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What 2025 research actually shows
You spent €30 on collagen powder this month. According to a new meta-analysis published in The American Journal of Medicine, it probably did nothing for your skin.
But wait—there are dozens of studies showing collagen supplements improve skin hydration, reduce wrinkles, and boost elasticity. The research is everywhere. Meta-analyses confirm it. Dermatologists recommend it. Your favorite influencer swears by it.
Here's what nobody told you: when researchers filtered those studies by funding source, something remarkable happened. The effect completely disappeared.
The study that changed everything
In May 2025, researchers Seung-Kwon Myung and Yunseo Park published a systematic review analyzing 23 randomized controlled trials involving 1,474 participants. On the surface, their findings looked promising: collagen supplements significantly improved skin hydration, elasticity, and wrinkles across all studies.
Then they did something previous meta-analyses hadn't done. They separated the studies by who paid for them.
Studies not funded by pharmaceutical or supplement companies showed no effect on skin hydration, elasticity, or wrinkles. None. Studies funded by the collagen industry showed significant positive effects across all parameters.
When they filtered by study quality using standardized assessment tools, the pattern held. High-quality studies revealed no significant effect in any category. Low-quality studies showed improvements in elasticity.
Their conclusion: "There is currently no clinical evidence to support the use of collagen supplements to prevent or treat skin aging."
The collagen industrial complex
The global collagen supplement market was valued at approximately USD 5.91 billion in 2025 and is projected to reach USD 8.02 billion by 2030, according to Mordor Intelligence market analysis. That's a lot of powder.
Much of this market rests on research conducted by—or funded by—the companies selling the products. One major player is GELITA AG, a 150-year-old German manufacturer that produces branded collagen peptides like VERISOL for skin and FORTIBONE for bones.
Look through the clinical trials on collagen, and you'll see the same pattern. Studies testing VERISOL products. Research by the same group of investigators. Funding disclosures noting lectures "supported in parts by GELITA AG" or researchers who are "co-inventors of patents concerning the use of collagen peptides."
This does not imply misconduct—industry-funded research is standard practice across pharmaceutical and supplement sectors, and researchers typically follow rigorous protocols regardless of funding source. The concern arises when independent studies systematically fail to reproduce the positive effects found in company-sponsored research, suggesting the funding source itself may influence outcomes through publication bias, study design choices, or selective outcome reporting.
The anatomy of a collagen study
Take the Bolke 2019 study, published in Nutrients. It tested ELASTEN, a drinkable supplement by QUIRIS Healthcare containing 2.5g collagen peptides plus vitamin C, zinc, biotin, and vitamin E. The study found significant improvements in skin hydration, elasticity, roughness, and density.
The authors declared no conflict of interest. But they worked for Dermatest GmbH, a contract testing laboratory. The product contained multiple active ingredients, not just collagen. And the placebo contained no nutrients at all—not even the vitamins and minerals that might affect skin on their own.
This is the methodological gray zone where much collagen research lives. Not fraudulent, but not exactly rigorous either. Multiple active ingredients make it impossible to know what's working. Industry connections create inherent bias even with the best intentions. Small sample sizes and short durations limit generalizability.
What about all those other meta-analyses?
If you search PubMed for meta-analyses on oral collagen supplementation, you'll find several published between 2021 and 2023. Most conclude that collagen supplements improve skin parameters. The Pu 2023 meta-analysis of 26 RCTs found significant improvements in both hydration (Z = 4.94, p < 0.00001) and elasticity (Z = 4.49, p < 0.00001).
So who's right?
They're analyzing the same studies. The Myung analysis doesn't contradict earlier meta-analyses—it adds a crucial filter they didn't use. Previous reviews pooled all available RCTs together without accounting for who funded them or how well they were designed. Myung separated the wheat from the chaff.
When you look at the full body of evidence without filters, collagen appears to work. When you filter by funding source and study quality, the effect vanishes. Both findings can be true simultaneously. The question is which one reflects reality.
The industry strikes back
The Collagen Stewardship Alliance, an industry group, has criticized the Myung analysis. They claim the study misclassified funding sources, putting some industry-funded trials in the "independent" category and vice versa. They point to data reporting errors: wrong doses, incorrect study durations, misreported sample sizes.
If true, these are legitimate methodological concerns. But they also reveal how invested the industry is in defending these findings. The CSA's argument essentially admits that funding source matters—otherwise, why fight so hard about the classification?
