A new analysis by the Partnership for Safe Medicines (PSM) has raised concerns about the safety and legitimacy of peptides being imported and sold outside regulated medical channels.
The report reviewed hundreds of peptide-related shipments entering the United States in May and June 2026 and found a significant share linked to unverified or illegitimate manufacturing sources.
It also warned that rising demand for weight-loss and metabolic peptides is outpacing regulatory control, increasing the risk of unsafe or counterfeit products reaching consumers.
What the investigation looked at
The PSM analysis examined:
- 167 peptide shipments
- 1,792 related shipments involving antidiabetics such as semaglutide and tirzepatide
- FDA import records and customs data
- Manufacturer details and shipment descriptions
Researchers flagged shipments that appeared inconsistent with legitimate pharmaceutical manufacturing standards.
Main results
According to the report:
- 23% of peptide shipments came from facilities identified as illegitimate manufacturers
- Only 4% of peptide shipments were refused entry
- 12% of antidiabetic-related shipments were linked to illegitimate facilities
- Only 1.5% of those shipments were refused
The report also identified multiple shipments linked to so-called investigational peptides, including compounds not approved for general medical use.
Some shipments were labelled with vague descriptions such as “custom peptides,” making it difficult to confirm their contents or purpose.
Retatrutide shipments flagged
The report highlighted retatrutide, a weight-loss drug still in clinical trials and not approved by the US Food and Drug Administration (FDA).
Researchers identified eight shipments labelled as retatrutide entering the import system, including one shipment declaring more than 220,000 units.
The report stated that there is no legal commercial supply of retatrutide outside clinical trials, meaning any product sold online is considered part of the black market.
Safety concerns
PSM warned that many peptide products sold online:
- Are not clinically tested
- May come from unverified manufacturers
- Could contain incorrect doses or unknown substances
- May lack sterility or proper quality control
The report also said injectable products are especially risky due to possible contamination, incorrect concentration, or manufacturing defects.
Medical and regulatory experts cited in the report stressed that patients using these products lose the safety protections that come with approved medicines.
Regulatory challenges
The report noted that enforcement is difficult because suppliers often:
- Change product names or descriptions
- Mislabel shipments
- Use vague terms like “custom peptides”
- Shift to new compounds to avoid scrutiny
PSM said stronger import checks are needed, including tighter screening of unverified facilities and better inspection of unclear shipments.
Broader concern
The analysis concluded that the peptide market is expanding faster than regulatory systems can control.
It warned that growing public demand for weight-loss and wellness injections is creating space for unsafe and unregulated products to enter the supply chain.
PSM said regulators must strengthen oversight to ensure that only verified, clinically tested medicines reach patients through legal channels.