Peptides, chains of amino acids that are the building blocks for protein, not only help boost athletic performance, but can also treat aging, obesity, cancer, and diabetes. Naturally found in the body, and also in food and supplements, there are many different peptides, and each has a specific function in the body, say experts.

According to USA Today, because creatine peptides help release hormones that affect athletic performance, muscle recovery and body composition, they are a favorite of elite athletes. Other peptides affect the endocrine system, which plays a unique role in organ development and growth. Copper peptides act as antioxidants which the National Cancer Institute says counteract harmful free radicals from toxic environmental factors such as cigarette smoke, UV rays and pollution. Collagen peptides repair skin cells and can help reduce and prevent fine lines and wrinkles, as well as promote the growth of healthy nails and hair.

Collagen peptides help make collagen and elastin, the proteins found in healthy skin, so they are an important anti-aging tool, says WebMD. Antimicrobial peptides can help your body fight bacteria and promote wound healing. Creatine and collagen peptides help boost muscle growth and repair. Scientists are also looking at whether some peptides can help with weight loss, but more studies are required on this topic.

While the body manufactures peptides on its own, many foods and supplements are excellent sources, says Dr. Mary Stevenson, a professor of dermatology at NYU Langone Health. “All the food we eat is broken down by the body into amino acids,” she says. Animal products like meat, milk, and eggs are the best source of peptides says Josh Redd, a chiropractic physician and founder of RedRiver Health and Fitness. Beyond animal sources, you can find peptides in plant-based foods such as legumes, flaxseeds, hemp seeds, soybeans, oats, and wheat.

You can find many powder and capsule supplements, including collagen supplements, that have active peptides, says USA Today. And they can be found in topical beauty products such as creams, lotions, face masks and serums.

Peptides have also been used to create drugs to treat a variety of diseases, says WebMD. More than 100 peptide drugs are available in the U.S. to treat conditions like Type 2 diabetes, multiple sclerosis, and high blood pressure. Unlike cosmetics and supplements, these drugs have been thoroughly researched and are tightly regulated by the Food and Drug Administration.  However, always ask your doctor if you have any questions about taking an over-the-counter or prescription peptide drug.