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What are peptides? A plain-English guide to peptide therapy
Published · Editorial team
Medical review pending · Last updated
Peptides are short chains of amino acids, the same building blocks that make up proteins. Your body makes thousands of them, including hormones like insulin and GLP-1.
Peptide medicines you may already know
Many mainstream drugs are peptides: insulin, semaglutide, tirzepatide, and oxytocin. Others, like tesamorelin (Egrifta®) and bremelanotide (Vyleesi®), are FDA-approved for specific conditions.
Approved vs. compounded vs. "research use only"
- FDA-approved peptides have been reviewed by FDA for safety, effectiveness, and manufacturing quality for the labeled use.
- Compounded peptides are made by a licensed pharmacy for a specific patient's prescription. They are not FDA-approved, and federal law limits which ingredients may be used.
- "Research use only" peptides sold online are not made or intended for people. Avoid them.
What changed in 2026
In April 2026, FDA removed 12 peptides from its "Category 2" list of substances with significant safety concerns after their nominations were withdrawn. In July 2026, FDA's Pharmacy Compounding Advisory Committee recommended six of them (BPC-157, TB-500, KPV, MOTS-c, Epitalon, and Semax) for the 503A Bulk Drugs List. On October 28, 2026, HHS announced an interim policy, published in the Federal Register on October 30, 2026, allowing licensed pharmacies to compound those six under strict conditions while formal rulemaking proceeds. For the details, read are peptides legal in 2026? Others, such as CJC-1295 and ipamorelin, remain outside lawful compounding channels. See our peptide hub for the current list.
The evidence question
Regulatory access is not the same as proven benefit. For many popular peptides, high-quality human trials are limited. A licensed provider can help you weigh what is known, what is not, and safer alternatives.
Sources
- FDA: Bulk drug substances nominated for use in compounding under section 503A (Categories 1-3, PDF)
- Federal Register 2026-07361: PCAC notice of meeting on bulk drug substances nominated for the 503A list (Apr 16, 2026)
- FDA: Pharmacy Compounding Advisory Committee meeting, July 23-24, 2026
- Federal Register: HHS Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances (91 FR 68526, published Oct 30, 2026)
- FDA: Compounding and the FDA, questions and answers
Sources are listed for reference and do not imply endorsement. Regulatory status can change; check the date above.
This article is for education only and is not medical or legal advice. A licensed clinician decides whether any treatment is appropriate for you.