Oral Fish Collagen Peptides Protect Skin From UV Aging Through Absorbed Dipeptides Gly-Pro and Pro-Hyp

Oral fish scale collagen peptides protected mice from UVB-induced wrinkles and skin damage over 12 weeks, with the active dipeptides Gly-Pro and Pro-Hyp confirmed in blood plasma after ingestion.

Lee, Hyun-Jun et al.·Bioscience·2019·
RPEP-043112019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Not classified
Evidence
Not graded
Sample
Not reported

What This Study Found

Fish scale collagen peptide NS (CPNS) was characterized with Gly-Pro identified as a representative bioactive dipeptide. Key findings:

- In cell culture: CPNS reduced MMP-1 (collagen-degrading enzyme) production and increased type 1 procollagen synthesis in human dermal fibroblasts

- In rats: Oral CPNS dramatically increased plasma concentrations of Gly-Pro and Pro-Hyp, confirming bioavailability

- In 12-week hairless mouse study: Oral CPNS significantly attenuated UVB-induced wrinkle formation, reduced transepidermal water loss, decreased epidermis thickening, and increased skin hydration compared to UV-exposed controls

Key Numbers

How They Did This

CPNS from fish scale was characterized by prep-HPLC and LC-MS/MS. In vitro effects were tested on human dermal fibroblasts. Oral bioavailability was confirmed by measuring plasma dipeptide levels in rats after CPNS ingestion. In vivo photoprotection was assessed in hairless mice exposed to UVB for 12 weeks while receiving oral CPNS supplementation.

Why This Research Matters

Collagen supplements are a multibillion-dollar industry, but the mechanism of oral collagen benefits has been debated. This study provides concrete evidence that specific dipeptides from collagen actually reach the bloodstream and that oral supplementation protects against UV-induced skin aging in a controlled animal model.

The Bigger Picture

The collagen peptide supplement market has long been criticized for lacking mechanistic evidence. This study addresses that gap by identifying the specific bioactive peptides that survive digestion and reach the bloodstream, and demonstrating their functional effects on UV-damaged skin. This type of mechanistic validation is needed to move collagen supplements from consumer marketing claims to evidence-based recommendations.

What This Study Doesn't Tell Us

Animal study in hairless mice — UV response and skin structure differ from human skin. The UV exposure protocol was artificial and may not perfectly model real-world sun damage. Only fish scale collagen was tested; results may differ for bovine or marine collagen from other sources. No human clinical trial data was presented. Specific dosing information relative to typical human supplement doses wasn't detailed.

Questions This Raises

  • ?Do the blood levels of Gly-Pro and Pro-Hyp achieved in rats translate to similar levels in humans taking standard collagen supplement doses?
  • ?Would these collagen dipeptides show the same photoprotective effects in human skin aging studies?
  • ?How do the bioactive peptide profiles differ between fish, bovine, and marine collagen supplements?

Trust & Context

Key Stat:
12 weeks protection Oral fish collagen peptides significantly reduced UVB-induced wrinkles, water loss, and skin thickening in hairless mice
Evidence Grade:
This is a preclinical study combining in vitro, pharmacokinetic, and in vivo experiments. While comprehensive for an animal study, the evidence is not directly applicable to human supplement recommendations without clinical trial confirmation.
Study Age:
Published in 2019 in Bioscience, Biotechnology, and Biochemistry. The findings contributed to the growing scientific basis for collagen supplementation that has continued to develop since.
Original Title:
Orally administered collagen peptide protects against UVB-induced skin aging through the absorption of dipeptide forms, Gly-Pro and Pro-Hyp.
Published In:
Bioscience, biotechnology, and biochemistry, 83(6), 1146-1156 (2019)
Database ID:
RPEP-04311

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Do collagen supplements actually get absorbed into the body?

Yes — this study confirmed that specific dipeptides (Gly-Pro and Pro-Hyp) from fish collagen appeared in blood plasma after oral consumption. These small peptides survive digestion and are absorbed into the bloodstream, where they can exert biological effects on skin cells.

Can collagen pills protect against sun damage?

In this mouse study, oral collagen peptides significantly reduced UV-induced wrinkles and skin damage over 12 weeks. However, collagen supplements should complement — not replace — sunscreen and other UV protection measures. Human clinical trials are needed to confirm these benefits in people.

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Cite This Study

RPEP-04311·https://rethinkpeptides.com/research/RPEP-04311

APA

Lee, Hyun-Jun; Jang, Hye-Lim; Ahn, Dong-Kyu; Kim, Hun-Jung; Jeon, Hee Young; Seo, Dae Bang; Lee, Ji-Hae; Choi, Jin Kyu; Kang, Seok-Seong. (2019). Orally administered collagen peptide protects against UVB-induced skin aging through the absorption of dipeptide forms, Gly-Pro and Pro-Hyp.. Bioscience, biotechnology, and biochemistry, 83(6), 1146-1156. https://doi.org/10.1080/09168451.2019.1580559

MLA

Lee, Hyun-Jun, et al. "Orally administered collagen peptide protects against UVB-induced skin aging through the absorption of dipeptide forms, Gly-Pro and Pro-Hyp.." Bioscience, 2019. https://doi.org/10.1080/09168451.2019.1580559

RethinkPeptides

RethinkPeptides Research Database. "Orally administered collagen peptide protects against UVB-in..." RPEP-04311. Retrieved from https://rethinkpeptides.com/research/lee-2019-orally-administered-collagen-peptide

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.