What are GLP-1 medications?

GLP-1 medications are the reason most people have heard the word "peptide" at all. Semaglutide, tirzepatide and the drugs built around them have reshaped weight management and diabetes care. Unlike most of what this book covers, these are licensed, approved medicines with substantial trial data — which makes the counterfeit market that has grown up around them all the more important to understand.

What they actually are

GLP-1 stands for glucagon-like peptide-1 — a hormone the body produces naturally that helps regulate blood sugar and appetite. GLP-1 receptor agonists are medicines that act on the same receptor. The best known are semaglutide (sold as Ozempic and Wegovy) and tirzepatide (sold as Mounjaro and Zepbound), the latter being a dual GLP-1/GIP agonist.

These are the opposite end of the spectrum from the research-peptide market. They are approved, regulated, prescribed and dispensed through licensed channels — and they have the clinical trial evidence to match.

The part the headlines skip: counterfeits

The success of these drugs created an enormous grey market — and this is where the honest picture matters most. The book examines the counterfeit GLP-1 problem in detail. One illustrative finding: an analysis of imported semaglutide found that roughly 60% of the Chinese manufacturers exporting the active ingredient to the United States were not permitted, under their own country's law, to distribute it for human use domestically.

The implication is uncomfortable. Compound sold to British, American and European buyers — often through telehealth platforms or messaging-app vendors operating beyond their regulators' reach — can be manufactured under standards the originating country itself does not consider adequate for human use. Adverse-event reporting systems have logged hundreds of reports relating to compounded GLP-1 products, including deaths.

The distinction that matters

This is the single most useful thing to take away: "GLP-1" can mean two completely different things. It can mean a licensed, prescribed medicine with years of trial data — or it can mean a compounded or counterfeit copy bought through an unregulated channel. The word is the same. The risk profile could not be more different.

The sober bottom line

GLP-1 medicines are a genuine pharmaceutical success story and the centre of a dangerous counterfeit market. Both things are true at once. Understanding which one you are actually looking at — licensed medicine or unregulated copy — is exactly the kind of clarity the book is built to provide.