The Problem with Underdosed and Short Trials
Many of the so-called independent studies in the review used collagen doses well below the clinically effective range – just 1 – 2.5 g/day instead of the ~5 g/day supported by prior research. In addition, several lasted only 8 weeks, a timeframe too short for meaningful dermal remodeling. These design limitations make it difficult for such trials to detect changes in skin structure, regardless of collagen’s potential benefits.
When tested under optimal conditions (proper dosage, sufficient duration, and rigorous methodology), collagen can yield measurable improvements. In a 16-week randomized, placebo-controlled, double-blind trial published in Nutrients (Žmitek et al., 2024), daily supplementation with 5 g of collagen and vitamin C led to significant gains in dermal density, smoother skin texture, and reduced wrinkle depth. No changes were observed in hydration or elasticity, which is consistent with collagen’s role in supporting the dermal matrix rather than altering surface moisture.
The Real Question for Collagen Research
Even in Myung & Park’s own pooled data, collagen supplementation improved wrinkles, elasticity, and hydration across all studies combined. The debate is not about whether collagen can work, but under what conditions it works best. Dose, duration, target population, and choice of measurement tools are critical variables that influence outcomes.
Labeling collagen supplements ineffective based solely on funding sources oversimplifies the science and risks discarding valuable evidence. A more constructive approach is to focus on the conditions that consistently produce benefits. As recent high-quality trials show, collagen can be an effective tool in supporting skin structure and addressing visible signs of aging when studied (and used) correctly.
Read the full review of meta-analysis: Why the Latest Meta-Analysis on Collagen Misses the Mark