Collagen Powders Promise Younger Skin. The Independent Trials Say Otherwise

Collagen has become one of the best-selling supplements in the country, stirred into morning coffee and sold in tubs that promise firmer, smoother skin. The idea is intuitive. Collagen is the main structural protein in skin, the body makes less of it with age, so swallowing more should help.

The research has looked supportive for years. Several meta-analyses, which pool results from many trials, concluded that collagen improves skin hydration and elasticity. A 2025 analysis asked a sharper question and got a very different answer.

What the new analysis did

Researchers publishing in The American Journal of Medicine¹ gathered 23 randomized controlled trials involving 1,474 participants, all testing oral collagen against a placebo for signs of skin aging.

Combined, the results looked good for collagen. Supplements were linked to improvements in hydration, elasticity and wrinkles.

Then the researchers split the studies two ways. First by who paid for them, and second by how well they were designed.

In trials without industry funding, collagen showed no significant effect on any outcome. In trials rated as high quality, it also showed no significant effect. The benefit appeared in industry-funded studies and, for elasticity, in lower-quality ones. The authors concluded there is currently no clinical evidence to support collagen supplements for preventing or treating skin aging.

The industry response

Supplement trade groups pushed back quickly. As reported by NutraIngredients², they argued that industry funding does not automatically make research biased, that several studies were placed in the wrong funding category, and that the analysis lumped together very different products, from pure collagen peptides to multi-ingredient blends.

Some of those critiques have merit. Funding source is not proof of bias, and well-designed industry trials exist. Pooling products with different doses and sources is a genuine weakness.

But the pattern the analysis found is a familiar one in nutrition research. When positive results cluster in sponsored studies and fade in independent ones, the reasonable response is caution. A review by the American Council on Science and Health³ noted that even earlier positive analyses shrank considerably once the most extreme results were set aside, and that some elasticity benefits appeared only with particular measurement methods.

Does swallowed collagen reach the skin?

Collagen is a protein. Like other proteins, it is broken down during digestion into amino acids and small chains of amino acids called peptides. Supplement makers point to research suggesting certain peptides reach the bloodstream and may signal skin cells to make more collagen. That mechanism is plausible but unproven in people, and the body also makes collagen from protein in ordinary food such as meat, fish, eggs, dairy and beans.

How to read the next collagen headline

New collagen studies appear regularly, and many are announced by the companies that paid for them. A few questions help sort them. Was the trial randomized and compared with a placebo? How many people took part, and for how long? Who funded it, and did the funder help analyze the data? Were the skin measurements made by someone who did not know which group each person was in? Small, short, sponsored trials with soft outcomes are the ones most likely to overstate a benefit.

What has strong evidence

If the goal is skin that ages more slowly, the strongest evidence still points to the basics we have covered before. Daily broad-spectrum sunscreen of SPF 30 or higher, which the FDA describes⁴ as reducing the risk of early skin aging when used as directed along with other sun protection, is the single most effective step. We explained why in our story on sunscreen as the best anti-aging product.

Topical retinoids come next, with decades of trials showing they improve fine wrinkles and texture. Our guide to climbing the retinoid ladder covers how to start without irritation. Not smoking matters too.

Should you stop taking it?

Collagen supplements appear safe for most people, so this is mostly a question of money. A month's supply can easily run tens of dollars. People with allergies to fish, shellfish or eggs should check the source, since collagen is often made from marine or other animal products. Like all supplements, collagen is not reviewed by the FDA for effectiveness before sale.

If you enjoy a collagen drink and the cost does not matter to you, there is little harm in continuing. If you are choosing where to spend a limited skin care budget, the evidence says sunscreen and a retinoid will do far more.