Move over, protein bars. Hello, collagen bars? Collagen—which is sourced from the bones, cartilage, and skin of animals (including cows, chickens, and fish)—has been gaining popularity. This is in part thanks to the Paleo diet craze, which has sparked interest in “nose-to-tail” nutrition, or consuming more than just muscle meat from animals. Collagen is sold in powdered form, and also used in expensive protein bars, beauty gummies, and drinks. So is collagen the new must-eat superfood? Or is it a hyped-up trend not worth your hard-earned cash? Here’s what you need to know.

Collagen isn’t just found in animals. We produce it in our own bodies too. In fact, it’s the most abundant structural protein in the human body, and the main component of connective tissue. It’s found in our bones, tendons, ligaments, hair, skin, organs, muscles, and blood vessels.

Our bodies manufacture collagen from amino acids, which we consume in protein-rich foods. Research shows other nutrients are involved with collagen production too, including copper and vitamins A and C, along with plant pigments called anthocyanidins—which are found in deep red, purple, and blue produce (such as blueberries, blackberries, and raspberries).

As we age, we produce less collagen, which leads to wrinkles, sagging skin, and weakened joints. Certain lifestyle factors also interfere with collagen production, including consuming excess sugar and alcohol, sun exposure, and smoking.

Now, you may be wondering: If your body makes collagen itself, is there any benefit to eating the stuff?