Table 1.
Studies that used collagen supplementation in the treatment of dermatological changes.
| Collagen | Design | Population (n) | Period | Dose/day | Result | Reference |
|---|---|---|---|---|---|---|
| HC derived from fish (Pangasius hypophthalmus) | T-RCT | Women 45–60 years (45) | 12 weeks | 10 g | ↓face wrinkles score; ↑ elasticity, hydration, shine, and firmness | [33] |
| HC containing dipeptides (Pro-Hyp and Hyp-Gly) | D-RCT | Chinese healthy women 37–48 years (56) | 8 weeks | 2.5 g | ↑ skin hydration; ↑ facial skin elasticity; ↓ facial skin roughness | [34] |
| HC had a low ratio of dipeptide-to-product content (L-CP) and a high ratio of dipeptide-to-product content (H-CP) | D-RCT | Chinese women 35–55 years (85) | 8 weeks | 5 g | ↑ skin moisture; ↓ wrinkles area; ↓ roughness H-CP intake additionally ↓ number of wrinkles; ↓ wrinkle depth |
[35] |
| CP with 15% tripeptide form | S-RCT | Healthy Korean women and men 30–48 years (32) | 12 weeks | 3 g | ↑ stratum corneum hydration; ↔ TEWL; ↑ skin elasticity; ↔ skin erythema and pigmentation | [36] |
| CP of fish origin (PeptanF) and porcine origin (PeptanP) | D-RCT | Adult and middle-aged Japanese women 40–59 years (33) | 8 weeks | 10 g | ↑ skin hydration | [37] |
| HC with peptides of various sizes of swine-origin of the brand VERISOL@ | D-RCT | Women 35–55 years (69) | 8 weeks | 2.5–5 g | ↔ between the two collagen dosages; ↔ skin moisture and water evaporation; ↔ smoothness of the skin; ↑skin elasticity | [38] |
| HC containing more than 15% tripeptides, including 3% of Gly-Pro-Hyp. | D-RCT | Women 40–60 years (53) | 12 weeks | 1.0 g | ↑ hydration after 6 and 8 weeks of treatment; ↓ visual wrinkle after 12 weeks; ↑ skin elasticity (general elasticity and liquid elasticity) after 12 weeks | [39] |
| CP derived from fish scales (NittaGelatin Inc., India) | D-RCT | Healthy women 40–51 years (71) | 12 weeks | 3.0 g | ↑skin moisture; ↑ elasticity (crude, liquid, and biological elasticity); ↓ roughness. | [40] |
HC: hydrolyzed collagen; CP: collagen peptide; T-RCT: randomized, triple-blind and placebo controlled clinical trial; D-RCT: randomized, double-blind and placebo controlled clinical trial; S-RCT: randomized, single-blind controlled clinical trial; ↑: increase, ↓: decrease, ↔: no difference; TEWL: transepidermal water loss.