What has been found in fake Ozempic and semaglutide?
Fake Ozempic and counterfeit semaglutide have contained insulin instead of semaglutide in one case confirmed by a laboratory (PMID 41125326). Two Dutch reports say synthetic insulin caused two more comas (PMID 42390457). One purchase study received three vials (PMID 39509151). Their purity was 7.70% to 14.37% (PMID 39509151). The labels claimed 99% purity (PMID 39509151). Their semaglutide content was 28.56% to 38.69% above label (PMID 39509151). Each claim was checked on 21 August 2026.
These findings describe separate products. They do not show what is inside any other pen or vial.
What do genuine GLP-1 medicines do?
Genuine drugs can produce large, measured weight-loss results. The trials below knew what each product was and how strong it was.
| Evidence | Population | Measured finding | Funding and source |
|---|---|---|---|
| Tirzepatide 5 mg, SURMOUNT-1 | 2,539 adults with obesity or overweight plus a related condition, without diabetes | Mean weight change at 72 weeks was -15.0% (95% CI -15.9 to -14.2). | Funded by Eli Lilly. PMID 35658024, NCT04184622. Checked 21 August 2026. |
| Tirzepatide 10 mg, SURMOUNT-1 | Same trial population | Mean weight change at 72 weeks was -19.5% (95% CI -20.4 to -18.5). | Funded by Eli Lilly. PMID 35658024, NCT04184622. Checked 21 August 2026. |
| Tirzepatide 15 mg, SURMOUNT-1 | Same trial population | Mean weight change at 72 weeks was -20.9% (95% CI -21.8 to -19.9). | Funded by Eli Lilly. PMID 35658024, NCT04184622. Checked 21 August 2026. |
| Placebo, SURMOUNT-1 | Same trial population | Mean weight change at 72 weeks was -3.1% (95% CI -4.3 to -1.9). | Funded by Eli Lilly. PMID 35658024, NCT04184622. Checked 21 August 2026. |
| Once-weekly semaglutide meta-analysis | Four randomised trials with 3,447 patients | Semaglutide produced clinically meaningful weight loss. It outperformed placebo on weight. It also outperformed placebo on waist circumference and body-mass index. The abstract gives no pooled effect estimate or confidence interval. | PubMed lists grant No. 2020KT1112 from the Guangdong provincial traditional-medicine research project. PMID 34981419. Checked 21 August 2026. |
SURMOUNT-1 recorded stomach and bowel events more often than any other adverse event (PMID 35658024). Most were mild or moderate. Adverse events led 4.3%, 7.1%, and 6.2% of the tirzepatide groups to stop treatment (PMID 35658024). The placebo figure was 2.6% (PMID 35658024). Eli Lilly funded the trial. These findings were checked on 21 August 2026.
The trial results do not show what is inside a different product. Laboratory tests answer that question.
What did researchers measure in vials bought online?
A research team placed six orders for semaglutide products. Three injection vials arrived. Three prefilled pens did not arrive. The papers call the missing orders nondelivery scams. These results come from one set of purchases reported in two papers.
| Delivered vial | Purity measured | Purity claimed | Semaglutide above label | Primary record |
|---|---|---|---|---|
| Vial 1 | 7.70% | 99% | +28.56% | PMID 39509151, PMCID PMC11582493. Checked 21 August 2026. |
| Vial 2 | 14.37% | 99% | +38.69% | PMID 39509151, PMCID PMC11582493. Checked 21 August 2026. |
| Vial 3 | 8.97% | 99% | +33.58% | PMID 39509151, PMCID PMC11582493. Checked 21 August 2026. |
JMIR reports endotoxin detected in all three vials (PMID 39509151). The full text gives less than 2.8658 EU/mg for one vial (PMID 39509151). It gives less than 2.1645 EU/mg for another vial (PMID 39509151). It measured 8.9511 EU/mg in the third vial (PMID 39509151). JAMA calls only the last result high and a sign of possible contamination (PMID 39093567). No live microbes were found in the three vials (PMID 39509151). The laboratory trace showed only semaglutide and no peptide-like impurity (PMID 39509151). All findings were checked in the full text on 21 August 2026.
Each result answers a different question. Purity tells how much of the measured powder was semaglutide. Content compares the amount found with the amount on the label. Endotoxin is a product of bacteria. A sterile result means no live microbes grew in that test. It does not erase an endotoxin result. These facts were checked in PMID 39509151 on 21 August 2026.
