Collagen benefits? Why collagen alone doesn’t help

Before asking whether collagen works, it’s worth looking at its role. Collagen is the most important structural protein in your skin. Young skin consists of around 80 percent type I collagen and about 15 percent type III collagen in the dermis (Reilly and Lozano, 2021). The fibers support the skin and give it firmness, much like a framework. Without replenishment, the framework gradually loosens.

The collagen content of the skin increases until around the mid-20s. After that, the body produces a little less each year. According to the review, the decline is around 1.0 to 1.5 percent per year. Sun exposure and smoking accelerate the breakdown (Reilly and Lozano, 2021). So the question of where collagen might have an effect from the outside or inside starts with a natural process.

So it seems natural to consider supplementing with collagen. But whether collagen works when you eat or drink it depends on what else is happening in your body and your skincare routine. Our hub on skin aging explains how skin aging works overall.

A meta-analysis from 2023 evaluated 26 studies with 1,721 participants. On average, collagen hydrolysate improved skin hydration and elasticity, especially when taken for more than eight weeks (Pu and colleagues, 2023). Many see this as evidence that collagen works. Fish collagen performed best.

The authors of the more recent paper see no clinical evidence yet that collagen supplements alone can stop skin aging (Myung and Park, 2025). That doesn’t mean collagen is unimportant to us. It means the question of whether collagen works depends on how different factors interact. Collagen is a building block, and a building block needs the right conditions for collagen to have an effect on the skin.

No serious side effects were reported in the studies (Pu and colleagues, 2023). Mild gastrointestinal symptoms are possible (DAK, 2026). The source is more important. Collagen in powders and capsules comes from cattle, pigs, or fish. Anyone with an allergy to fish or animal protein should be cautious and consult a doctor first (Verbraucherzentrale, 2025).

Besides whether collagen has an effect, the rest of the formula matters too. Check the other ingredients. Many products contain additives such as nicotinamide or piperine. Nicotinamide can cause redness, and piperine is not recommended during pregnancy (Verbraucherzentrale, 2025). So before considering whether collagen has an effect, it’s worth checking the ingredients list. If you’re pregnant or breastfeeding, or have a pre-existing condition, talk to your doctor first. The same applies if you take medication regularly.

Collagen is found in animal foods that are high in connective tissue, such as gelatin, bone broth, or fish skin. During digestion, however, the body breaks it down into amino acids. It doesn’t specifically use them to build new collagen for the skin (DAK, 2026).

Your body needs enough protein to produce its own collagen, especially the amino acids glycine and proline. It also needs vitamin C. Vitamin C contributes to normal collagen formation for the normal function of the skin (Regulation EU 432/2012). Bell peppers, citrus fruits, berries, and green vegetables are rich sources.

You can find out how to get enough protein in our article on getting the right amount of protein. This foundation is the basis for everything else. Whether additional collagen has an effect also depends on how well your diet already provides you with protein and vitamin C.

Many people also ask whether collagen has an effect when applied to the skin. Collagen in creams and masks is a large molecule. Substances over about 500 daltons hardly penetrate the outer layer of the skin (Bos and Meinardi, 2000). Collagen is many times larger, so it stays mainly on the surface.

There, it binds moisture and makes the skin more supple. This makes collagen a good skincare partner. Collagen’s effect on the surface complements active ingredients that work deeper down. That’s why we never use collagen in skincare on its own, but combine it with renewal and energy.

This is the key. Collagen is a building block, but a building block can’t put itself in place. The skin needs to renew itself, and for that it needs signals and energy. Whether collagen can have an effect therefore depends on the whole system.

In skincare, retinal supports renewal. Read about how it works and its limitations in the article on retinal. NAD+ supports cellular energy; find out more in the article on the effects of NAD+. Only when building blocks, renewal, and energy come together does the picture become complete. Without renewal and energy, even good collagen can have little effect.

The basics come first. Sun protection, not smoking, and getting enough sleep are among the most effective ways to prevent premature skin aging (Verbraucherzentrale, 2025). If you want collagen to have an effect, lay the foundation there and build your routine on it.

On its own, collagen does little for your skin according to current knowledge, but as part of the bigger picture, it’s an important building block. Research is still investigating whether collagen has an effect when you take it. When applied to the skin, collagen mainly affects the surface, where it complements other active ingredients. Serious side effects are rare, but you should know where it comes from.

This is how you should do it, and we’re convinced of it. If you want collagen to have an effect in the body, start by creating the right conditions with enough protein, plenty of vitamin C, sun protection, and sleep. Build on that, for example with our SIX ELEMENTS SKIN COLLAGEN CAPSULES as part of your routine and skincare with retinal and NAD+. Our new Glow Mask brings these three together: collagen, retinal, and NAD+. For collagen to have an effect as part of the bigger picture, never think of it on its own, but holistically.