A claim circulating on social media and in tabloids warns that creatine – the world’s most popular sports supplement – can trigger deep vein thrombosis (DVT), dangerous blood clots that form in the legs and can travel to the lungs. The claims describe the risk of DVT as a rare and serious complication of creatine supplementation, with a video on Facebook describing how there are scientific journals reporting on otherwise physically active people developing DVT as a complication of creatine consumption. A related post goes further, pointing to a specific case: a physically active man in his 20s who presented with a three-day history of cramping and swelling in his calf.
The timing matters, because creatine has become one of the most talked-about supplements online, with estimates placing the global market at $1.37 billion in 2025, with projections reaching $8.68 billion by 2033 on the back of fitness influencers and a fast-growing following among women and older adults. With so many more people now being interested in the benefits of creatine supplementation, a claim that it could trigger dangerous clots is exactly the kind of worry worth checking carefully.
When we researched the claim, we found that the scientific journal it referred to was very likely a case report published in the medical journal Cureus in December 2025, titled “Creatine Use and Thromboembolism Risk in Athletes” and authored by clinicians at the Shrewsbury and Telford Hospital NHS Trust in the UK. The report describes a physically active man in his 20s who developed a calf DVT, and its authors propose that creatine may raise thrombotic risk through dehydration and hemoconcentration, a condition where the number of red blood cells increase due to there being less plasma in blood vessels.
Neither the video nor the post names the report, but the patient they describe matches the Cureus case almost exactly – a physically active man in his 20s presenting with a three-day history of cramping and swelling in his calf – which is why we are confident it is the source they are drawing on. The journal authors stop short of claiming proof, framing the case instead as a reason to re-evaluate creatine’s vascular safety profile and calling for larger studies.
The study was then picked up by medical trade outlets. Medical Dialogues, for instance, reported that the case highlighted a possible link between creatine supplementation and venous thromboembolism (VTE) in young athletes, and from there the framing spread online into a simpler, more alarming claim: that creatine causes clots.
When we researched the claim, we came across a rebuttal issued by the Scientific Advisory Board of Creatine for Health. According to their article, the patient in the Cureus report had two of the most well-established triggers for venous clots sitting in plain sight – a recent four-hour flight, which means prolonged immobility, and a current smoking habit. Later testing revealed a third: he carried Factor V Leiden, a genetic mutation that is itself a textbook risk factor for thrombosis. Tellingly, the Cureus report itself acknowledges the flight but waves it away, arguing that this factor alone is unlikely to fully account for the event – a judgement the rebuttal characterises as an oversight of key clinical data, given how potent the combined risks were.
Then there is the nature of the evidence. The case report describes a single patient and a single sequence of events. By design it cannot establish that one thing caused another; at most it can float a hypothesis for others to test – which the Cureus authors themselves implicitly concede, calling for larger prospective studies and randomized trials to better define the relationship between creatine and thromboembolism. The report also omitted the basics needed to assess any supplement link at all: the dose taken, how long he had been using it, his hydration status, and whatever else he was consuming alongside it.
So what does the larger body of evidence show? The most comprehensive safety analysis to date, published in 2025, pooled side-effect data from 685 human clinical trials covering 12,839 people taking creatine against 13,452 on placebo. It found the proportion of studies reporting side effects was effectively identical between the two groups – 13.7 per cent for creatine versus 13.2 per cent for placebo – with no rise in markers of kidney or other organ damage. The same study searched a database of 28.4 million global adverse-event reports and found mentions of creatine vanishingly rare, at well under a thousandth of a per cent.
On clots specifically, a 2024 scoping review that combed the literature for any link between creatine and deep vein thrombosis found only a handful of isolated case reports and concluded that they reaffirmed the supplement’s overall safety while flagging hydration as the sensible precaution. In short, decades of randomised trials and large cohort studies have not linked creatine to thrombosis; what exists are scattered anecdotes, not a pattern.
We rate the claim that creatine causes blood clots as false. It rests on a single case report whose own details point to smoking, immobility, and a genetic predisposition as the likely culprits, and it runs against the weight of decades of higher-quality research.
Creatine monohydrate remains one of the most heavily studied supplements in existence, with an exceptional safety record for healthy adults at recommended doses of three to five grams a day. Anyone with an existing clotting disorder, kidney disease, or other medical condition should of course check with a doctor before starting any supplement – but that is ordinary caution, not evidence that creatine causes clots.
