The Truth About Collagen in Skincare

Collagen may just be one of the longest-lived trends in the beauty industry. Most of us know just enough about collagen to know that it’s important, and many of us assume that, since collagen is everywhere, there must be something to it, right?

beautiful woman in water
Spoiler: She doesn’t look like this because of collagen cream.

The problem is that these same companies stand to make a LOT of money off of anti-aging products that look and sound clinical. There’s a reason that so many creams and supplements have bare-bones, muted, prescription-style packaging: We naturally tend to trust things that look and sound pharmaceutical.

The truth is that collagen as a skincare or supplement ingredient does have its merits, but it is NOT the elasticity-restoring Fountain of Youth that most products make it out to be.

Collagen in Skincare: The 500 Dalton Rule

There is one particular study that is cited in just about any article you might see about collagen in skincare. It talks about the 500 Dalton Rule, which essentially says that any molecule heavier than 500 daltons is completely unable to penetrate the skin.

A dalton is simply how scientists measure the molecular weight of a protein, and 500 daltons is currently the upper limit of what we know will penetrate our skin’s barrier. In general, collagen molecules can range anywhere from 15,000-50,000 daltons, which is WAY beyond that limit.

There are no topical medications that have been effective much above 500 Daltons, nearly all known allergens are less than 500 Daltons, and the most commonly used pharmaceuticals agents are below 500 Daltons. (source)

This means that there is no way for the collagen in your creams, serums or sheet masks to get anywhere near the deeper layers of tissue and actually boost the amount of natural collagen in your skin.

FutureDerm affirms this, saying that, “When ingredients are intended to penetrate the skin for treatment of one kind or another, they should generally fit within the 500 Dalton rule.”

One quick note: Collagen has been shown to help with topical moisture retention, so don’t go tossing out your anti-aging skincare! Another hallmark of aging skin is moisture loss, so you do want all the help you can get in that regard.

What About Ingestible Collagen?

Collagen supplements come in pills, powders, “superfood” blends, drinks…you name it. The idea here is that if you eat or drink some extra collagen, it will make its way through your body and you’ll see healthier, younger-looking tissues.

Sounds good in theory. In practice, it’s not quite as useful as it sounds.

Collagen is a protein, and proteins are made up of much smaller building blocks called amino acids. It’s important to remember that, in terms of importance, our skin is basically the last on the list.

If there’s anything else in our body that needs amino acids or collagen (which there almost always is!), that’s where it will go first…or second…or thirtieth…or…well, you get the idea. This is the same reason that drinking more water doesn’t really translate to more hydrated skin.

“Collagen in the body is assembled from amino acids in our diet, so it is not possible for collagen in the diet to move directly into the skin. Rather, it requires the collagen to be broken down into amino acids and then reassembled into human collagen.” – Dr. Michael Edmonds

This isn’t to say that no collagen ever ingested eventually makes its way to your skin. Some of it might. There is also research that shows collagen supplements are definitively helpful for things like arthritis and joint pain, so again, collagen supplements aren’t useless by any means. They just aren’t working like you probably assumed they were.

Another Side of the Story

In the interests of presenting all sides of an argument, I am going to share one set of studies that seem to contradict what I’m saying here.

In those studies, one in Japan and one in France, two proprietary blends of fish and pig collagen peptides, Peptan F and P, respectively, were concluded to not only increase skin hydration but collagen density as well. I can’t fully endorse these findings, however, because the study was commissioned by the manufacturer of the product, Rousselot.

Is it possible that these two proprietary peptide supplements are truly doing what no other collagen supplement has been able to do? Sure. It’s also equally plausible that there’s a conflict of interest, so I personally am taking these findings with a grain of salt!


While these anti-aging regimens that boast collagen and peptides all sound great, they almost never work as advertised because:

  • Collagen molecules are too large to penetrate into our skin
  • Most supplements have to be broken down and reformed into usable collagen
  • Our skin is the last in line to receive a collagen boost (or any other nutrients)

To reiterate: I’m not saying collagen products are useless! If you already have a well-formulated collagen product, use it! Collagen has its merits. It just isn’t the miracle of anti-aging that it’s touted to be.

What do you think?

What are your experiences with collagen products? Do you take supplements or use collagen skincare? I’d love to hear about it in the comments below!

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