Abstract
A recent meta-analysis by Myung & Park (2025) claims there is “no clinical evidence” that oral collagen supplements help aging skin[1][2]. This bold conclusion is based on subgroup analyses suggesting that collagen only works in industry-funded or lower-quality trials, disappearing in independent or high-quality studies[3]. However, a closer examination reveals several methodological issues in that review, including a very small number of truly independent trials (many of which used suboptimal doses and durations) and the dismissal of positive findings from rigorous studies.
When collagen is tested under appropriate conditions – adequate dosage (≈5 g daily), sufficient duration (12–16 weeks or more), and robust methodology – significant skin benefits do emerge. For example, a 16-week randomized, placebo-controlled, double-blind trial (RCT) (Žmitek et al., 2024) found that 5 g/day of collagen (with vitamin C) led to measurable improvements in dermal density, skin texture, and wrinkle depth[4]. While not a panacea (it did not alter skin hydration or elasticity[4], as expected), collagen supplementation under the right conditions can support skin structure. In sum, it is premature and unscientific to dismiss collagen supplements entirely. The evidence indicates that collagen’s efficacy depends on study quality, dose and duration – not merely on who funded the research. Science should focus on rigorous data, not blanket generalizations, and the latest high-quality studies (including the independent studies, funded by TOSLA Nutricosmetics) demonstrate that collagen can indeed improve aspects of skin aging when properly dosed.
Key Claims of the Myung & Park (2025) Meta-Analysis
Myung and Park conducted a systematic review and meta-analysis of 23 randomized controlled trials (total n = 1,474) on collagen supplementation for skin aging[5]. At first glance, their aggregated results were actually positive: across all 23 RCTs, collagen supplementation produced statistically significant improvements in skin hydration, elasticity, and wrinkles compared to placebo[5]. These findings are consistent with several earlier reviews that reported collagen peptides can enhance skin moisture and elasticity and reduce wrinkle depth in aging skin. However, the controversy arose from the authors’ additional analyses:
- Funding Source Subgroup: When the trials were divided based on funding, those “not receiving funding from pharmaceutical companies” showed no significant benefit from collagen, whereas trials with pharmaceutical funding did show significant improvements[3]. In other words, the meta-analysis reported that collagen’s efficacy vanished in studies without industry backing. This led the authors to insinuate that positive outcomes might be due to industry bias.
- Study Quality Subgroup: Similarly, when pooling only the “high-quality” trials (as judged by risk-of-bias tools or Jadad score), the benefits of collagen allegedly disappeared for all skin parameters[6]. In contrast, the lower-quality studies did show some benefits (significantly improved elasticity in that subset)[6]. This dichotomy again casts doubt on the validity of collagen’s effects, suggesting that only less rigorous trials found positive results.
- Headline Conclusion: Based on these subgroup analyses, Myung & Park conclude “there is currently no clinical evidence to support the use of collagen supplements to prevent or treat skin aging”[1][7]. This sweeping statement – effectively negating all prior positive findings – is what grabbed headlines and sparked debate in dermatology and supplement circles.
In summary, the Myung & Park paper asserts that once potential industry bias and study flaws are accounted for, collagen supplements show no real anti-aging benefit for skin. This is a strong claim that warrants careful scrutiny, especially given that the overall data (and many dermatologists’ experience) suggest collagen can improve at least some skin metrics. Below, we critically examine the meta-analysis methodology and explain why its conclusions are not as definitive as they appear.
