Safety of creatine supplementation: analysis of the prevalence of reported side effects in clinical trials and adverse event reports

This is the authors' abstract. We don't add key points for this paper.

BACKGROUND: Individual studies have indicated that creatine supplementation is generally well tolerated and not associated with clinically significant side effects. Nevertheless, anecdotal reports about side effects persist primarily from popular and social media and on the Internet. METHODS: This study evaluated side effects reported from 685 human clinical trials on creatine supplementation, worldwide adverse event report (AER) databases, and performed a social media sentiment analysis. The presence of side effects (No, Yes) in studies was evaluated using chi-squared analysis. The frequency of side effects among study participants was evaluated using a multivariate analysis of variance. The percentage prevalence of side effects was small, with differences between groups generally within ± 0.5%. Analysis of 28.4 million AERs revealed that the mention of Cr was rare (0.00072%), 46.3% of CAERS had no Cr in the products listed, and 63% of AERs with Cr in the product involved the use of other types of Cr or ingestion with other supplements or drugs. The overall sentiment analysis was neutral about perceptions of Cr, although those with strong perceptions about Cr were slightly more negative. CONCLUSION: Results demonstrate that Cr supplementation does not increase the prevalence or frequency of side effects when compared to participants ingesting PLA. Therefore, claims that Cr supplementation increases the risk of side effects are unfounded.