The Study
Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review.
This study doesn't do any new experiments—it just reads other studies and talks about what people think. So it can't say for sure if BCAA supplements make you stronger or bigger, only that some people believe they might.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
People take BCAA supplements hoping to build muscle, but scientists aren't sure if they actually work for long-term strength or muscle growth.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Not specified
- 2Not specified
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
International journal of sport nutrition and exercise metabolism
Year
2021
Authors
Daniel L Plotkin, Kenneth Delcastillo, Derrick W Van Every, K. Tipton, Alan A Aragon, B. Schoenfeld
Related Content
Claims (3)
Leucine is a type of amino acid that scientists think helps your muscles start growing right after you eat it, but we’re not sure if taking extra leucine over time actually makes you stronger or bigger muscles in the real world.
People thought taking BCAA supplements would help build muscle because lab tests showed they might affect muscle proteins, but real-life, long-term studies in people haven’t consistently shown that it actually works.
People sell BCAA supplements saying they help you build muscle and get stronger, but scientists aren’t sure if they really work because some studies say yes and others say no.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.