Tier 2 — strong

24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain

Kristine L. Clark, Wayne Sebastianelli, Klaus R. Flechsenhar, Douglas F. Aukermann, Felix Meza, Roberta L. Millard, John R. Deitch, Paul S. Sherbondy, Ann Albert

Current Medical Research and Opinion 2008 24(5):1485–1496

Bibliography

DOI: 10.1185/030079908X291967
PubMed: PMID 18416885
Funding: Declaration of interest (verbatim): "This research was sponsored by GELITA Health GmbH, Eberbach, Germany. […] The nutritional supplement collagen hydrolysate used for this research project was provided by GELITA Health GmbH, Eberbach, Germany."
Competing interests: No explicit competing interests statement beyond funding disclosure. GELITA Health GmbH — a commercial collagen hydrolysate manufacturer — both sponsored the research and supplied the test product. Co-author Klaus R. Flechsenhar has industry-adjacent affiliation. Statistical analysis was performed by Dr. Imma U. Fischer at the Institute for Biostatistics, Tübingen, Germany. Editorial assistance was provided by ACCESS Medical Group, Chicago, IL, USA. Substantial commercial conflict of interest.

Study snapshot

Design	Multi-centre, prospective, randomised, double-blind, placebo-controlled trial
Model	Varsity/club-level Penn State University athletes with activity-related joint pain but no diagnosed osteoarthritis or degenerative joint disease
Sample	147 randomised (72 M, 75 F); 97 completed evaluable analysis (48 treatment, 49 placebo); mean age ~20 years
Intervention	10 g/day collagen hydrolysate (GELITA FORTIGEL, liquid formulation) or 25 mL matched-taste maltodextrin/xanthan gum liquid placebo, once daily, for 24 weeks
Duration	24 weeks (5 study visits at baseline, 6, 12, 18, and 24 weeks)
Endpoints	Joint pain at rest — VAS, physician-assessed; Joint pain at rest — VAS; participant-assessed; Joint pain when walking, standing, carrying, lifting, running straight, changing direction (VAS); Frequency of alternative therapy use

What the study showed, in plain terms

Athletes commonly develop joint pain during training and competition — not from arthritis or injury, but from ordinary wear-and-tear on cartilage. Because collagen is the main protein in cartilage, researchers hypothesised that swallowing collagen daily might help slow that wear or reduce the pain associated with it. This 2008 trial was the first large, well-designed test of that idea in a young, healthy athletic population.

Kristine Clark and colleagues at Penn State University enrolled 147 college athletes over a period of nine months. Each athlete was randomly assigned to take either 10 grams of a specific collagen hydrolysate product or a placebo drink every day for 24 weeks. Neither the athletes nor the physicians measuring their joint pain knew who was getting what. Over the course of six months, pain was recorded at rest and during activities like walking, standing, carrying objects, lifting, and changing direction — all rated on a 10-point scale.

By the end of the six months, athletes taking collagen reported significantly less joint pain in almost every measured category than those taking placebo. They also used other pain remedies (such as anti-inflammatory drugs or heat packs) less often — 12 times over the trial compared to 39 times in the placebo group. Interestingly, the differences did not become clear until after roughly three months of daily supplementation, suggesting that collagen takes time to produce its effect. The trial established collagen hydrolysate as a defensible option for reducing exercise-related joint discomfort in athletes without diagnosed joint disease, and it remains the most-cited joint trial in the field.

Key findings

Joint pain at rest (physician-assessed) improved significantly with collagen vs. placebo: −1.37 ± 1.78 vs. −0.90 ± 1.74 points, p = 0.025.
Joint pain when walking (participant-assessed) reduced −1.11 ± 1.98 vs. −0.46 ± 1.63 (p = 0.007).
Joint pain when standing: −0.97 ± 1.92 vs. −0.43 ± 1.74 (p = 0.011).
Joint pain when carrying objects: −1.45 ± 2.11 vs. −0.83 ± 1.71 (p = 0.014).
Joint pain when lifting: −1.79 ± 2.11 vs. −1.26 ± 2.09 (p = 0.018).
Alternative therapy use dropped in collagen group: 12 vs. 39 instances (p < 0.001) at final visit.
In the pre-specified knee-arthralgia subgroup (n = 63), six of nine pain parameters reached statistical significance, with knee pain when walking improving 156% more in the collagen group (p = 0.003).
Effect size for joint pain when walking was 0.36 for the whole cohort, 0.45 for the knee subgroup — small-to-moderate by convention, but meaningful in a young otherwise-healthy population.
Effect became apparent only after ~3 months — consistent with slow cartilage remodelling timelines rather than acute analgesic effect.

What this study can and cannot tell us

High attrition: only 97 of 147 randomised subjects were included in the analysis population, driven in part by exclusion of ineligible retrospectively-identified participants and by athletes who missed follow-up visits.
Wide range of sport disciplines was allowed, not standardised — an athlete's joint load in basketball differs substantially from swimming, and the trial did not stratify or randomise by sport.
Only oral 10 g/day dose tested; no dose-response established in this trial.
Young athletic cohort (mean age ~20 years) — findings do not extrapolate to older adults, non-athletes, or people with diagnosed osteoarthritis.
Substantial commercial conflict of interest — study sponsored by GELITA Health GmbH (manufacturer), and the FORTIGEL product tested is a GELITA proprietary formulation.
Multiple hypothesis testing was addressed via Bonferroni-Holm adjustment, but with 15 tested endpoints the ceiling for detecting real effects is lower than a single-primary-endpoint trial would show.
Effect sizes are small to moderate. The trial demonstrates statistical significance but the clinical magnitude of joint pain reduction is modest.
Placebo (maltodextrin/xanthan gum liquid) does not control for amino acid load of a protein supplement.

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