Scrutinizing the Meta-Analysis Methodology
Several issues in the meta-analysis’s design and interpretation raise questions about the “no benefit” conclusion. Key points of critique include:
Limited Truly Independent Trials
Out of the 23 RCTs analyzed, only a handful (around six or so) were reported as having no pharmaceutical company funding. In reality, the distinction between “funded” and “non-funded” studies in this meta-analysis is blurred – 21 of the 23 trials had some form of industry involvement[8]. Notably, several studies classified as “non-funded” were sponsored by collagen ingredient manufacturers (just not large pharmaceutical companies). For example, Sugihara et al. and Inoue et al. were internal R&D studies by a gelatin manufacturer, and other trials labeled independent had industry support disclosed in their original papers[9]. Truly independent research (e.g. funded by universities or public grants) is exceedingly rare in nutraceuticals, and this meta-analysis simply didn’t have a robust sample of purely independent trials to justify the claim that “collagen only works in industry-funded studies.” In short, the subgroup analysis by funding source rests on very thin evidence – potentially comparing 17 industry-funded studies to as few as ~6 non-industry studies, many of which were very small. Any apparent lack of effect in the “independent” subset must be interpreted with caution due to this low sample size and misclassification of funding. It does not prove that independence causes a lack of efficacy.
Collagen Dose Matters – and Many Trials Used Modest Amounts
A critical factor in supplementation trials is whether the dosage is sufficient to elicit a biological effect. Many of the putatively “independent” studies in the meta-analysis used relatively low daily collagen doses (in the range of 1–2.5 grams per day). While this is below the ~5 g/day dose that many experts consider a minimum for consistent clinical efficacy in skin aging, it’s worth noting that even these modest amounts showed some promising results. For instance, one trial by Kim et al. included in the meta-analysis gave only 1 g of collagen per day[10], and another by Sugihara et al. used 2.5 g/day[11] – yet both reported skin improvements, suggesting that lower doses may still offer benefits, potentially requiring more time or yielding subtler effects. It’s reasonable to suspect that such low doses might produce only mild effects or inconsistent results, which could skew a subgroup analysis. By contrast, most larger positive trials in the literature have used around 5 g of collagen peptides daily (some even 10 g). If four of the six “independent” trials were under-dosed (1–2.5 g), it’s not surprising that their outcomes were modest. In essence, the meta-analysis may be partially conflating dose effects with funding: the independent studies tended to use lower doses (perhaps due to limited budgets or pilot nature), whereas industry-sponsored studies often provided higher doses (to maximize chances of success). Thus, the lack of effect in the “non-funded” category may simply reflect inadequate dosing, not an inherent ineffectiveness of collagen. A fair analysis would control for dosage in some way (e.g. a dose-response analysis), but Myung & Park did not explicitly do so.
Duration of Treatment – 8 Weeks Is Likely Insufficient
Another important consideration is treatment duration. Skin collagen remodeling is a slow process; it can take collagen peptides several weeks to be incorporated into new dermal tissue and for measurable changes (like wrinkle reduction or dermal density increases) to occur. Many dermatologists consider 12 weeks (3 months) a more appropriate minimum trial duration for anti-aging outcomes, with some studies extending to 16 or 24 weeks for robust results. Yet, a number of RCTs in the meta-analysis – including some of the “independent” ones – lasted only 8 weeks[12][13]. For example, Sugihara et al. (2.5 g collagen) and Inoue et al. (2 g collagen) both ran just 8-week interventions, which is barely two skin cycles. Unsurprisingly, very short trials may not capture the full effect of collagen supplementation, especially on deeper skin layers. An 8-week study might show improvements in skin hydration (a superficial parameter) but not yet detect significant wrinkle reduction or dermal thickening, which develop more gradually. This is a known issue – prior meta-analyses have noted that the beneficial effects of collagen become more pronounced at 12 weeks and beyond. By pooling 8-week and longer studies together without adjusting for duration, and then highlighting that some short, independent studies saw no effect, the meta-analysis again risks a skewed interpretation. The dermal regeneration window is simply longer than two months. Thus, the “many were too short” criticism is quite pertinent: several null-result studies may have failed to run long enough to allow collagen’s mechanisms (e.g., stimulating fibroblasts to lay down new collagen) to translate into visible clinical improvements.
