Summary
-
What is collagen?
Collagen is a type of protein found in the skin (types I and III collagen), joints (type II collagen) and other parts of the body. It uniquely contains the amino acid hydroxyproline, along with other amino acids. Collagen in supplements is typically hydrolyzed, i.e., broken down to amino acids and/or chains of amino acids (peptides) to improve absorption as well as the ease with which it mixes into liquids, such as cold water. The specific composition of these "collagen hydrolysate" or "collagen peptide" products can vary somewhat depending on how they are hydrolyzed (which typically involves heat and enzymes). Gelatin also contains collagen, but is not soluble in cold water (see What It Is). -
Health benefits of collagen:
Collagen appears to modestly reduce wrinkles and slightly improve the appearance of cellulite. It may also modestly improve joint pain and/or flexibility in osteoarthritis, help with tendons, and possibly help with the treatment of pressure ulcers, burns, and bleeding gums. These effects can require two to six months of daily use (see What It Does). -
What did CL's tests of collagen supplements find?
ConsumerLab's tests showed that products contained their expected amounts of collagen, ranging, per daily serving, from about 2.9 grams to 20 grams among powders, and from 1.8 grams to 6 grams for tablets and capsules. A cartilage-based product contained a much smaller amount (10 mg) but this is appropriate for that particular ingredient (see What CL Found). 
Best collagen supplements?
Among the products Approved in testing, ConsumerLab selected a Top Pick for skin (wrinkles) and a Top Pick for joint pain. In addition to passing tests for quality, these products contained brands used in clinical studies that suggest benefits and, for powders, had superior taste when mixed in liquid.-
How much collagen should I use?
Typical daily dosage of hydrolyzed collagen is 1 to 10 grams. Dosing with UC-II, a cartilage-based product, is much lower. Collagen may be taken with or without food. There is no "vegan collagen," as plants do not produce collagen. However, there are some supplements that contain certain vitamins, amino acids, and other ingredients used in building collagen. For details see ConsumerTips. -
Collagen supplements safety and side effects:
Collagen supplements are generally well-tolerated, but mild side effects including gastrointestinal symptoms, headache, dizziness and rash can occur. People with allergies to specific sources of collagen (such as fish) should avoid collagen products derived from these sources. Stop taking collagen before certain bone-related blood tests. For details, see Concerns and Cautions.
