Collagen supplements (marine, bovine, etc.): beauty and health promises, what does science really say? Are they safe?

Collagen based complements do they really fulfill their promises?

Firmer skin, fewer wrinkles, stronger nails, thicker hair, "comfortable" joints... Collagen supplements—especially marine collagen—are a hit. But does the solid clinical evidence match the marketing hype? And on the safety front, can they be consumed without risk? Here's a clear, sourced, and accessible point.

Collagen: What Human Studies (Really) Show

“Skin” results: modest and heterogeneous effects

Several meta-analyses of randomized trials report statistically significant improvements in hydration, elasticity, and sometimes wrinkles… but with modest effect sizes , short studies, and often industry-funded (potential bias). For example:

• Meta-analysis 2023 (26 RCTs, n=1,721): improvement in hydration and elasticity vs placebo.

• Meta-analysis 2025 (23 RCTs): overall benefits, but disappear when only studies not funded by industry are considered. In other words: the effect is not found in independent trials.

• Remember : there are positive signals, especially among older people, but it is difficult to assert a net “visible” impact for everyone .

  
  

Joints (osteoarthritis)

Some reviews suggest modest pain reduction and functional improvement with collagen derivatives (hydrolyzate or UC-II). Effects vary depending on the formula, dose, and duration.

“Global” health (hair/nails/gut/bones)

Evidence is more limited and heterogeneous ; there is a lack of independent, long-term trials with robust clinical endpoints.

Marine collagen: a special case… especially marketing

“Marine” is presented as better absorbed and “cleaner” . In reality, absorption depends mainly on the hydrolyzed form (peptides) and the dose, not only on the origin. Direct comparisons “marine vs bovine/porcine” remain poorly documented . Furthermore, on the European regulatory side, “more elastic skin / fewer wrinkles” claims were not authorized (e.g. VeriSol®P dossier not validated by EFSA).

Safety: Is collagen safe to consume?

Overall, yes to the recommended doses — with nuances

Collagen supplements (including marine collagen ) are generally well tolerated at usual doses (1–10 g/day). Recent work on marine products has assessed the presence of heavy metals (arsenic, lead, mercury): the levels measured remained below regulatory limits and the risk was deemed negligible at the recommended dosages (beware, however, of variations between brands ).

Points of vigilance

• Allergies : marine collagen is not recommended if you are allergic to fish/shellfish .

• Quality & Traceability : Choose controlled brands (contaminant analyses, declared origin, certificates). Metal levels may vary depending on the species and fishing area.

• Pregnancy/breastfeeding, pathologies : limited data → seek medical advice , especially in cases of liver/kidney disease or long-term treatment. The health authorities (ANSES) generally remind us that supplements are not harmless ; they can cause adverse effects and interact with medications. See the ANSES recommendations

  
  

Why so many strong allegations?

The beauty industry and consumer expectations are enormous. The motivation is to stay young, but naturally, without medical or surgical intervention. People are looking for the miracle food or dietary supplement to limit the appearance of wrinkles. This offers manufacturers an opportunity to sell a relatively harmless product (but above all, it is poorly controlled because it belongs to the class of dietary supplements, which are not regulated like medications) and to make profits on products that are inexpensive to manufacture but sell for a high price per gram.

Frequently Asked Questions

• Does marine collagen “firm” the skin? Small to moderate effects on hydration/elasticity are observed, but their clinical significance (“visible” result) remains uncertain, especially outside of funded studies.

• Does it really help joints? Modest improvements in pain and function are reported in some meta-analyses, depending on the form (hydrolysate, UC-II), dose , and duration .

• Is it safe? Generally yes at the recommended doses, but caution should be exercised in case of fish (marine) allergy, medical conditions, or pregnancy/breastfeeding; product quality is essential.

• Are there any official “more elastic skin” claims authorized in Europe? No : some “skin/elasticity/wrinkle” health claims have been rejected (e.g. EFSA/VeriSol®P). EFSA Journal+1

Conclusion

Collagen supplements (including marine collagen ) may offer modest benefits for the skin and, in some cases, joints . However, the true extent and sustainability of these benefits remain uncertain , especially outside of sponsored trials . In terms of safety, they are generally well tolerated at recommended doses, with some cautionary points (fish allergies, quality/contaminants, special situations).

What is my opinion on collagen supplements?

I discovered these supplements during a facial treatment. The practitioner recommended using collagen to help my skin produce it, since we produce less and less as we age (hence the appearance of wrinkles...).

I found the idea interesting, but I wondered how consuming fish scraps—bones, skin, and scales—could possibly help my skin produce collagen?

I have to admit that I haven't found any scientific evidence that consuming this "collagen" actually increases collagen production. Instead, I've found marketing claims devoid of any basis or valid proof of effectiveness. I even think that, not really knowing what we're consuming, it could even have negative effects on our health. Indeed, apart from these supplements, we do not even eat this type of waste, we remove it from the fish before consuming them, don't we?

What about your experience with collagen supplements?

• I have never tried such supplements
• I have tried and I find it efficient on my skin
• I have tried and I haven't seen any improvement