What Are Peptides?

Peptides are strings of molecules called amino acids, which are the "building blocks" of proteins. Peptides are basically short proteins that are about 2-100 amino acids long.

Peptide supplements may have anti-aging, muscle growth, and fat loss benefits. (Photo Credit: Moment/Getty Images)

Your body makes peptides that serve important functions in some of your body's most necessary processes. For instance, insulin is a 51-amino-acid-long peptide hormone that helps your cells take in sugars from your food to use for metabolism and store them in your liver.

Researchers have been working to develop peptides as treatments for some medical conditions since 1921. In fact, insulin was the first peptide ever made in a lab by scientists (called a synthetic peptide), and it's been used to treat people with type 1 diabetes since 1923.

Peptide drugs may have some advantages over other drugs because they may:

Be easier to send where they need to go in your body

Have fewer side effects

Be safer because when your body breaks them down, their byproducts are amino acids that your body can recycle

Studies show that some peptides may also have benefits for your skin, muscles, and maybe your weight. So, for decades, companies have been putting them into skin care products and dietary supplements you can buy over the counter.

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Peptides vs. Proteins

Both peptides and proteins are made up of strings of amino acids that are held together by peptide bonds. The main difference is that peptides are shorter strings of amino acids than proteins, although the terms aren't used precisely. Most scientists refer to chains with over 100 amino acids as proteins.

Also, scientists call peptides that are about