Creatine and Clots? Case Report Raises VTE Concerns in Young Athletes
UK: A case report in Cureus has highlighted a possible link between creatine supplementation and venous thromboembolism (VTE) in young athletes, emphasizing the need for awareness of vascular risks from common fitness supplements. Authored by Osama S. Abdalla from Shrewsbury and Telford Hospital NHS Trust, UK, the report describes calf deep vein thrombosis (DVT) in a healthy man in his twenties who regularly used over-the-counter creatine.
Creatine monohydrate is widely used in sports for boosting energy stores during high-intensity activity and enhancing performance. It is also associated with increased muscle mass and potential neuroprotective and cardiovascular benefits. However, rare case reports suggest creatine may, in exceptional circumstances, contribute to thrombotic events.
The patient presented with three days of cramping, tightness, and swelling in his right calf, symptoms easing during daytime activity but worsening in the evening. He denied trauma, chest pain, shortness of breath, dizziness, fever, or palpitations. His recent history included a four-hour flight. He smoked, drank alcohol occasionally, and denied anabolic steroid or illicit drug use, while reporting regular creatine use for bodybuilding.
Examination showed swelling and tenderness in the right calf and ankle, with asymmetry compared to the left leg. Peripheral pulses were intact, and cardiovascular, respiratory, and abdominal exams were unremarkable. Laboratory tests revealed markedly elevated D-dimer levels, while inflammatory markers, full blood count, coagulation profile, and renal and liver function were normal. ECG showed a normal sinus rhythm.
Doppler ultrasound confirmed an acute thrombus in the right peroneal veins. Extended thrombophilia screening was largely normal, including protein C, protein S, antithrombin, and lupus anticoagulant. Genetic testing revealed no prothrombin mutation, but the patient was heterozygous for factor V Leiden, a known thrombosis risk factor.
The authors suggest the DVT was likely multifactorial, potentially involving creatine-related osmotic fluid shifts, effects on homocysteine metabolism, recent air travel, smoking, and underlying genetic predisposition. While causality cannot be confirmed from a single case, the report adds to growing evidence raising concerns about creatine’s vascular safety in susceptible individuals.
They advise athletes and recreational users to maintain proper hydration, follow recommended dosing, and monitor for thrombosis symptoms. Clinicians should include supplement use in routine history-taking, particularly in young patients with unexplained thrombotic events.
Given the limited and inconsistent evidence, the authors call for larger prospective studies and randomized trials to better define the relationship between creatine and thromboembolism. Until more robust data are available, individualized risk assessment and careful monitoring remain key to balancing creatine’s performance benefits with potential vascular risks.
Reference:
Abdalla O S, Mudassir H, Green H, et al. (December 14, 2025) Creatine Use and Thromboembolism Risk in Athletes: A Case Report. Cureus 17(12): e99242. doi:10.7759/cureus.99242
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