A scientific assessment and meta-analysis not too long ago printed in The American Journal of Drugs had challenged extensively held assumptions about collagen supplementation and pores and skin well being.
The paper, authored by Korean researchers Seung-Kwon Myung, MD, PhD, and Yunseo Park, analyzed a set of randomized managed trials (RCTs) and concluded there’s “at present no scientific proof to assist the usage of collagen dietary supplements to forestall or deal with pores and skin growing old.”
Examine overview
The assessment assessed 23 RCTs involving 1,474 members. Upon preliminary assessment, the researchers acknowledged that the pooled evaluation confirmed enhancements: Collagen supplementation was linked to measurable beneficial properties in hydration, elasticity and a discount in wrinkles.
Nonetheless, subgroup analyses confirmed that trials not funded by pharmaceutical or complement firms confirmed no profit, whereas these with {industry} backing reported constructive results, the researchers reported. Equally, when solely higher-quality research have been thought-about, no important affect was noticed throughout hydration, elasticity or wrinkles, they continued.
These discrepancies prompted the authors to query whether or not earlier meta-analyses had overstated collagen’s function in pores and skin well being. In distinction to these studies, they concluded that “high-quality research revealed no important impact in all classes, whereas low-quality research revealed a big enchancment in elasticity.”
Market and scientific context
The researchers famous that collagen is a structural protein that makes up “over 90% of pores and skin mass and supplies its mechanical integrity.” With growing old, synthesis declines by “1%–1.5% yearly, inflicting deeper wrinkles and facial strains.”
The decline is compounded by diminished elastin and different molecules essential to moisture retention and firmness, which is why supplementation has been promoted as a method to enhance hydration and elasticity, they defined.
Curiosity in collagen dietary supplements has grown quickly. The evaluation reported that the market “doubled in 4 years (2019–2022) and is projected to develop at over 6.5% yearly from 2023 to 2032 in North America,” and since 2014, scientific analysis and shopper adoption of collagen dietary supplements have “been gaining steady curiosity,” the researchers famous.
Earlier evaluations have supported the class. Based on the authors, “two current meta-analyses of RCTs concluded that collagen dietary supplements improved pores and skin hydration and elasticity.” In distinction, their very own evaluation is the primary to seek out that funding supply and examine high quality alter the general image, main them to report no confirmed scientific profit.
Trade response
BioCell Expertise: Ingredient variability and analysis dynamics
For Douglas Jones, head of gross sales and advertising and marketing at BioCell Expertise, LLC, the examine neglected the variety of collagen sorts and formulations utilized in trials.
He advised NutraIngredients that “collagen’s a generic time period… that describes a really various and large number of totally different components,” making broad comparisons problematic.
“In lots of regards… they’re evaluating apples and oranges after they simply lump every part collectively,” he mentioned.
He additionally pushed again on the suggestion that {industry} funding compromises analysis integrity.
“Most analysis that’s carried out…on components and merchandise are carried out by the businesses that make them,” he defined, stressing that scientific trials are sometimes outsourced to impartial contract analysis organizations. “We don’t have affect.”
On scientific integrity, Jones mentioned, “the actual fact of the matter is the science is the science is the science is the science, and the info goes to be no matter it’s…typically you get an anticipated final result, and typically you don’t. I imply, that’s why scientific analysis is finished.”
CSA: Technical critique of misclassifications and knowledge errors
NI additionally spoke to the Collagen Stewardship Alliance (CSA), which targeted on the technical reliability of the meta-analysis. In its view, the paper’s conclusions about funding bias collapse underneath scrutiny as a result of the classification of {industry} involvement was usually fallacious.
For instance, Choi et al. (2014) was listed as industry-influenced regardless of having no direct funding, whereas different research with clear firm ties, corresponding to Sugihara et al. (2015) and Inoue et al. (2016), have been marked as impartial. As CSA famous, if two-thirds of “impartial” trials are actually commercially supported, then the subgroup evaluation loses its credibility.
CSA additionally documented a sequence of information reporting errors that have an effect on dose, supply and length. Yoon et al. (2014) recorded 0.75 g/day, although members really consumed 3 g.