Douglas Jones of BioCell Technology told NutraIngredients: "Most research that is done on ingredients and products are done by the companies that make them. We don't have influence. The science is the science."
Perhaps. But when independent research finds no effect and company-funded research finds significant effects, at minimum it suggests we need more independent research before spending billions on a product category.
The biological plausibility problem
Setting aside funding bias, there's a fundamental question: does it even make sense that oral collagen would improve your skin?
When you eat collagen peptides, your digestive system breaks them down into amino acids—the same amino acids you'd get from eating chicken, fish, or beans. Some research suggests small collagen peptides (dipeptides and tripeptides) can be absorbed intact and detected in blood. Whether they specifically travel to your skin and rebuild collagen there is another question entirely.
The body produces collagen from amino acids along with vitamin C, zinc, copper, and manganese. You can get all of these from food. The theoretical advantage of collagen supplements over, say, a piece of salmon and some vegetables remains unclear.
Animal studies in hairless mice show oral collagen peptides may reduce UV-induced skin damage and improve moisture. But hairless mice aren't humans. The extrapolation requires a leap of faith—or more human trials that aren't funded by collagen manufacturers.
What this means for you
If you've been taking collagen supplements and feel your skin looks better, this article isn't here to tell you you're wrong. Placebo effects are real, and if something makes you feel better, that has value. Collagen supplements are generally considered safe with few reported side effects.
But if you're considering starting collagen supplementation based on the research, here's what you should know: the clinical evidence supporting its use is almost entirely funded by the companies selling it. When researchers account for this bias, the evidence for efficacy disappears.
For €30 per month, you could instead:
- Use a prescription retinoid (tretinoin or adapalene), which has decades of independent research showing it improves skin texture and wrinkles
- Invest in daily broad-spectrum sunscreen, which prevents the collagen degradation that leads to aging in the first place
- Eat a varied diet with adequate protein and micronutrients
- Save the money
The uncomfortable question isn't whether collagen supplements work—it's whether we've collectively spent billions on a product whose primary evidence base is its own marketing.
Belgium/EU Availability
Collagen supplements are widely available in Belgian pharmacies, health stores, and online retailers without prescription. Here's what you'll typically find:
Common brands and pricing:
- Etixx Collagen Complex (300g powder): €32.99 - Contains FORTIGEL and TENDOFORTE (GELITA products), vitamin C. Marketed for sports/joint support.
- Collavita (Belgian brand, Bredene): €30-40 per container - Available in Belgian pharmacies, marketed for skin/joints/sport
- PharmaMarket collagen supplements: €21.45-29.95 - Various formulations with vitamin C, hyaluronic acid
- Vitaminstore.nl (Netherlands): €20-35 for most products - Types I and II collagen, various brands
- Generic collagen powders: €15-25 for 250-300g
What to note:Most products contain additional ingredients beyond collagen (vitamin C, hyaluronic acid, chondroitin, biotin), making it impossible to isolate collagen's specific effects—the same methodological problem that plagues the research.
Many Belgian products prominently feature GELITA brand ingredients (FORTIGEL, TENDOFORTE, VERISOL)—the same company whose funded research shows positive effects while independent research shows none.
EU regulatory status:Collagen supplements are classified as food supplements, not medicines. This means:
- No requirement to prove efficacy before sale
- Claims must be limited to approved EU health claims (e.g., "vitamin C contributes to normal collagen formation")
- Cannot claim to treat or prevent diseases
- No prescription needed
The permitted claims focus on vitamin C's role in collagen formation—not on whether consuming collagen peptides improves your skin. This regulatory nuance is easy to miss in marketing materials.
If you're set on trying collagen despite the evidence:
- Expect to spend €25-35 per month for typical dosing
- Look for products with third-party testing (rare in this category)
- Be skeptical of dramatic before/after claims
- Remember that the independent research shows no effect
Better-evidenced alternatives available in Belgium:
- Tretinoin (prescription): Available as magistrale bereiding (compounded) through Belgian pharmacies, €15-25 for 30g
- Adapalene (Differin, 0.1%): Available OTC in some EU countries, check Belgian pharmacies
- Sunscreen: The single best anti-aging intervention, €10-20 for quality product
- Vitamin C serums (topical): Some evidence for skin benefits when properly formulated, €15-30
This is Episode 2 of our Evidence vs. Marketing series, where we examine what 2025 research actually shows about popular skincare ingredients and devices. Coming next: LED Masks—Science or Theater? When does light therapy actually penetrate?