AMA #69: Scrutinizing supplements: creatine, fish oil, vitamin D, and morea framework for understanding effectiveness, quality, and individual need

Anytime you're considering taking a supplement or someone is suggesting a supplement, you should ask the following... The first question I'm asking is, are you taking this to correct a deficiency or are you trying to achieve supra-normal levels of fill-in-the-blank.

There's reasonable evidence to suggest... that creatine does help improve various parameters of muscle performance—and it's not that subtle. I mean, it's typically in the range of 5, 10, maybe even 15.

When people, like myself—and I do take creatine—it's because we believe that supra-physiologic levels are preferential. We take this primarily to improve athletic performance, potentially increasing lean mass slightly.

While we have, again, some evidence to suggest that creatine is efficacious for cognitive function, it might turn out to be the case that you need higher doses of it.