This meta-analysis examined the effects of collagen supplementation on skin hydration, elasticity, and wrinkles. While overall results showed benefits, these did not persist in subgroup analyses limited to non–industry-funded or high-quality studies. Let’s break down what the data really show.
Overview
- What did they test? Researchers conducted a systematic review and meta-analysis of randomized controlled trials on collagen supplementation and its effects on skin hydration, elasticity, and wrinkles. Subgroup analyses examined whether results differed by factors such as pharmaceutical industry funding and study quality.
- What did they find? Of the 893 articles screened, 23 randomized controlled trials met the inclusion criteria. Overall, collagen supplementation was linked to improvements in skin hydration, elasticity, and wrinkles. However, when only high-quality studies or those without industry funding were considered, these effects were no longer seen.
- What does it mean for you? Collagen is unlikely to be a magic bullet for skin aging. While some studies report benefits, the influence of funding and study quality raises questions about how reliable these claims are. Although there is some mechanistic rationale, the effects don’t appear to hold up in independent, high-quality trials.
What’s The Problem?
Collagen is widely marketed as a supplement for improving skin, joints, and bones. This is prominently based on its amino acid profile, which is rich in the building blocks of connective tissue — unsurprising given collagen itself is the major structural protein in these tissues 1.
In last month’s edition of REPS, Cody reviewed a study comparing collagen supplementation to a matched amino acid mixture and placebo 2. That trial found no added benefit of either supplement on protein synthesis in muscle, connective tissue, or skin beyond the effects of resistance exercise alone. While the study suggested little acute impact, it left open the possibility that repeated ingestion over time might produce different results.
This month’s meta-analysis addresses that question by focusing on the effects of collagen supplementation over time, specifically on markers of skin aging, including hydration, elasticity, and wrinkles. Importantly, the authors also examined whether study quality and funding source influenced the observed outcomes.
Purpose
This study aimed to assess the effects of collagen supplementation on skin aging outcomes including hydration, elasticity, and wrinkles, and to evaluate whether results were influenced by funding source or study quality.
Hypothesis
The authors did not explicitly state a hypothesis.
