Key takeaways
- A TRM Labs analysis published October 6 found that about 75% of Chinese chemical vendors it tracked list both peptides and fentanyl precursors on their sites 1.
- Crypto payments to vendors selling both rose from $28.2 million in 2023 to $37.3 million in 2025, and about 57% of the identifiable money came from the US 1.
- One vendor charged by the Justice Department in 2023 was still listing semaglutide and Melanotan II as of September 12.
- The FDA says "research use only" labels don't make these products legal, and it sent warning letters to five peptide websites in August 23.
A blockchain analytics firm has put numbers on something people in the peptide world have whispered about for a while. Many of the overseas shops selling cheap "research" peptides are the same shops selling chemicals used to make fentanyl 1.
That matters for two reasons. It's one more sign that nobody is checking what's in these vials. And it means some of the money spent on gray-market peptides may end up with suppliers tied to the opioid trade, though the report can't show how much 1.
What the TRM Labs report found
TRM Labs identified more than 150 Chinese chemical manufacturers that accept cryptocurrency as of the third quarter of 2026, though not all are active 1. It checked their websites for peptides and fentanyl precursors, then traced the crypto payments they received.
About 75% of these vendors list both product types, and TRM calls that a lower bound because sellers often hide precursor listings after sanctions or indictments 1. Payments to vendors selling both grew from $28.2 million in 2023 to $33.8 million in 2024 and $37.3 million in 2025, roughly 32% over two years 1. Most payments moved from Bitcoin to the Tether stablecoin on the TRON network.
Where TRM could tie payments to a country, the US accounted for about 57% of the value sent to these mixed vendors, followed by Australia at about 25% and Thailand at about 10% 1.
The limits of the data
The report has real gaps, and TRM says so. It can't tell what share of a vendor's income came from peptides versus precursors, so it doesn't show that any individual peptide buyer funded trafficking 12. Most payments also pass through global exchanges that can't be tied to one country, so the US figures cover only the slice TRM could identify.
TRM also sells compliance software, and its blog post points readers to those products 1. The numbers line up with earlier work, though. In July, Axios reported Chainalysis data showing $27 million in crypto payments to gray-market peptide vendors in the first quarter of 2026 alone, up nearly 150% from the quarter before 4.
Melanotan II: a tanning peptide with a long warning history
Melanotan II is one of two peptides TRM named on the storefront of Anhui Rencheng Technology, a company the Justice Department charged in a June 2023 fentanyl precursor case 12. It's a synthetic version of a skin-darkening hormone that also affects appetite and sexual arousal.
It has never been approved anywhere. The FDA warned a US seller in 2007, the UK's MHRA warned the public in 2008, and Australia's TGA has fined suppliers. Case reports link it to new or changing moles and melanoma. Its nomination to the FDA's compounding category list was withdrawn in April 2026, and an advisory committee is due to review it by February 2027.
Semaglutide: an approved drug sold as an unapproved one
The other peptide on that storefront was semaglutide, the active ingredient in Ozempic and Wegovy 1. The brand-name drug has a deep evidence base, including a large heart-outcomes trial. A vial from an unknown overseas seller is a different thing: the FDA treats GLP-1s sold "for research purposes" as unapproved drugs 2.
Approved versions have also gotten cheaper on cash-pay sites. Medical Daily reported prices starting at $149 a month for the lowest-dose Wegovy pill and $199 for the Wegovy pen, both requiring a prescription 2.
"Research use only" isn't a shield
On August 24, the FDA sent warning letters to five websites selling peptides labeled "for research use only" 23. One letter, to Peptide Partners LLC, listed semaglutide, tirzepatide, retatrutide, tesamorelin, PT-141 and others as unapproved new drugs 3.
The FDA said evidence from the seller's own website showed the products were "intended to be drugs for human use," whatever the label said 3. It also flagged the bacteriostatic water sold alongside them as proof the vials were meant for injection.
The policy debate keeps moving
The supply-chain findings land in the middle of a fight over access. In an October 6 opinion piece, the Independent Institute's Raymond March argued that compounding pharmacies proved during the GLP-1 shortage that they can expand access, while saying peptides with no rigorous human trials deserve more caution 5. Pharmacy access, if it grows, would at least move some buyers away from anonymous crypto storefronts.
Comparison: the two peptides named in the report
| What it is | FDA status | Evidence (1–5) | Half-life | Banned in sport | |
|---|---|---|---|---|---|
| Melanotan II | Synthetic melanocortin (α-MSH) analog | Not approved | 3 | About 1 hour or less | Yes, at all times (S0) |
| Semaglutide | GLP-1 receptor agonist | Approved (Ozempic, Wegovy) | 5 | About 7 days | No; Monitoring Program |
The bottom line
The TRM report doesn't prove that any single peptide order paid for fentanyl chemicals. It does show that a large share of the overseas vendors selling cheap peptides also sell precursors, and that US buyers send most of the traceable money. Add the FDA's view that "research use only" labels don't make these products legal, and the gray market looks riskier than its prices suggest.
This is educational information, not medical advice.
Sources
- Americans Are Buying Peptides From the Same Chinese Chemical Vendors Selling Fentanyl Precursors: Sales Up 32% Since 2023 — TRM Labs, October 6, 2026. https://www.trmlabs.com/resources/blog/americans-are-buying-peptides-from-the-same-chinese-chemical-vendors-selling-fentanyl-precursors-sales-up-32-since-2023
- Americans paying for cheap online semaglutide may be sending money to vendors that also list fentanyl precursors — Medical Daily, October 8, 2026. https://medicaldaily.com/cheap-semaglutide-research-peptides-fentanyl-precursor-vendors-479725
- Warning letter: Peptide Partners LLC (MARCS-CMS 735063) — U.S. Food and Drug Administration, August 24, 2026. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/peptide-partners-llc-735063-08242026
- Chinese fentanyl makers find new U.S. market in peptides — Axios, July 7, 2026. https://www.axios.com/2026/07/07/chinese-fentanyl-makers-pivot-peptides
- Copycat pharmacies and the peptide market — Independent Institute, October 6, 2026. https://independent.org/article/2026/10/06/copycat-pharmacies-peptide-compounding