Treatment of High-Quality Positive Studies
Perhaps the most concerning aspect is how the meta-analysis handled studies that were both high-quality and showed strong positive results. One would think these are the most important trials to pay attention to. Yet Myung & Park’s approach effectively down-weighted or discarded some of these data. They report performing a sensitivity analysis in which they excluded “outlier” trials that showed extremely beneficial effects of collagen[14]. After removing these outliers, the pooled effect on wrinkles became non-significant, and the effects on hydration and elasticity were diminished[14]. While it’s valid to check that no single study is unduly influencing the meta-analysis, labeling the best-performing studies as statistical outliers can be problematic – it begs the question of why those studies found such marked benefits. In at least two cases, the “outlier” trials were likely well-designed studies using proper collagen doses that did, in fact, demonstrate significant improvements in skin aging markers. Instead of exploring the reasons behind their success (e.g., superior methodology, sufficient dose/duration, or more sensitive outcome measures), the meta-analysis essentially dismissed their results to see if the overall significance would go away. This approach can introduce bias: one could always drop the most favorable trials and be left with a null result. A balanced analysis should consider all high-quality evidence. By ignoring the positive high-quality trials (because they happened to be industry-sponsored or had larger effect sizes), the authors tilted the scales toward a negative conclusion. It’s worth noting that publication bias was also assessed in the meta-analysis and some asymmetry was found (suggesting smaller studies without effects might be under-reported)[15]. But after adjusting for this, the authors still circle back to the funding/quality issue as the crux. In our view, this all means the meta-analysis’ conclusions rest heavily on how one interprets a few studies and analytical choices, rather than a consistent pattern of collagen failing under rigorous testing.
In summary, the Myung & Park meta-analysis is not wrong to investigate funding bias or study quality – these are important considerations in any literature. However, the way the data were handled and presented appears to have overcorrected for potential bias and, in the process, undercut legitimate findings. The result was a headline-grabbing conclusion that isn’t fully supported by the underlying evidence. We argue that a more nuanced interpretation is needed: collagen’s efficacy has been demonstrated in multiple trials, but results vary depending on dosage, duration, and endpoints measured. The real lesson is to design better trials, not to proclaim the entire concept ineffective due to the funding source. To reinforce that point, we turn to a recent research study as a case study in the rigorous evaluation of collagen for skin health.
Evidence from 16-Week RCT (Žmitek et al., 2024) funded by TOSLA Nutricosmetics
To address some of the shortcomings in the existing literature, our R&D team at TOSLA Nutricosmetics collaborated with academic partners to conduct an independent, randomized, double-blind, placebo-controlled trial on collagen supplementation. This trial (Žmitek et al., published in Nutrients in 2024) was one of the most comprehensive to date, and its design specifically aimed to meet the high-quality criteria discussed above:
- Study Design: 87 healthy women, ages 40–65, were enrolled and randomly assigned to one of three groups for 16 weeks: a placebo group, a collagen + vitamin C group, and a collagen + vitamin C + hyaluronic acid group[16][17]. The study was randomized, double-blinded, and placebo-controlled, meaning neither the participants nor the investigators knew who received collagen vs. placebo until the end. This eliminates expectation bias and meets the gold standard for trial quality. The intervention products were produced under GMP conditions by TOSLA Nutricosmetics (ensuring a high-quality, tested collagen peptide ingredient), while the placebo was a sensorially matched formula without active collagen.
- Dosage and Ingredients: The daily dose used was 5 grams of hydrolyzed collagen peptides (bovine-derived type I collagen) combined with 80 mg of vitamin C[18][17]. Five grams was chosen based on prior evidence that this dose is clinically effective for skin outcomes. Vitamin C was included because it is a co-factor for collagen synthesis in the skin and may synergize with collagen peptides. In one of the test groups, 30 mg of hyaluronic acid (a component known for skin hydration) was additionally included to see if it would enhance outcomes[16]. Notably, 5 g collagen + 80 mg vitamin C reflects a clinically relevant dose far above the under-dosed studies in the meta-analysis. The 16-week duration is also double the length of those 8-week trials, aligning with the expected timeframe for dermal changes.
