Why don't doctors always recommend creatine?

Creatine monohydrate is well supported for strength sports: the substance increases the amount of energy-rich compounds in muscles by roughly 15 to 40%, leading to demonstrably better performance during short, maximal efforts. That is the best-supported application in the scientific literature. Whether it also helps during actual competitions in field settings is considerably less clear.

The safety picture is clearer than many doctors realise. A large review of 685 clinical studies (more than 12,800 participants) showed that the rate of adverse effects in creatine groups (13.7%) was almost identical to that in placebo groups (13.2%). The difference was less than half a percentage point. The widely heard concern about kidney damage is also not supported by the available evidence.

There are, however, legitimate reasons for caution. Very little research has been done on safety in children and teenagers, which means that restraint for that age group is justified. Newer forms of creatine such as creatine ethyl ester have no evidence showing they are better or safer than plain creatine monohydrate. And creatine users also turn out to use other anabolic supplements more often, supplements whose safety is genuinely questionable.

A practical problem is that in 2000 doctors played almost no role as a source of information: only 14% of users consulted them, while the majority followed popular magazines. The knowledge gap between scientific evidence and the consulting room is therefore decades old. Added to this, several authors of influential creatine reviews have financial ties to creatine manufacturers, which can cloud the picture and calls for additional independent studies.

For cognitive effects the indications are mixed and preliminary. The largest study in this area (123 participants, 5 grams per day for six weeks) found a small, non-significant hint of improvement in working memory, but no effect on reasoning skills. Notably, the creatine group in that study reported adverse effects significantly more often than the placebo group.