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Randomized trial · measured the question itself

A 16-week collagen trial in 87 women: better wrinkles and density, elasticity unchanged

Žmitek and colleagues · Nutrients · 2024

Original title: The Effects of Dietary Supplementation with Collagen and Vitamin C and Their Combination with Hyaluronic Acid on Skin Density, Texture and Other Parameters: A Randomised, Double-Blind, Placebo-Controlled Trial.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Mixed

Both products improved skin density, texture and wrinkle severity compared with placebo. Neither changed skin elasticity or hydration. Adding hyaluronic acid gave no extra benefit.

The study at a glance

Type of study
Randomized trial
Who or what was studied
87 people · 87 women aged 40 to 65
What was tested
5 g hydrolysed collagen with 80 mg vitamin C, with or without 30 mg hyaluronic acid, for 16 weeks, vs placebo
What it measured
The question itself: skin wrinkles, elasticity and hydration
Daily amount
5 g a day
How long
16 weeks
Who has a stake
Company stake
Funded in part by Tosla d.o.o., which made the study products.
Journal
Nutrients, 2024
Source
PubMed record 38931263. This page is based on the abstract only.

How much this study counts

  • ✓Randomized: people were put into groups by chance, so the groups start out alike.
  • ✓Compared with a placebo, a dummy treatment.
  • •Medium size: 87 people.
  • •Lasted 16 weeks.
  • ✓Measured the question itself: skin wrinkles, elasticity and hydration.
  • –Company stake: Funded in part by Tosla d.o.o., which made the study products.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

Each dot is one on-topic paper on this question. Steps near the top answer the question more directly.

↑ Stronger evidence

  1. Trials in people: wrinkles, skin elasticity and moisture

    15

    13 benefit, 2 mixed

    ↑ This study is the ringed dot

  2. Trials in people: other measures

    1

    1 benefit

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does collagen reduce skin aging?”

Unclear; higher-quality trials found no effect.

Confidence: low. Based on 22 on-topic papers.

Read the full answer

Of the other 14 papers on the same step: 13 benefit, 1 mixed. This one found mixed. It differs from most of them.

  • Quoted in “What we found”: Not every trial agreed. In 99 women, collagen raised skin water content but not elasticity. A trial lasting 16 weeks saw no change in elasticity or hydration.
  • Quoted in “What we found”: Several tested drinks mixed collagen with vitamin C, zinc, biotin or joint compounds, so the effect of collagen alone cannot be separated.
  • Part of the finding “Some trials found no change in key measures”.
  • Part of the finding “Many products were blends or company-linked”.

Other papers on the same step

See all 22 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads differed. The reviewer checked the abstract and kept the first read. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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