Lin et al. (2021) reported a 50 g dose, whereas the precise consumption was nearer to five.5 g. Seong et al. (2024) reported 2.5 g/day, however the unique article solely exhibits 2 g. Even examine durations have been misstated: Bolke et al. (2019) was described as lasting 16 weeks when, actually, the intervention lasted solely 12 weeks.
Taken collectively, CSA argued, these errors not solely distort the quantitative evaluation but in addition increase questions in regards to the assessment’s total reliability.
On the problem of examine high quality, they emphasised that “industry-funded research should not essentially of decrease high quality than non-industry-funded research,” mentioning that on this meta-analysis, “the vast majority of the industry-funded research scored 3 to five out of 5” on the Jadad scale, which evaluates randomization, blinding and participant follow-up.
GROW: Framing, interpretation and the larger image
NI additionally spoke with the Gelatin Producers of the World (GROW), who took difficulty with each the framing and execution of the Myung meta-analysis. Whereas the group acknowledged that it “welcomes rigorous, impartial scientific scrutiny,” it cautioned that “this paper incorporates methodological flaws and interpretive inconsistencies that danger distorting the scientific file, deceptive readers and undermining credible analysis within the discipline.”
GROW first pointed to what it characterised as contradictory summary messaging. The summary itself, they famous, confirmed that collagen dietary supplements “present important advantages in enhancing pores and skin hydration, elasticity and wrinkles when all research are thought-about.”
But the authors later concluded that there’s “no scientific proof” to assist collagen use for pores and skin growing old, which GROW argued “creates a complicated and contradictory narrative.”
The group additionally highlighted issues in the best way the subgroup evaluation was carried out, saying it “is predicated on unclear, unpublished standards” and that “the tactic for categorizing research into ‘excessive’ and ‘low’ high quality just isn’t disclosed, nor are validated instruments (corresponding to CONSORT, Cochrane, or GRADE) used or cited.”
With out transparency, GROW maintained, “such subgroup interpretations can not function a reputable foundation for dismissing a big physique of proof.”
On the problem of funding, GROW rejected the paper’s implication that business involvement robotically undermines analysis integrity.
“Dismissing research with {industry} funding as inherently biased discredits the work of famend analysis establishments and impartial scientists,” the group acknowledged. “Funding alone doesn’t compromise scientific integrity when correct methodology and peer assessment are adopted.”
Methodological inconsistencies, GROW added, additional weaken the evaluation. It famous that a number of research labeled as ‘impartial’ (e.g., Sugihara et al., 2015; Genovese et al., 2017; Kim et al., 2018) had business affiliations.
Additionally they identified that the meta-analysis did not differentiate between pure collagen peptides and multi-ingredient blends, that the research included “differ by totally different uncooked supplies, dosage, length and topical or oral administration,” and that 17 of the 23 trials have been carried out in Asia with decrease reported every day doses (round 3 g/day) that won’t replicate world consumption patterns.
Subsequently, GROW mentioned, the assessment’s conclusions have been “drawn from small, unbalanced subgroups.”
Most significantly, GROW emphasised that the assessment doesn’t exist in isolation. Different meta-analyses, corresponding to De Miranda et al. (2021), discovered “statistically important enhancements in pores and skin hydration, elasticity and wrinkle discount, at every day doses of two.5 to 10 g of hydrolyzed collagen.” The group famous that Pu et al. (2023) and Dewi et al. (2023) likewise demonstrated “pores and skin enhancing results of collagen.”
GROW additionally concluded that “the advantages of collagen peptides for pores and skin are well known, not simply in analysis literature however by well being authorities all over the world.”
They famous that Meals Requirements Australia, Korea’s Ministry of Meals and Drug Security, Well being Canada, the Client Affairs Company Japan and the Brazilian Well being Regulatory Company (ANVISA) have formally acknowledged skin-related claims for collagen dietary supplements, lending weight to a world scientific consensus that collagen peptides are useful for pores and skin well being.
Supply: The American Journal of Drugs, 2025, ISSN 0002-9343, doi: 10.1016/j.amjmed.2025.04.034, “Results of Collagen Dietary supplements on Pores and skin Getting older: A Systematic Assessment and Meta-Evaluation of Randomized Managed Trials” Authors: Seung-Kwon Myung, Yunseo Park