- Outcome Measures: An extensive battery of objective skin measurements was performed at baseline, 8 weeks, and 16 weeks. Key endpoints included dermis density and thickness (measured by ultrasound imaging of the skin), skin surface parameters like roughness/smoothness and wrinkle depth (measured by 3D skin replicas and optical profilometry), as well as skin hydration, elasticity, and transepidermal water loss (TEWL) (measured by corneometry, cutometry, etc.)[18][4]. By covering both deep structural changes and superficial skin properties, the aim was to get a complete picture of collagen’s effects. Importantly, these methods were all validated instrumentation techniques, ensuring reliable, quantifiable data (as opposed to just subjective questionnaires).
- Results – Skin Structure Benefits: After 16 weeks, the collagen-supplemented groups showed statistically significant improvements in several markers of skin structure and appearance compared to the placebo. In particular, the researchers observed notable enhancements in dermis density and skin texture, along with a measurable reduction in the severity of wrinkles in the collagen groups[4]. For example, ultrasound scans revealed an increase in dermal density (indicating new collagen deposition or improved matrix organization) in the collagen-supplemented participants. Likewise, 3D skin replica analysis showed that wrinkle depth and volume (especially around the eyes) decreased significantly in the collagen groups versus placebo. Skin roughness (the micro-texture of skin) also improved, meaning the skin surface became smoother due to collagen. These findings directly support the notion that oral collagen can strengthen the dermal matrix and reduce visible signs of aging, like wrinkles – consistent with many earlier individual studies.
- Results – Hydration and Elasticity: Interestingly, and in line with physiological expectations, the researchers did not observe significant changes in skin hydration or elasticity in the collagen-treated subjects (relative to placebo)[4]. Both hydration (measured as moisture content of the stratum corneum) and elasticity (measured by the skin’s rebound to deformation) remained statistically similar to controls. Why is this unsurprising? Collagen peptides mainly integrate into the dermal collagen network or trigger dermal fibroblast activity. This leads to improvements in the structural aspects of the skin (density, firmness, wrinkle reduction) rather than immediate changes in how the epidermis retains water or how elastic fibers function. Hydration of the skin is largely governed by epidermal lipids, natural moisturizing factors, and hyaluronic acid content – factors that a collagen supplement alone may not influence in a short timeframe. Similarly, skin elasticity depends not just on collagen but also on elastin fibers and hydration; it might require a longer time or additional interventions to improve. The results align with this understanding: oral collagen’s primary benefits lie in fortifying the dermis (thus reducing wrinkles and improving firmness), rather than superficially moisturizing the skin. Notably, some other trials have reported modest gains in skin hydration or elasticity with collagen, but those effects are variable and not as consistently seen as the wrinkle and density improvements. The trial’s hydration/elasticity null result is therefore not a failure, but a reflection of collagen’s specific role – something the meta-analysis conclusion overlooked by expecting “no effect = no value,” whereas in truth, collagen has targeted benefits.
- Results – Role of Hyaluronic Acid: The researchers also tested whether adding hyaluronic acid (HA) to the collagen formula would yield additional benefits. At 30 mg/day of HA (a typical oral dose, meant to support skin moisture from within), they found no significant difference between the collagen+Vitamin C group and the collagen+Vitamin C+HA group[19]. Both groups improved similarly in dermal metrics, and neither showed hydration changes, suggesting that the HA dose and duration in this context did not measurably augment the outcome. In practical terms, this means collagen peptides were the main active ingredient responsible for the benefits seen; adding a small HA supplement didn’t provide an extra boost in the measured parameters. It’s a useful finding for product formulation, but more broadly, it underscores that collagen alone (with vitamin C) was effective in improving skin structure over 16 weeks.
