Peptide questions, answered briefly
Short answers to the questions readers ask most. Each answer links to the full guide, where the sources are listed.
What are peptides?
Peptides are short chains of amino acids joined by peptide bonds, usually from 2 to about 50 units long. Longer chains are called proteins. The body uses peptides as hormones and signals; insulin and oxytocin are natural examples. Read more in what peptides are.
Are peptides steroids?
No. A peptide is a chain of amino acids, while a steroid is a fat-soluble molecule built on four fused carbon rings, usually made from cholesterol. The law treats them differently too: in the United States anabolic steroids are Schedule III controlled substances, while most research peptides are not scheduled. See are peptides safer than steroids.
Is BPC-157 an approved medicine?
No. BPC-157 is not approved by the US FDA or other major regulators. Most of its research comes from animal studies by one group in Zagreb, and a 2026 review found only three small human reports. The World Anti-Doping Agency lists it as prohibited. Details are in the BPC-157 guide.
Is retatrutide approved?
Not as of October 2026. Retatrutide is an investigational Eli Lilly drug that acts on GIP, GLP-1 and glucagon receptors. It showed large weight loss in phase 3 trials, and Lilly has said it plans to submit it to the FDA by early 2027. Products sold online as retatrutide are not the trial medicine. See the retatrutide guide.
Do peptides need to be refrigerated?
Usually cold storage helps, but the form matters most. Manufacturer handling notes advise keeping dry powder in a freezer for long-term storage, with a refrigerator acceptable for short periods. Dissolved peptides break down much faster and are best used quickly. Approved pens follow their own label rules. Read the peptide storage guide.
How do I read a certificate of analysis?
Check that the report names a real, identifiable laboratory, matches the exact batch you have, and shows identity as well as purity. A purity figure alone says nothing about sterility or endotoxins. A certificate can also refer to another batch or be invented. The certificate of analysis guide walks through each part.
Last updated October 27, 2026.