Short answer: Gelatin and hydrolyzed collagen (collagen peptides) both come from collagen. In one small head-to-head study in 10 men, 15 g of either, with vitamin C, raised blood amino acids similarly, and a collagen-building marker tended to rise about 20% with both, though not significantly.1 Each has only a few human trials, mostly small.
| Collagen peptides (hydrolyzed collagen) | Gelatin | |
|---|---|---|
| Head-to-head result | Same rise in blood amino acids as gelatin; collagen marker up about 20%, not significant1 | Same as collagen peptides in that study1 |
| Other trials | 53 older men with sarcopenia, 15 g a day with 12 weeks of strength training: more fat-free mass and strength than placebo2 | 8 men, 15 g with vitamin C before rope-skipping: collagen-building marker doubled3 |
| Study sizes | 53 people in the largest trial cited2 | 8 and 10 people31 |
| Taken with | Strength training in the sarcopenia trial2 | Vitamin C, 1 hour before short exercise3 |
Ten active men took placebo, 15 g of vitamin C-enriched gelatin, 15 g of hydrolyzed collagen, or a gummy with both, 1 hour before 6 minutes of jump rope, in random order. All three raised blood amino acids similarly. A marker of new collagen tended to rise about 20% with gelatin and hydrolyzed collagen but not with placebo or the gummy. Results varied a lot between people, and no difference was statistically significant.1
Gelatin. In 8 healthy men, 15 g of vitamin C-enriched gelatin 1 hour before rope-skipping doubled a blood marker of collagen building, compared with placebo.3
Collagen peptides. In 53 men aged about 72 with sarcopenia doing 12 weeks of strength training, 15 g a day of collagen peptides gave more fat-free mass (4.2 vs 2.9 kg), more leg strength and more fat loss than placebo.2
The one direct comparison found no clear difference, and every study here is small. These trials measured blood markers or muscle with training, not injury rates. This is general information, not personal advice. More detail: the Collagen Peptides and Gelatin guides.