Mixed
Prolonged supplementation with 15g/day of collagen peptides, when combined with resistance exercise training, significantly increases fat-free mass (FFM) in recreationally active men compared to placebo, likely through enhanced passive connective tissue adaptations rather than increased contractile muscle fiber hypertrophy.
If you are lifting weights regularly, adding 15 grams of collagen peptides daily (specifically after your workout) can help you gain more lean mass than training alone. This gain appears to come from stronger connective tissues rather than bigger muscle fibers, which may help you lift heavier or recover faster. It is not a replacement for high-quality protein but a useful addition.
COL showed a significant increase in fat-free mass (FFM) compared with the placebo group (p < 0.05)... As the observed increase in FFM was not reflected in differences in fCSA hypertrophy between groups, we assume enhanced passive connective tissue adaptations in COL due to CP intake.
Why this rating
Randomized, double-blind, placebo-controlled trial with a reasonable sample size (n=57) and clear statistical significance for the primary outcome.
Source
Prolonged Collagen Peptide Supplementation and Resistance Exercise Training Affects Body Composition in Recreationally Active Men
Marius Kirmse et al. · Nutrients · 2019
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