About Gelatin
Gelatin is partially hydrolyzed collagen — larger, mostly intact protein fragments (~50–100 kDa) versus the 2–5 kDa peptides used in skin and joint RCTs. That size difference matters: hydrolyzed collagen peptides have multiple RCTs across skin elasticity, joint pain, and bone density (Verisol, Fortigel, Peptan); gelatin has essentially none of those endpoints studied. The single most-cited gelatin trial — Shaw 2017 (PMID 27852613, Am J Clin Nutr) — enrolled 8 healthy males, used 15 g gelatin + 50 mg vitamin C one hour before rope-skipping, and measured a doubling of the blood collagen-synthesis marker PINP. That is a surrogate biomarker in a tiny acute crossover, not a clinical outcome. There are no RCTs showing gelatin improves skin appearance, joint pain, tendon healing, or any other endpoint a consumer would care about. Treat gelatin as a low-bioavailability, evidence-light collagen substitute — products dosing it at 5–10 g/day should not score equivalent to a clinically dosed hydrolyzed collagen peptide product (see `collagen` entry). Pre-workout protocols using gelatin + vitamin C for tendon support have weak mechanistic backing only.
What Gelatin supports
- Supplies collagen-precursor amino acids (glycine, proline, hydroxyproline)
- One acute trial suggests pre-exercise gelatin + vit C raises collagen-synthesis markers
- Lower bioavailability than hydrolyzed collagen peptides
How much Gelatin to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
5–15
g
Only one small acute-mechanism RCT (Shaw 2017 PMID 27852613, n=8 healthy males) used 5 g vs 15 g + vit C pre-exercise and reported doubled PINP (collagen-synthesis biomarker) at 15 g only. No skin or joint clinical-endpoint RCTs exist for gelatin specifically. Range mirrors the trial dose ceiling, not validated efficacy.
Clinical evidence
Limited clinical evidence. Strongest evidence: Shaw 2017 (PMID 27852613) — n=8 healthy males, 15 g pre-exercise raised blood PINP (collagen-synthesis biomarker). No clinical-endpoint RCTs for skin or joint outcomes
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