Collagen is a family of proteins found widely in all mammals, with types I, II, and III being the most common in the human body. As far as its role in the body, it helps make up the structure of our skin, bone, cartilage, muscle, and more, with the purpose of helping tissues be elastic and withstand stretching (so, for example, it keeps skin looking young and supple).* We actually make our own internal supply of collagen, via our cells' fibroblasts (assuming they have the amino acids and other required nutritional building blocks they need). In fact, it's made by our body throughout our lifetime; however, it also decreases with age, and your natural endogenous levels can also be reduced by environmental factors and stressors, such as sun damage and high-sugar diets.
This is where collagen supplements come in: Collagen supplements are broken-down digestible forms of collagen (derived from things like cows, fish, and chickens), usually in a powdered form.* When ingested, your cells' fibroblasts can use the amino acids to stimulate and enhance your own natural collagen production.* (If you are interested in trying a supplement, we rounded up our all-time favorites—check it out for our recommendations.)
All sounds great, yes? Well, you might be wondering if there is anything negative you need to keep an eye out for when trying a new supplement. Here, we explain the most common complaints.