- Study Quality and Independence: It’s worth highlighting that the RCT was conducted to the highest standards of quality. It was a preregistered, peer-reviewed study published in an international journal (Nutrients). The research was a collaboration between an academic institute and our company’s R&D, with partial funding from both a government research agency and TOSLA Nutricosmetics (legal company name Tosla d.o.o.)[20]. Importantly, as disclosed in the publication, the industry funder (TOSLA Nutricosmetics) was not involved in the study design, data collection, analysis, or interpretation, nor in the writing of the paper[20]. TOSLA’s role was limited to providing the collagen product and financial support, while the scientific work was overseen by independent researchers. This model ensured the objectivity and credibility of the results. We mention this to demonstrate how industry support can be combined with rigorous methodology: the trial had a low risk of bias on all counts (randomization, blinding, placebo-control, predefined outcomes, etc.). In fact, a number of authors on the paper are from independent institutions (a cosmetics science institute and a dermatology clinic). By all measures, this was a high-quality study – exactly the kind that should inform meta-analyses going forward. And its positive findings stand in direct contrast to the notion that “high-quality studies show no effect.” This study was high-quality and did show effects (in dermal density, wrinkles, etc.). This is a strong counterpoint to the meta-analysis’ implication that collagen’s benefits evaporate under rigorous examination.
In summary, the Žmitek et al. (2024) trial provides concrete evidence that when collagen supplementation is done right – using a proper dose, for long enough, and measuring the right outcomes – significant skin anti-aging benefits can be demonstrated. It bridges the gap between industry and independent science by using transparent methods with industry support, yielding trustworthy data. This adds to the growing body of robust collagen research and helps refute the claim that collagen’s observed benefits are merely artifacts of biased or poor studies.
Funding Source vs. Study Quality: Interpreting Bias in Collagen Research
A core debate triggered by the 2025 meta-analysis is whether industry sponsorship invalidates collagen research results. It’s true that industry-funded studies are sometimes viewed with skepticism, as there is a known phenomenon across medical research where sponsored trials more often report positive outcomes favorable to the sponsor. However, it is critical not to paint with too broad a brush. Funding source alone is a blunt criterion to judge a study’s credibility – what matters more is the study’s methodological rigor and transparency. Here are some key perspectives on funding vs. quality in the context of collagen:
Industry Funding is Common – and Compatible with High Quality
In the field of nutraceuticals (and dermatology supplements in particular), the vast majority of research is funded by industry simply because there are few public grants for these topics. Collagen trials often require specialized materials and assessments that companies provide. As noted, in Myung & Park’s own dataset, 21 of 23 studies had some industry input[8]. Importantly, many of the best-designed collagen trials are industry-funded. Having a sponsor does not automatically make a study low-quality. In fact, an analysis of the trials in the collagen meta-analysis shows that about 80% of the studies rated as high-quality (Jadad score 5/5) were industry-funded[21]. This aligns with the general observation that well-resourced studies (often funded by companies) can achieve excellent methodological standards – for example, they can afford larger sample sizes, longer durations, and advanced measurement techniques. Thus, it would be a mistake to assume “industry-funded = biased & unreliable” in every case. Each study must be assessed on its own merits (randomization, blinding, objective outcomes, peer-review, etc.), regardless of who paid for it. As long as there is full disclosure of funding and any conflicts of interest (which reputable journals now mandate) and the study design is solid, the data should be considered at face value.
Safeguards and Transparency
Good scientific practice includes safeguards to minimize bias even when industry is involved. For instance, in the above-mentioned trial, the sponsor provided the product but had no role in data analysis or reporting[20]. Many other collagen studies follow similar practices – outsourcing measurements to independent labs, using third-party statisticians, or publishing through academic partnerships. Moreover, all participants in the research (including industry scientists) typically adhere to standard protocols that are scrutinized during peer review. The presence of a company’s support does not mean researchers will fabricate data; doing so would destroy reputations and can be detected in peer review or follow-up studies. It’s also worth noting that several collagen studies are published in high-quality journals and go through rigorous peer review, further ensuring that the findings are credible. In short, methodology and integrity determine reliability, not the logo on the funding check.
