a long way from telling us whether taking creatine supplements affects endometriosis in women.
The key experiments were in mice and cells. Findings in animal models often don't translate directly to people, and no study has yet looked at women with endometriosis who take creatine.
The work hasn't been independently replicated. Both studies come from the same research group, and science is far more reliable once other teams reproduce the results.
The creatine found in women was the body's own. The body makes creatine every day. Higher levels in pelvic immune cells may be a consequence of the disease process rather than a cause, and no study has tested whether creatine taken by mouth changes levels in the pelvis. Most supplemental creatine is taken up by muscle.
The human samples were small. A published critique of the research pointed out that factors such as diet, supplement use, kidney function and the stage of the menstrual cycle weren't controlled for, and that the creatine levels used in the laboratory may not reflect what happens in the body [3].
It is also worth saying that creatine is naturally present in meat and fish. Nothing in this research suggests changing a normal, balanced diet.
What this means for you
There is no evidence that creatine supplements harm women with endometriosis. But there isn't yet evidence that they are safe for this specific group either, and the early findings are enough to warrant some caution. My current approach is a measured one:
If you have endometriosis and are thinking about starting creatine, I'd discuss it with your doctor or nutritional therapist first, rather than taking it simply because it is popular.
If your main goal is building strength or protecting muscle and bone, resistance training and eating enough protein deliver most of the benefit on their own, so you don't need creatine to make progress.
If you are already taking creatine, there is no cause for alarm. It is simply worth weighing up the benefits you're getting against the current uncertainty, ideally with a professional who knows your history.
If you don't have endometriosis, this research doesn't change the picture for you.
This is an area where I expect our understanding to develop, and I'll update this article as better evidence emerges.
The bottom line
If you take one thing away from this article, I'd like it to be this: The link between creatine and endometriosis is an interesting early signal from animal and laboratory research, not proof of harm in women. It is sensible to be cautious and to talk it through with a professional, but there is no need to panic.
Want support with endometriosis?
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References and further reading
Chen SM, et al. Creatine promotes endometriosis by inducing ferroptosis resistance via suppression of PrP. Adv Sci. 2024.
Chen SM, Liu YK, Ma XQ, Wei CY, Li MQ, Zhu XY. Creatine promotes endometriosis progression by inducing M2 polarization of peritoneal macrophages. Reproduction. 2025;169(3):e240278.
Machado M. Reassessing the proposed creatine–PrP axis in endometriosis: methodological and mechanistic considerations. Adv Sci. 2026;13(44):e21907.
