Creatine Facts and Myths: Should You Be Concerned When Training with Endometriosis?
If you read our previous article about creatine and endometriosis research, you may now have more questions than before. Understandably. When scientific research suggests that a substance may promote disease progression, the natural reaction is concern, especially if that substance is a popular pre-workout supplement.
This article attempts to provide a reliable answer to a question that's been asked more and more frequently: whether a woman with endometriosis who trains and is considering creatine supplementation should be concerned. The answer isn't simple, and it wouldn't be fair to pretend otherwise, but there are a few things worth knowing before making a decision.
Where does creatine in endometriosis lesions come from?
Let's start with what the 2024 study by Chen and colleagues actually showed, because that's important for understanding the whole discussion.
Scientists observed elevated creatine concentrations in ectopic cells and in the peritoneal fluid of women with endometriosis. They then demonstrated that this creatine is primarily derived from endogenous synthesis, meaning that the disease cells themselves produce more of it because they have higher activity of the GATM enzyme. Simply put, endometriosis lesions produce creatine themselves, using it to protect themselves from the mechanism that should eliminate them.
This finding applies to creatine produced internally by diseased cells and does not directly apply to creatine taken externally, either through diet or supplementation.
But here comes a complication that cannot be ignored.
Where does legitimate concern begin?
In the same study, an experiment was conducted on a mouse model of endometriosis. The rodents were administered creatine directly into the peritoneal cavity, i.e., externally rather than endogenously. The results showed that mice receiving creatine had more endometriosis lesions, larger in weight and volume, than mice in the control group.
This is an observation that cannot be downplayed or dismissed as "just mice." Experimental administration of external creatine in an animal model promoted disease progression, and the authors themselves discuss creatine's potential as a biomarker and therapeutic target.
At the same time, it's important to understand the limitations of this experiment. Creatine was administered directly into the peritoneal cavity, a completely different route than oral supplementation. The concentrations used in the experiments were high, and the mouse model does not fully replicate human physiology. No one has yet investigated whether, and to what extent, oral creatine supplementation affects its concentration in the peritoneal fluid of women with endometriosis.
Therefore, we do not have an answer to the question of whether creatine from the supplement reaches the endometriosis foci in concentrations that could be of clinical significance, but we also do not have studies that would rule out such an effect.
What do we know about creatine in women?
Creatine is one of the most studied dietary supplements in the history of sports science. Its safety and effectiveness in terms of physical performance, strength, and muscle mass are well documented in the general population. A 2016 review by Ellery and colleagues indicates that women may derive specific benefits from creatine supplementation, including mental health, cognitive function, and energy management during various stages of reproductive life.
However, none of these studies were conducted in women with endometriosis. There are no clinical data on the safety or effects of creatine supplementation specifically for this condition, and this knowledge gap is important in itself.
Physical activity and endometriosis: this is certain
Regardless of the question about creatine, one thing is well-documented: regular physical activity, including strength training, has a beneficial effect on women with endometriosis. Exercise reduces chronic inflammation, improves insulin sensitivity, lowers cortisol levels, and promotes the production of endorphins, which alleviate pain perception. Skeletal muscle is the largest consumer of glucose in the body, and its efficient function supports overall metabolic and hormonal balance.
The desire to exercise with endometriosis is something that should be supported and nurtured, not limited by fear. The question of creatine supplementation is a separate issue and should not influence decisions about physical activity itself.
Strength training, yoga, Pilates, swimming, and Nordic walking don't require creatine to be beneficial. Many women with endometriosis train effectively and derive real health benefits without any supplementation.
How do you think about this decision today?
If you are an active woman with endometriosis and are considering creatine supplementation, the situation is as follows.
On the side of caution, there are laboratory studies and a mouse experiment suggesting that creatine may promote endometriotic cell survival and disease progression in an animal model. There are also no clinical studies confirming the safety of supplementation in this group.
The lack of clear contraindications is due to the fact that the results refer to experimental models, and the path from laboratory observations to clinical recommendations is long and ambiguous. There are no human studies indicating the harmful effects of oral creatine supplementation in endometriosis.
In situations like these, when knowledge is incomplete and questions arise about supplements and chronic illness, the most prudent step is to speak with your doctor. A gynecologist or endometriosis specialist can assess your individual case, the stage of the disease, and your current treatment plan in light of this decision. This isn't a question that science has answered for you, but it's also not a question you have to face alone.
What do we need to know more?
To answer the question about creatine and endometriosis with complete certainty, science needs clinical trials involving women with endometriosis who take oral creatine, measure creatine levels in their peritoneal fluid, and track disease activity. Such studies currently do not exist.
This is an honest answer to the state of knowledge in 2026. We don't know enough to say you can safely supplement, and we don't know enough to say you should absolutely avoid it. However, we do know that the question is valid and worth asking a specialist who knows your situation.
Train, listen to your body and ask your doctor
Endometriosis shouldn't prevent you from being active and taking care of your body's strength. Physical activity is one of the tools that truly works in the context of this disease, and it's worth building it in a way that's tailored to your current abilities.
The question of creatine is important and deserves to be taken seriously, not reassuringly stated, which is ahead of the scientific evidence. If you train, are considering supplementation, and have endometriosis, this topic is worth discussing with your doctor, who will help you assess it in the context of your clinical situation.
Sources
Chen S, Liu X, Zhang Y. Creatine promotes endometriosis by inducing ferroptosis resistance via suppression of PrP. Advanced Science, Volume 11, Number 4, Pages 2304112, December 2024.
Ellery SJ, Walker DW, Dickinson H. Creatine for women, a review of the relationship between creatine and the reproductive cycle and female specific benefits of creatine therapy. Amino Acids, volume 48, number 8, pages 1807, August 2016.
Machado M. Reassessing the proposed creatine PrP axis in endometriosis, methodological and mechanistic considerations. Advanced Science, Volume 13, Number 2, Pages 2501042, February 2026.
Vercellini P, Vignali M, Somigliana E. Endometriosis, pathogenesis and treatment. Nature Reviews Endocrinology, volume 10, number 5, pages 261, May 2014.
ESHRE Endometriosis Guideline Development Group. Endometriosis, guideline of the European Society of Human Reproduction and Embryology. ESHRE Guidelines Office, Central Building, Grimbergen, January 2022.
