Creatine monohydrate is the most studied supplement in sports nutrition history, with over 500 peer-reviewed papers and a safety record spanning three decades. The International Society of Sports Nutrition's 2017 position stand, authored by Dr. Richard Kreider (Texas A&M), called it "the most effective ergogenic nutritional supplement currently available." The emerging evidence for cognitive benefits and neuroprotection has expanded interest well beyond the gym.
Cognitive enhancement under stress is the most intriguing application. A 2018 Experimental Gerontology meta-analysis (k=6, n=281, led by Dr. Konstantinos Avgerinos at the University of Thessaly) found creatine improved short-term memory and reasoning under conditions of sleep deprivation, mental fatigue, and acute stress. Effect sizes were notably more pronounced in vegetarians and vegans, who typically have 20-30% lower baseline brain creatine stores (measured via MR spectroscopy by Dr. Caroline Rae, University of Sydney, 2003, n=45).
Neuroprotection evidence is emerging across multiple conditions. Dr. M. Flint Beal (Weill Cornell Medicine) has proposed creatine as a neuroprotective agent in Parkinson disease and ALS based on bioenergetic deficits in these conditions. Phase II trials have shown promise, though Phase III results have been mixed — the 2015 NINDS NET-PD trial (n=1,741) found no benefit for early Parkinson disease at 10 g/day.
Depression is a surprising but studied application. A 2023 Journal of Affective Disorders meta-analysis (k=5, n=232, led by Dr. Brent Kious at the University of Utah) found creatine as an adjunct to SSRIs produced a moderate improvement in depression scores (SMD=-0.52) in treatment-resistant patients. The proposed mechanism involves restoring phosphocreatine reserves in frontal brain regions, where PET imaging shows hypometabolism in major depression.
Dosing: 3-5 grams of creatine monohydrate daily, according to the ISSN position stand. Loading phases (20 g/day for 5-7 days) saturate stores faster but are not necessary for long-term use. Creatine monohydrate remains the recommended form; alternatives (creatine HCl, buffered creatine, creatine ethyl ester) have not demonstrated superior bioavailability or efficacy in head-to-head trials.
Safety: excellent long-term profile across studies lasting up to five years. Dr. Jose Antonio (Nova Southeastern University) has documented in multiple trials that the weight gain (1-2 kg) is intracellular water retention in muscle, not fat. Creatine does not cause kidney damage in healthy kidneys — the persistent myth originates from misinterpretation of creatinine levels, which rise naturally as muscle creatine stores increase. The ISSN explicitly states: "there is no scientific evidence that creatine supplementation causes kidney dysfunction."