Bias vs. Truth – the Balance of Evidence
The meta-analysis rightly raises the point that if one restricts the analysis to independent trials, collagen’s effects were not significant. But as we discussed, that independent set was tiny and plagued by other issues (low dose, short duration). It is not a representative or sufficiently powered sample to settle the question. The totality of evidence, including larger sponsored trials and now some independent ones as well, does indicate collagen has real effects on skin physiology. It’s prudent to be wary of bias, but equally, one must be wary of throwing out valid results simply because of who obtained them. A blanket dismissal of all industry-associated research on collagen would mean disregarding most of what we know about this supplement. Such an approach would halt progress and insight. Instead, the better path is to demand high standards from all studies (whether funded by industry or not) – pre-register the trial, publish detailed methods, share data when possible, and replicate findings. Over time, if an effect is real, multiple studies by different investigators (including some independent ones) will demonstrate it. We are starting to see this with collagen: academic interest is growing and more independent trials are being done or planned, precisely to verify the earlier industry-led findings.
Understanding “No Effect” Outcomes
It’s also instructive to analyze why some high-quality studies might not find effects. A null result doesn’t automatically mean the product doesn’t work; it could be due to an insensitive measurement, a specific population that didn’t respond, or simply statistical chance in a smaller sample. For example, one independent trial (Guadanhim et al. 2017 in Brazil, university-funded) gave 5 g of collagen for 6 months and found no benefit on the forearm skin of older women[22][23]. Does this single negative result nullify all positive ones? Unlikely – rather, it suggests collagen might have a limited effect in certain conditions (dermatoporosis in forearm skin), or that the sample size (53 people) wasn’t enough to reach significance for the subtle changes. In contrast, numerous other trials in facial skin did see improvements. Science must synthesize all available data, weighing each study by its quality and context, to reach a consensus. The meta-analysis by Myung & Park attempted this, but as we’ve shown, their approach to weighting quality and funding skewed the picture. A more balanced view recognizes that some high-quality trials show clear benefits, some show none, and many low-to-moderate quality trials show benefits – the logical interpretation is not that collagen doesn’t work, but that results vary and we need to understand why. It could be related to formula differences, genetic differences in participants, or measurement techniques. Dismissing the positive outcomes as bias is one interpretation, but an equally (if not more) plausible interpretation is that the conditions under which collagen works best need to be defined.
To sum up, funding source should not be the lone litmus test for truth. Robust science can come from industry-backed studies, and conversely, an independently funded study can be poorly designed or underpowered. The focus should shift away from “who funded it?” toward “how well was the study done, and what do all the data show?”. In the case of collagen, when we examine the full landscape – industry and independent studies together – we find a converging narrative that collagen supplementation can improve certain aspects of skin aging (especially wrinkles and dermal composition), even if results aren’t uniform across every trial. The call to action is for more research, ideally with collaborations between academia and industry to leverage the strengths of both. Indeed, as noted in one commentary, “funding, on its own, doesn’t invalidate good research”[21]. Many high-quality nutraceutical trials are funded by product companies and that’s perfectly fine so long as methods are sound and disclosures are made[21]. We have demonstrated this principle in our own work.
Conclusion
The 2025 meta-analysis by Myung & Park stirred the pot by suggesting collagen supplements are useless for skin aging unless you believe biased industry studies. However, our critical review finds that this conclusion is overstated and premature. Yes, the meta-analysis rightly points out the need for cautious interpretation of industry-led research and the importance of high methodological quality. But it went a step too far in concluding “no clinical evidence” exists for collagen’s benefits[1][7]. In fact, when all data are considered, there is credible evidence that oral collagen can improve skin parameters, with the caveat that not all studies show it, especially those that may be underdosed or too brief.
