Weight loss medicines explained
Compounded, Counterfeit and Research GLP-1s: How to Tell What You Are Being Sold
Not every product sold as semaglutide or tirzepatide is the approved medicine. Some are compounded by pharmacies, some are falsified copies and some are chemicals sold for research. Knowing the difference protects your health.
Sources last reviewed by an editor on 2026-11-11.
This is general information about medicines regulation and patient safety, not medical or legal advice. Only a licensed prescriber who knows your health can decide whether a medicine or treatment suits you. Rules and product availability change, so confirm the current position with the official sources linked on this page. MedSpa Listings does not sell, prescribe or supply medicines.
Brand-name, compounded, falsified and research products
A brand-name medicine has been reviewed and authorised by a medicines regulator, and each batch is made to an approved standard.
A compounded medicine is prepared by a pharmacy for an individual patient. Compounding is legal in some countries under strict conditions, but the product has not been through the same approval as the brand-name version. Rules on compounding GLP-1 medicines have changed in several countries, including the United States and Australia.
A falsified medicine is a fake that pretends to be the real product. The World Health Organization has issued alerts about falsified semaglutide pens.
Research peptides are chemicals sold online with labels such as not for human use. They are not medicines, and regulators have warned against injecting them.
Why it matters
Products made outside an approved process can contain the wrong amount of the active ingredient, a different ingredient, or contaminants. Mistakes in measuring doses from vials have also led to people taking far more than intended.
Fake pens can look almost identical to the real thing, so price and convenience are not reliable signs of authenticity.
How to check a product
Get it from a licensed pharmacy with a prescription. Ask whether it is a brand-name product or a compounded preparation, and if compounded, which pharmacy made it and why.
Check the packaging, batch number and expiry, and look the product up on your national regulator’s register. The country guides below link to each regulator.
Report anything suspicious to the regulator and the pharmacy, and stop using a product that looks or behaves differently from what you were told.
Warning signs when buying online or at a clinic
No consultation, or a consultation that is only a short form nobody reviews. A legitimate prescriber asks about your health, your other medicines and your history before deciding.
Offers through social media messages, chat apps or marketplaces, payment by gift card or cryptocurrency, or pressure to buy several months at once.
Vials or pens with labels in a language or format that does not match your country, missing batch numbers, or products described as for research, laboratory or cosmetic use only.
A clinic that cannot tell you which pharmacy supplied the product, or that mixes the medicine with vitamins or other ingredients without explaining why.
Questions to ask before you start
Is this a brand-name medicine authorised in my country, or a compounded preparation? If compounded, which licensed pharmacy made it, and what is it made from?
Who is the prescriber, what is their registration and how do I contact them if I have side effects?
How will the dose be measured and increased, and what should I do if I miss a dose?
Frequently asked questions
Is compounded semaglutide legal?
It depends on the country and on current rules. In the United States, the end of the national shortages sharply narrowed when compounded copies can be made. Australia has banned compounding of replica GLP-1 medicines. Check the regulator in your country.
How can I tell if my Ozempic pen is fake?
Buy only from a licensed pharmacy, compare the packaging with the manufacturer’s description, check the batch number and report anything unusual to the pharmacy and your medicines regulator.
Are research peptides the same as semaglutide?
No. Products labelled for research use are not approved medicines, give no assurance about what they contain and are not meant to be injected by people.
Official sources
Rules and product lists change. These official pages hold the current position.
- World Health Organization: Medical Product Alert on falsified Ozempic (semaglutide)
- World Health Organization: warning on falsified medicines used for diabetes treatment and weight loss
- U.S. FDA: policies for compounders as national GLP-1 supply stabilizes
- U.S. FDA: concerns with unapproved GLP-1 drugs used for weight loss
- Australian Government Department of Health: protecting Australians from unsafe compounding of replica weight loss products
Treatment guides
Rules country by country
Who regulates GLP-1 medicines, Botox and fillers, who can prescribe, and how to check a clinic, for each country.