UK counterfeit medicine timeline

Most-recent first. Entries summarise UK-public alerts and enforcement; consult the linked MHRA sources for the original text and any subsequent updates.

2026

February 2026 — Falsified Mounjaro 15 mg KwikPens (MHRA)

MHRA alerted that falsified Mounjaro 15 mg KwikPens had reached UK patients via unlicensed online supply. Patients reported unexpected adverse reactions and inconsistent effects, consistent with the contents not being genuine tirzepatide at the stated concentration. 15 mg is the most expensive Mounjaro strength and the most attractive to falsifiers.

Full identifier guide: Fake Mounjaro pens.

Throughout 2026 — Disruption of illegal weight-loss medicine manufacturing

MHRA and partners have reported disruption of illegal manufacturing networks producing unlicensed weight-loss medicines. The pattern is unlicensed compounded GLP-1 supply marketed to UK consumers via online clinics that bypass real clinical assessment.

2025

Counterfeit Ozempic — ongoing enforcement

Sustained pressure on Ozempic supply from off-label weight-loss prescribing kept the counterfeit market active through 2025. MHRA seized counterfeit Ozempic shipments intercepted at the UK border and prosecuted online sellers. Some seized pens contained insulin rather than semaglutide — a direct hypoglycaemia risk for non-diabetic users.

‘Compounded semaglutide’ enforcement begins

MHRA began acting against UK online clinics marketing ‘compounded semaglutide’ as a cheap Wegovy alternative. The enforcement basis was unlicensed-medicine supply outside the ‘specials’ framework — see compounded peptides and UK law.

2024

Wegovy supply pressure and counterfeit surge

Wegovy supply remained constrained through 2024 as manufacturing scaled up. Counterfeit Wegovy reaching UK patients via cross-border online supply continued to feature in MHRA enforcement.

Original Ozempic counterfeit alert (UK)

Earlier in 2024 MHRA flagged the first significant wave of counterfeit Ozempic pens reaching UK patients. The same patterns — unlicensed online sellers, missing PILs, mismatched batch numbers, and in some cases insulin substitution — have recurred.

2023

Ozempic — global counterfeit reports

Global reports of counterfeit Ozempic accelerated in 2023 as the medicine became socially viral. UK enforcement and intelligence-sharing with EMA / FDA increased.

Tirzepatide UK launch (Mounjaro)

Tirzepatide launched in the UK as Mounjaro. New product, new counterfeit opportunity — falsifiers tracked the launch.

2022 and earlier

Counterfeit injectables targeting UK patients are not new. Insulin counterfeits, fake testosterone, fake hCG, and a long history of unlicensed melanotan supply all preceded the GLP-1 wave. The MHRA Criminal Enforcement Unit has been operating against this category for decades; what changed with GLP-1s was the scale of public demand and unit pricing.

Patterns across the timeline

• Falsifiers follow market opportunity. When a medicine becomes high-demand and high-margin, counterfeit supply appears within months.
• Shortages amplify the counterfeit market. Every UK shortage has produced a corresponding counterfeit surge.
• Cross-border supply is the consistent vector. EU and non-EU online pharmacies offering UK delivery have been the main counterfeit route.
• Online clinics with weak clinical assessment are how counterfeits reach prescription-driven patients.
• Insulin substitution in counterfeit GLP-1 pens is a recurring and serious pattern — an acute risk for non-diabetic users.