Long term use of creatine has not shown any adverse side effect on humans. (bodybuildingforyou.com)
Use of creatine in the elderly and evidence for effects on cognitive function in young and old. (rawbarrel.com)
«Given all the known benefits and favorable safety profile of creatine supplementation reported in the scientific and medical literature, it is the view of ISSN that government legislatures and sport organizations who restrict and / or discourage use of creatine may be placing athletes at greater risk — particularly in contact sports that have risk of head trauma and / or neurological injury.» (onnit.com)