Safety and Efficacy of Commercially Available Pre-Workout Supplements

Abstract

Objectives: The purpose of this review was to determine the safety of various pre-workout supplements that utilize proprietary blends in comparison with some of the most common individual ingredients; caffeine, creatine, and B-alanine. We hypothesized that there will be a greater number of adverse events reported for proprietary products than for the individual active ingredients. Additionally, we also wanted to look at the efficacy of the same aforementioned products. We hypothesized that there would be no statistically significant differences in performance between the two arms. Methods: Four databases were searched for subjects that were 18-35 years of age that were already physically active. The number of participants included in each trial ranged from 6 to 98. Results: Caffeine was the only individual compound that affected health markers, increasing mean arterial pressure (MAP) (P<0.05), and HR in 2 of the 3 studies (P<0.05) significantly. Both caffeine and creatine showed a benefit in maximal exertion, but only caffeine improved endurance at doses of 3mg/kg (P<0.05). Proprietary blends did not show a benefit, but serious adverse events such as liver failure were reported. Conclusions: Individually caffeine, creatine, and B-alanine all look to be safe at the recommended doses in healthy and active individuals, with caffeine and creatine benefitting performance. Pre-workout blends should be safe in theory, but due to the unregulated nature of the supplement industry there are a number of serious adverse events that occur. Untested amphetamine-like compounds seem to be the most common addition, with contamination of other ingredients such as anti-depressants occurring as well.