Mixed
A nutritional supplement is considered ergogenic only if peer-reviewed human studies demonstrate it significantly enhances exercise performance or muscle hypertrophy with long-term ingestion, not just acute effects or preclinical data.
Do not be misled by supplements that claim to work instantly or are only supported by animal studies. Look for products that have been tested in humans over weeks or months of training. The most reliable supplements are those with long-term efficacy data showing they help you build muscle or perform better consistently over time.
a consensus exists to suggest that a nutritional supplement is ergogenic if peer-reviewed studies demonstrate the supplement significantly enhances exercise performance following weeks to months of ingestion... our view is that such evidence does not warrant 'Excellent Evidence to Support Efficacy' if there is a lack of long-term efficacy data.
Why this rating
This is a position statement/consensus definition by the ISSN, not an empirical finding itself.
Source
ISSN exercise & sports nutrition review update: research & recommendations
Chad M. Kerksick et al. · Journal of the International Society of Sports Nutrition · 2018
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →