Effects of 6 weeks of high-dose creatine monohydrate supplementation with or without guanidinoacetic acid on cognitive function

Background Creatine monohydrate (CrM) supplementation has been reported to increase brain creatine content by 5–15%, provide neuroprotective effects, and enhance cognitive function. However, since creatine does not cross the blood–brain barrier readily, it is recommended that individuals consume 10 g/day to promote cognitive benefit. Guanidinoacetic acid (GAA) is the precursor to creatine. Preliminary studies indicate that GAA supplementation (e.g. 2–3 g/d for 4 weeks) can increase brain creatine content to a similar degree as loading doses of CrM. However, more research is needed to assess the efficacy of long-term higher dose CrM supplementation on cognitive function and whether GAA may provide similar or additive benefits. To determine whether CrM and/or GAA supplementation affects cognitive function.