What is really in the vial? What the labs found

Why the question matters

When a peptide is bought outside the regulated pharmaceutical chain, the buyer relies on the label or a certificate of analysis on a website. Several official and academic labs have put that to the test, and falsification of biotechnology drugs, peptides included, is now documented in developed countries too¹⁶. Their results help explain why regulators in the region issue alerts⁶⁷.

Semaglutide from the internet

A 2024 study tracked semaglutide sold without a prescription: of 317 pharmacy links, 134 (42.3%) led to 59 illegal sites. The researchers placed 6 orders: only 3 vials arrived and the pens were never delivered¹. In the lab, purity was 7.7% to 14.4% vs the 99% claimed, content was 28.6–38.7% above label, and endotoxin was present in every sample, although no viable microorganisms were found¹. In the Netherlands, two people without diabetes arrived in a coma with severe hypoglycemia after injecting "semaglutide" bought without a prescription: the cause was synthetic insulin¹¹. The WHO, for its part, issued a 2024 alert on falsified Ozempic detected in Brazil, the United Kingdom and the United States, with risks of incorrect dosing, contamination, or unknown or substituted ingredients¹².

Metals and bacteria

Belgium's Scientific Institute of Public Health analyzed the ten most frequently encountered falsified peptides on its market, bought from three suspected illegal internet pharmacies. Amount per unit varied widely; the cysteine-containing peptides had purity of 5% to 75%; several samples contained arsenic (all in inorganic form) up to 10 times the ICH limit for parenteral products, and one was contaminated with lead². For reference, the ICH Q3D guideline sets a permitted daily exposure for parenteral products of 15 µg for arsenic and 5 µg for lead¹³. The same group documented haemolytic Bacillus cereus in two illegal injectable peptides³.

Growth hormone and undeclared analogues

A study of somatropin (growth hormone) sold online found that 94% of 17 vendors required no prescription and that every sample contained less somatropin than labeled⁴. In another case, a seized vial contained a new peptide, a GHRP-2 analogue not previously described⁵.

What we do not know

Despite their popularity, we found no independent PubMed-indexed purity or contamination analysis of BPC-157 or TB-500 vials sold to the public (search of October 9, 2026); an anti-doping lab only identified BPC-157 in confiscated vials and developed its detection in urine¹⁰. The alerts from INVIMA and Guatemala's Health Ministry start precisely from that lack of quality evaluation⁶⁷.

The debate

Sellers often offer per-lot certificates of analysis. Regulators answer that these products "have not been evaluated in terms of quality, safety or efficacy" and that every person has the right to know what is being sold to them⁶⁷. The FDA also notes that the semaglutide salts (sodium or acetate) found in some products are different active ingredients from the approved one⁸.