Oral collagen peptides,
does it really help with Increased nail growth and reduced cracking or chipping?
research showsThe grade is C with 46 points. This was an open single-arm study in 25 women; 24 completed. The reported 12% growth increase at 24 weeks has no corresponding absolute growth rate reported in the paper. The 12% and 42% changes were within-person, and no control permits a between-group collagen effect.
ads claimThe claims of 12% faster growth and 42% less breakage must not be presented as placebo-adjusted effects. They are within-person changes without a causal between-group estimate.
Useful facts when choosing a product
- The product was VERISOL specific bioactive collagen peptides from Gelita AG, Germany, with mean molecular weight about 2.0 kDa at 2.5 g/day.
- The paper contains no separate funding or conflict-of-interest section or information. Michael Schunck and Steffen Oesser were affiliated with the Collagen Research Institute; actual Gelita funding, employment, or consulting relationships could not be confirmed.
- Verdict 001 is B for skin hydration and elasticity, verdict 032 is C for joints and bone, and verdict 034 is C with 46 points for molecular-weight and absorption marketing. This verdict concerns different nail endpoints.
What the research actually shows
Hexsel and colleagues gave 25 healthy women with brittle nails 2.5 g/day of VERISOL for 24 weeks; 24 completed. Absolute growth was 2.65±0.42 mm/month at baseline and 2.90±0.47 at 12 weeks. The paper reports a 12% increase at 24 weeks but does not give its exact absolute mean. Monthly cracking or chipping changed from 10.5±8.4 to 6.4±4.9.
Why this is classified as C (46)
A 25-person uncontrolled before-and-after study cannot estimate a between-group effect, giving C with 46 points.
Counterpoint. A preregistered blinded placebo-controlled trial of the same product is needed.
Rejudgment record. Cross-check applied — Open 25-person single-arm before-and-after study with no comparator or between-group effect, completer emphasis, and incompletely verified product relationships
| Endpoint | P | Patient-reported treatment goal - the symptom is the goal |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | EX | The clinical size of the effect could not be judged |
The scoring table and the verdict agree (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Within-person nail growth and breakage change over 24 weeks | C | A signal was observed but it was not a between-group effect. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Open-label single-center single-arm before-and-after study | 24 | Funding and conflict information were not reported in the paper; actual Gelita funding, employment, or consulting relationships could not be confirmed | Middle-fingernail growth and self-recorded cracking or chipping frequency | Growth was 2.65±0.42 mm/month at baseline and 2.90±0.47 at 12 weeks; the absolute value corresponding to 12% at 24 weeks was not reported. Monthly breakage changed from 10.5±8.4 to 6.4±4.9. | Only direct product study |
Receipt — 1 References
All 1 cited sources were verified for existence at the original page (as of 2026-08-07).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-07 · Corrections: none
Cite this verdict
[Chamgap] Oral collagen peptides x nail growth and breakage — Evidence Grade C·46. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/oral-collagen-peptides-nail-growth-breakage/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.