Grey market and research peptides: what you are actually buying

This is a different category from compounded medicine, and the difference matters more than the similar vocabulary suggests.

A compounded GLP-1 comes from a licensed pharmacy, against a prescription, from a prescriber who can be identified. Grey market product typically comes from a website selling vials labelled for research use, with no prescription, no pharmacy, and nobody accountable to a licensing board.

The price is lower again. What you give up is every remaining check.

What the label is telling you

Products sold this way frequently carry a phrase along the lines of not for human consumption or for research use only.

That is not a technicality or a legal fig leaf that everyone winks at. It is the seller stating that the product was not made to be injected into a person, and it is the reason they can sell it without a prescription. If a product is labelled that way and someone tells you to inject it anyway, the label and the advice cannot both be right.

What testing has found

Researchers have bought these products and tested them.

A study published in JAMA Network Open in 2024 assessed semaglutide bought online without a prescription and found safety and quality problems in the sample, including issues with what the products actually contained.

A separate 2024 study in the Journal of Medical Internet Research surveyed online sellers offering semaglutide without a prescription, then bought and analysed product. It found problems across the market, not confined to one bad seller.

A 2025 paper tracked the international supply of illicit semaglutide and weight loss medicines sold online, describing a supply chain that runs largely outside any regulatory system.

The common finding across all three is not that every vial is fake. It is that you cannot tell from the outside, and the usual reassurances are absent by design.

What the FDA has said

The agency has publicly flagged several problems that apply directly here.

Fraudulent product with false information on the label.

Counterfeit drugs, which the FDA describes as products claiming to be authentic that may contain the wrong ingredients, too little or too much active ingredient, or no active ingredient at all.

Raw ingredient quality, addressed with an import alert to stop GLP-1 active ingredients with potential quality problems entering the country.

Salt forms, semaglutide sodium and semaglutide acetate, which the FDA says are different active ingredients from the ones in approved drugs.

Two molecules that cannot be compounded at all. Retatrutide and cagrilintide have never been FDA approved. They circulate widely in this market precisely because there is no legitimate channel for them.

The dosing problem underneath all of it

Even if a vial contains exactly what it claims, you are measuring your own dose from powder or solution with a syringe, usually with instructions from a forum.

The FDA has received adverse event reports, some involving hospitalisation, connected to dosing errors with compounded injectable semaglutide, where at least a pharmacy prepared the vial. The same risk applies here without the pharmacy.

Why people do it anyway

Usually price, and sometimes access. Both are real, and it is not our place to lecture anyone about a system that priced them out.

What we would say is that the price gap is smaller than it was. In 2026 the approved products became available at substantially reduced cash prices through a federal channel, and eligible Medicare beneficiaries can get certain GLP-1 drugs for fifty dollars a month under a CMS demonstration running to the end of 2027. Neither is universal, and neither helps everyone. But if cost is the reason, those two routes are worth checking before the grey market one.

What to ask yourself

• Does the label say the product is not for human consumption?
• Is there a prescriber, and is that prescriber licensed in my state?
• Is there a pharmacy in this chain at all?
• If something goes wrong, who is accountable and to whom?
• Have I checked the federal cash price and my Medicare eligibility?

Sources

• Safety and Risk Assessment of No-Prescription Online Semaglutide Purchases. JAMA Network Open, 2024. doi:10.1001/jamanetworkopen.2024.28280
• Multifactor Quality and Safety Analysis of Semaglutide Products Sold by Online Sellers Without a Prescription. Journal of Medical Internet Research, 2024. doi:10.2196/65440
• Made in China: The international supply of illicit semaglutide and weight loss medicines online. Emerging Trends in Drugs, Addictions and Health, 2025. doi:10.1016/j.etdah.2024.100169
• FDA, "FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss"
• Centers for Medicare and Medicaid Services, Medicare GLP-1 Bridge

How we verify: see /how-we-verify.

Keep reading

How to check whether a provider is legitimate, at /guides/how-to-check-a-telehealth-provider.

What the FDA has documented about compounded semaglutide, at /guides/is-compounded-semaglutide-safe.