To put things in perspective:
- Even Myung & Park’s own pooled data showed significant improvements in wrinkles, elasticity, and hydration from collagen[5], aligning with prior meta-analyses and dozens of RCTs before them. This should not be swept under the rug. Collagen’s efficacy signal is there in the literature – it’s not a mirage. The appropriate response is to investigate why some analyses weaken that signal, not to declare the signal null.
- Dose and Duration are Key: The weight of evidence indicates that around 5 g/day of hydrolyzed collagen for at least 8–12 weeks is typically needed to observe skin benefits. Trials that meet these criteria more consistently report positive outcomes. Lower doses (1–2 g) or very short trials (4–8 weeks) often yield less impressive or no results, which is unsurprising for any intervention. This dose-duration dependency is a common theme in nutrition research and must be acknowledged when judging efficacy. Dismissing collagen because some tiny trials showed no effect is like dismissing a medication that was never given at a high enough dose to work.
- Appropriate Outcome Measures: It’s also crucial to measure the right things. Collagen is most likely to affect the dermal extracellular matrix, so outcomes like dermal density (via ultrasound or MRI), biomechanical skin properties, and wrinkle morphology are directly relevant. Outcomes like short-term stratum corneum hydration or even elasticity might not change much with collagen alone, which doesn’t mean collagen “failed” – it means its action is specific. Aligning expectations with the mechanism leads to better interpretations. For instance, the RCT in TOSLA Nutricosmetics funded studies found no change in hydration or elasticity, yet it is considered a success because it confirmed significant improvements in dermal structure and wrinkles[4]. A blanket statement of “no effect on skin” would ignore these targeted benefits.
- Study Quality and Bias: We fully agree that well-designed, placebo-controlled, double-blind, randomized trials are the gold standard. Future collagen research should continue to uphold high quality (whether funded by industry or government, or both). The conversation should shift from “collagen doesn’t work” to “which collagen works, at what dose, for whom, and measured how?”. It’s a more nuanced question, but a far more scientifically productive one. The meta-analysis attempted to answer a simpler yes/no question and, by over-focusing on funding, likely oversimplified a nuanced reality. Funding alone is not destiny – rigor is. With more stringent trials coming out (such as the above-mentioned 2024 Nutrients study and other recent independent studies), the scientific community will be able to make a more informed judgment. Early signs suggest that these rigorous studies are corroborating collagen’s benefits rather than refuting them.
In conclusion, pronouncing collagen supplements ineffective for skin aging is not justified by the total evidence at hand – it is an overreach that could mislead consumers and practitioners. A fair assessment is that collagen can be effective, provided it’s used in the right form, dose, and duration, and studied with the right methods. Rather than dismissing the whole category, the field should focus on refining research and recommendations: for example, establishing standard protocols for collagen trials, understanding responder vs. non-responder differences, and exploring combination approaches (collagen with other nutrients) in a scientific way.
Collagen peptide supplementation remains a promising, evidence-backed strategy for improving aspects of skin aging[24], and it would be premature and unscientific to close the book on it based on an arguably flawed meta-analysis. The evidence-based perspective is one of cautious optimism: acknowledge the limitations and potential biases, but also recognize the positive outcomes demonstrated in multiple studies. By doing so, we encourage continued rigorous research and a nuanced view that serves both science and the public. In the end, skin health is a complex puzzle – collagen is one piece of it, and when used appropriately, it appears to be a meaningful piece rather than a placebo.
References
- [1] [8] [9] [21] [24] Is It True That Collagen Supplements Don’t Work for Your Skin? – CHOSEN Store
- https://chosenstore.in/blogs/blog/collagen-supplements-2025-meta-analysis-review?srsltid=AfmBOorIAO2spE6d84t9-tJlhILhczrtCiDIzE7KN0BbixxaLRo8ZsSB
- [2] [3] [5] [6] [7] Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials – PubMed
- https://pubmed.ncbi.nlm.nih.gov/40324552/
- [4] [16] [17] [18] [19] [20] 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 – PubMed
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- https://www.amjmed.com/article/S0002-9343%2825%2900283-9/abstract