What should you avoid combining with creatine?

If you take statins for your cholesterol, creatine is a combination that calls for extra caution. Statins can themselves cause muscle damage, ranging from mild muscle pain to serious breakdown of muscle tissue (rhabdomyolysis) that can affect the kidneys. Creatine supplementation raises the blood protein creatine kinase (CK), which doctors use precisely as a marker for statin-related muscle damage. Because of creatine, that value may already be elevated without any real damage being present, making side effects harder to detect. If you are taking statins and considering creatine, always discuss this with your doctor.

Alcohol use and muscle-toxic substances are another point of concern. A study of 475 rhabdomyolysis patients found that in nearly half of all cases, toxins such as alcohol and drugs were the cause, and kidney failure also occurred in nearly half of all cases. In most cases, multiple factors played a role simultaneously. If you combine creatine with regular, heavy alcohol use, you increase the risk of muscle damage.

Caffeine has long been on the list of substances that may interact poorly with creatine. A pharmacokinetic review suggested that caffeine can affect the transporter that carries creatine into muscle tissue, which could disrupt its uptake. However, this is based on limited and indirect evidence. How much of an effect this has in practice has not been well established.

The well-known claim that creatine causes hair loss through a rise in DHT (a hormone that can shrink hair follicles) is not confirmed by the most recent research. A small randomised study (38 participants, 12 weeks, 5 grams per day) found no difference in DHT levels or hair follicle health between creatine and placebo. A caveat: several authors had financial ties to creatine manufacturers, and the study was too small to rule out rare effects.