Beginner's guide

Peptides 101

Welcome! If peptide videos have left you more confused than when you started, you're in the right place. Here's everything you need, in about five minutes.

What is a peptide?

A peptide is a short chain of amino acids, the same building blocks that make up proteins. Long chains are called proteins and short ones are called peptides. Your body makes thousands of them, and many act as messengers. Insulin, for example, is a peptide hormone that helps control blood sugar.

"Peptides" is a huge, loose category. It covers prescription medicines, ingredients in skin creams, food supplements like collagen, and experimental compounds that have never been properly tested in people. The word alone tells you nothing about whether something is safe or works.

Approved medicines vs. "research-only" compounds

• Approved drugs (for example semaglutide and tirzepatide) have passed large clinical trials. Regulators like the U.S. FDA reviewed the data, and they're made under strict quality controls. They're prescribed by clinicians.
• Dietary supplements (for example collagen peptides) are sold as foods. In the U.S. the FDA does not approve supplements before they are marketed.
• Research purposes only compounds (for example BPC-157 and TB-500) aren't FDA-approved medicines. Product quality can vary, and the human evidence is usually early and limited. Some, including BPC-157 and TB-500, are banned in sport by the WADA Prohibited List.

How to read a study (the quick version)

1. Who was studied? Cells in a dish → animals → people. Lab and animal results often don't hold up in humans.
2. How many? 12 people is a pilot. Thousands is much more convincing.
3. Was there a comparison group? A randomized controlled trial (RCT) compares people who got the treatment with people who got a placebo. Without one, it's hard to know whether the treatment did anything.
4. What was measured? A lab marker isn't the same as feeling better or living longer.
5. Who paid? Industry funding is common and not automatically bad, but it's worth noting.
6. One study is never the final word. Look for systematic reviews and meta-analyses that pool many studies.

New to the terms? See the glossary.

How to pick a quality source

• Third-party lab tests. Look for a recent certificate of analysis (COA) from an independent lab, matched to your batch.
• Citations you can click. The best sources link to the actual study or FDA label.
• Clear labeling. Purity, amount per vial, and batch number should be easy to find.
• Know the study type. Human trials, animal studies and lab work each tell you something different.
• Transparent sellers. Real contact details, clear policies, and honest disclosure of affiliate links.
• For prescription drugs, go through a licensed prescriber and pharmacy.

Where to go next

Read our plain-English guides to popular peptides, or browse the newsletter archive.

Not medical advice. Education only. We don't sell anything or tell you what to take. Label doses are there so you can follow along with your prescriber. Talk to a licensed clinician about your health.