A visual check failed 59% to 63% of the pack checks (PMID 39509151). That visual finding was checked on 21 August 2026. It did not measure what was in each vial. The laboratory used LC-MS for the content results.
The Hungarian Scientific Research Fund supported the study through grant NKFI-ID 143684. The full papers are JMIR, PMCID PMC11582493 and JAMA Network Open, PMCID PMC11297364. Both were checked on 21 August 2026.
Three selected vials cannot give a rate for the whole market. The study also does not show that every fake product contains insulin.
Which clinical cases confirmed insulin or other outcomes?
| Source | What the source establishes | What remains uncertain |
|---|---|---|
Italy, PMID 41125326 | A 31-year-old woman entered hypoglycaemic coma after injecting a product sold as semaglutide. Toxicological analysis found insulin instead of semaglutide in the vial. | This is one laboratory-confirmed product. |
Netherlands, PMID 42390457 | Two people who injected products sold as semaglutide arrived in coma. Both had severe hypoglycaemia. Both had hypokalaemia. Both had hypothermia. The authors attributed both cases to synthetic-insulin intoxication. Continuous glucose infusion was needed for up to two days. | The abstract does not report a chemical analysis of either product. |
| Austria, BASG announcement | BASG received reports that several patients needed hospital treatment after suspected counterfeit Ozempic. The reported hypoglycaemia and seizure indicated insulin substitution to the regulator. | BASG described a clinical indication, not a laboratory confirmation. It published no patient count beyond “several.” |
Belgium, PMID 41773123 | An 18-year-old woman developed euglycaemic ketoacidosis after using online-purchased semaglutide. The paper records persistent nausea, vomiting, and reduced intake. The case report says no financial support was received for the submitted work. | The product was not analysed. Its contents remain unknown. The authors proposed starvation as the most likely mechanism. |
Each case source was checked on 21 August 2026. The cases answer different questions. Italy tested the vial. The Dutch abstract names the cause but gives no vial test. Austria describes a clinical sign. Belgium did not test the product. No case gives a rate for other products or users.
What do 234 European safety reports show?
A 2026 study found 234 EudraVigilance reports about suspected fake semaglutide from 1 January 2018 to 31 December 2025 (PMID 42137313). Vomiting, nausea, and low blood sugar were the most reported suspected reactions. The paper classed 209 of 234 reports, or 89.3%, as serious (PMID 42137313). It recorded female patients in 172 of 234 reports, or 73.5% (PMID 42137313). These results were checked on 21 August 2026.
All 234 reports were spontaneous reports (PMID 42137313). The paper does not know how many people were exposed. It cannot give an incidence or any other risk rate. It cannot show that the products caused each event. Some products were suspected rather than confirmed fakes. Other fake products may never have been noticed or reported.
The report set demonstrates what people sent to the database. It cannot say how often these events happen among all users.
The paper received support from PON 01_01227. The full EudraVigilance analysis, PMCID PMC13168152 was checked on 21 August 2026.
What does “falsified medicine” mean in the EU?
Article 1(33) of Directive 2001/83/EC says a medicine is falsified when claims about its identity, source, or supply history are false. Identity includes the pack, label, name, mix, and strength of ingredients. The same rule excludes quality faults made by mistake. The current text was checked on 21 August 2026.
That rule explains the word used on this page. This page does not apply the rule to a given product.
How can you spot fake Ozempic or semaglutide?
EMA and HMA list five signs for products sold as GLP-1 drugs in the EU. One sign is a false claim of official backing. Another is sale through an unofficial site or social media. A third is a claim that the product is better without research proof. A fourth is sale outside licensed pharmacies or care providers. The last is an absent EU common logo or national register entry for the site.
EMA and HMA say these products may lack the claimed active drug. They may also have harmful levels of other substances. Their joint warning of 3 September 2025 was checked on 21 August 2026.
Those signs concern the seller and how the product is sold. The purchase study needed direct laboratory analysis to check identity, purity, content, endotoxin, and live microbes. A label or supplied paper does not make those tests.
The weight-loss research hub compares measured findings across compounds. What is in the vial? explains what each test can establish. What a certificate of analysis proves covers supplied documents. The retatrutide guide covers a related GLP-1-pathway compound without ranking it as better or safer.