New Delhi: Creatine has long been one of the most familiar supplements in the fitness world, best known for helping gym-goers lift heavier and recover
faster. But in recent months, it has stepped well beyond bodybuilding circles, with a surge in public interest driven by studies suggesting it may also support brain health—including memory, focus, and mood.
Now, however, NHS doctors have raised fresh concerns after linking creatine use to a small number of blood clot cases in young, otherwise healthy adults. The warning comes from clinicians at Shrewsbury and Telford NHS Hospital Trust, who reported a case of deep vein thrombosis (DVT) in a man in his 20s who had been taking creatine regularly. Their findings were published in the medical journal Cureus.
As per a report, the patient arrived at the hospital complaining of swelling and pain in the calf. Later, scans found that there was a clot in a deep vein in his leg, a condition that can gradually worsen if the clot moves through the blood. Doctors say that DVT can be life-threatening if a part of the clot breaks and travels to the lungs, thereby triggering pulmonary embolism. Clots can also result in a stroke if they block blood circulation to the brain or a heart attack if blood circulation to the heart is obstructed.
The patient, described as otherwise healthy, told clinicians he had been using over-the-counter creatine supplements for “bodybuilding purposes.” He had also recently taken a four-hour flight—a factor known to slightly increase clot risk due to prolonged sitting. However, the doctors noted that a journey of that length is not typically considered long enough on its own to trigger a clot in a healthy person.
What raised greater concern, they said, is that this case is not unique. The NHS team pointed to several other published medical reports in which young men developed serious clot-related complications while taking creatine. In some cases, the reported complications included pulmonary embolism and even rare clots affecting the eye.
While the number of cases remains small and does not prove cause and effect, the doctors said the pattern raises questions about whether creatine could contribute to clot risk in certain circumstances—particularly when combined with other factors that may not be obvious.
One possible explanation, they suggested, is dehydration. Creatine is known to have an “osmotic effect,” meaning it draws water into muscle cells. In some people, this could lead to relative dehydration if fluid intake is not increased. Dehydration can thicken the blood, which in turn may raise the likelihood of clot formation, especially during intense exercise or long periods of reduced movement.
That is why sports nutrition guidance often stresses hydration during creatine use — a point the doctors emphasised in their report. They also noted that creatine may act as a trigger in people with undiagnosed clotting disorders, or in those who have additional risk factors such as immobility, long travel, or high-intensity training. The authors were not careful enough to call creatine unsafe collectively. Instead, they urged experts to be cautious of the complications involved, especially whena young and fit patient develops a clot.
