Clinical studies on collagen
Does collagen really work — or is it just marketing? We lay out what clinical studies on hydrolysed collagen peptides show, where the evidence is strong and where it reaches its limits. Honestly framed, with the actives in our own formula: FORTIGEL® and Peptan®.
Key facts at a glance
The evidence on collagen is nuanced: best documented is the effect of hydrolysed collagen peptides — short-chain, bioactive peptides that the body absorbs efficiently. Three things are decisive: the right peptide form, an adequate daily dose and consistent intake over several weeks. Under these conditions, clinical studies show measurable effects on skin, nails and joints.
- —Best documented: hydrolysed collagen peptides — not gelatine or pure collagen.
- —Randomised studies on collagen peptides showed significantly better skin elasticity after 4 weeks (Proksch et al., 2014).
- —Effect needs dose (10'000 mg) and consistency — usually 8 to 12 weeks.
- —Collagen is not a medicine: individual results vary.
What studies show after 4, 8 and 12 weeks
Collagen does not work overnight, but over weeks. This progression sums up what clinical studies on bioactive collagen peptides have observed over time — qualitatively, without glossed-over numbers.
First visible results
In a randomised, placebo-controlled study on collagen peptides, skin elasticity improved significantly versus placebo after 4 weeks (Proksch et al., 2014).
The effects become clearer
In a second placebo-controlled study, eye wrinkle volume was significantly reduced after 8 weeks (Proksch et al., 2014).
Longer courses
Studies on joint discomfort and connective tissue run for 12 weeks and longer (Clark et al., 2008; König et al., 2018). Collagen is not a medicine — results are individual.
The basis is published clinical research on hydrolysed collagen peptides (incl. Proksch et al., 2014; Clark et al., 2008; König et al., 2018). We do not run studies of our own. The progression is shown qualitatively — specific values depend on the study, the dose and the individual.
What stands behind each active
Not all collagen is the same. These four actives form the backbone of our formula — and all four have been examined in scientific studies.
FORTIGEL® — bovine collagen (Gelita®)
10'000 mg · Type I & IIIBioactive collagen peptides obtained by enzymatic hydrolysis from bovine gelatine. 10'000 mg per daily dose — the declared amount in our formula. Hydrolysed collagen peptides of this kind have been examined in published clinical studies on skin and joints (incl. Proksch et al., 2014; Clark et al., 2008).
Peptan® — marine collagen
Type I · wild-caught (MSC)Hydrolysed type I collagen peptides from MSC-certified fishing — an alternative to bovine collagen for anyone avoiding beef.
Vitamin C
Cofactor of collagen synthesisVitamin C is indispensable for the body's own collagen synthesis: it acts as a cofactor of the enzymes that stabilise collagen. Without enough vitamin C the body cannot form stable collagen — this link is considered established and is EFSA-recognised.
Hyaluronic acid
20 mg · moisture20 mg of hyaluronic acid per daily dose — the declared amount in our formula. Hyaluronic acid occurs naturally in skin and synovial fluid, where it binds water.
Why the form decides the effect
A study is only as meaningful as the active it examines. The decisive factor with collagen is bioavailability — how much actually reaches the bloodstream and the connective tissue. Hydrolysed peptides already exist in short chains of two to three amino acids and are absorbed through the gut in that form.
Pure collagen or gelatine, by contrast, are too large-molecular to work in that form — a key reason why blanket criticism of “collagen” does not do justice to the nuanced body of evidence. We quote no absorption percentage: we have no robust independent source for one for liquid collagen.
What does Stiftung Warentest say?
Stiftung Warentest is sceptical of collagen supplements. The core of the criticism: some of the studies are manufacturer-funded, the effects vary from person to person, and a balanced diet already provides the building blocks the body needs to form its own collagen. These points are valid — and we take them seriously.
We do not contradict in blanket terms; we differentiate. Collagen is not a miracle cure, and anyone who promises that loses credibility. But “doesn't work” is just as imprecise as “always works”.
The evidence is strongest for hydrolysed peptides
Blanket criticism often targets gelatine or pure collagen. For hydrolysed, bioactive peptides such as FORTIGEL® and Peptan® the evidence is considerably more robust — and those are exactly what we use.
Dose and consistency decide
Many disappointing self-tests fail because of too low a dose or too short a course. Our formula delivers 10'000 mg per day — the order of magnitude shown to work in studies.
Individual results vary
Age, diet, skin type and lifestyle influence the result. We do not promise a guaranteed effect — and we quote no figure we cannot back with a published study.
Honesty over hype
We quote no invented percentages and no before-and-after miracles. We show the evidence as it is — with its strengths and its limits.
Our standard: honest rather than loud. If collagen isn't right for you, we'll say so — even if that means we don't sell a product.
Clinical studies on collagen — your questions
Is the effect of collagen scientifically proven?
For hydrolysed, bioactive collagen peptides there are several clinical studies showing measurable effects on skin, nails and joints. The framing matters: best documented are peptides (not gelatine or pure collagen), in an adequate dose and taken over several weeks. Under these conditions the evidence is solid, though not comparable to a medicine.
How quickly do studies show an effect?
In a randomised, placebo-controlled study skin elasticity was significantly better than placebo after 4 weeks, and eye wrinkle volume was significantly reduced after 8 weeks (Proksch et al., 2014). Studies on joints and connective tissue run for 12 weeks and longer (Clark et al., 2008; König et al., 2018). Results are individual.
Why is Stiftung Warentest sceptical?
Stiftung Warentest criticises, among other things, that some of the studies are manufacturer-funded and that the effects vary individually. That is a valid point and we do not dispute it. The evidence is strongest for hydrolysed peptides in an effective dose — but whether and how strongly collagen works for you is individual. That is why we promise no guaranteed effect.
What is the difference between FORTIGEL® and Peptan®?
FORTIGEL® (Gelita®) are hydrolysed bovine collagen peptides types I and III. Peptan® is hydrolysed marine type I collagen from MSC-certified wild catch — the alternative for anyone avoiding beef. Both are hydrolysed; we have no head-to-head comparison of the two raw materials.
How high should the daily dose be?
Clinical studies mostly work with several grams of collagen peptides per day. Our formula delivers 10'000 mg per daily dose — the order of magnitude at which studies show an effect. Under-dosed products, such as single capsules with 500 mg, do not reach this amount.
Does collagen replace a healthy diet?
No. A balanced diet with enough protein and vitamin C is the basis of the body's own collagen formation. A collagen drink is a targeted supplement — not a replacement. That is exactly why we combine the peptides with vitamin C, the cofactor of collagen synthesis.
Evidence, not promises.
The strongest evidence lies in hydrolysed peptides at an effective dose. That is precisely what Collagen Pro-Active Advanced delivers: 10'000 mg of FORTIGEL® per daily dose (25 ml).
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