How to Spot a Fake Mounjaro or Ozempic Pen

Mounjaro (tirzepatide) and Ozempic (semaglutide) are prescription medications supplied in pre-filled injection pens. Counterfeit versions of both have been reported in several countries, and medicines regulators have issued safety alerts about them.

Why counterfeit weight loss pens are a safety concern

The World Health Organization (WHO) states that a falsified product may contain an incorrect dose, harmful contaminants, or unknown or substituted ingredients. An incorrect dose may also leave a patient without effective treatment.

The WHO also warns that, because these products are injected under the skin, a falsified pen can pose serious risks to health that could be life-threatening.

The UK Medicines and Healthcare products Regulatory Agency (MHRA) explains that when the manufacturing process of a pen is unknown, its sterility cannot be assured. Contents that are not sterile carry a risk of infection. Allergic reactions may also occur.

Counterfeit pens reported by regulators

The WHO issued its medical product alert on falsified Ozempic on 19 June 2024. The product had been detected in Brazil and the UK in October 2023, and in the US in December 2023. The WHO reported that it had been supplied within the regulated supply chain.

A Drug Safety Update from the MHRA, published on 24 February 2026, described five falsified Mounjaro KwikPen 15 mg pens traced to a single UK online pharmacy. Testing confirmed that the pens contained tirzepatide. Every pen identified had a faulty mechanism, often with a dose knob that came off during use. The pens were labelled with the batch number of authentic Mounjaro KwikPen 7.5 mg pens.

The MHRA had received no reports of patient harm that required treatment. It advises patients not to try to extract a dose from a pen that is defective in any way.

In the US, the Food and Drug Administration (FDA) first reported counterfeit Ozempic 1 mg pens in December 2023. Thousands of units were involved. The needles supplied with them were also counterfeit, and their sterility could not be confirmed. The FDA reported several hundred further counterfeit units in April 2025 and a smaller number in December 2025. The pens found in December 2025 carried a lot number that is also used on authentic Ozempic.

Counterfeit weight loss medication in the UAE

On 21 October 2024, the Dubai Health Authority issued Circular No. 9217 of 2024 to private health facilities in Dubai. It relayed an alert from the Ministry of Health and Prevention (MOHAP) against the use of a counterfeit medicinal product. The attached alert named Mounjaro single-dose pre-filled pens.

In July 2026, Khaleej Times reported that the Emirates Drug Establishment (EDE) had taken action against 71 violators for marketing or selling unapproved peptide-based weight loss products. They included 14 social media influencers, whom the EDE referred to the National Media Authority. The EDE urged the public to buy medicines through approved channels.

How to check your pen before injecting

The leaflet supplied with your pen describes how it should look and work. Before each injection, we recommend checking the following points.

• The outer carton is sealed and undamaged, and the patient leaflet is inside.
• The medication name, strength, batch number and expiry date on the carton match those on the pen and on your prescription.
• The expiry date has not passed.
• The medication inside the pen looks as the leaflet describes.
• The pen has no loose, cracked or missing parts and works as the leaflet describes.

These checks can identify a damaged, mismatched or tampered product. They cannot prove that a pen is authentic, because a counterfeit can carry the batch number of a real product. Our guide to storing weight loss injections explains how to keep pens in good condition once they are dispensed.

How to obtain weight loss medication safely in the UAE

The WHO advises that medical products should be obtained only from authorised or licensed suppliers. The FDA advises obtaining Ozempic only with a valid prescription from a licensed pharmacy.

We recommend obtaining weight loss medication only with a prescription issued after a medical assessment, and only from a licensed pharmacy. A product sold without a prescription, or offered through social media or a messaging app, has not passed through either of these checks.

Our articles on buying Mounjaro online in the UAE and on over-the-counter sales of Mounjaro, Ozempic and Wegovy set out the rules in more detail. Compounded products raise separate questions, which we cover in our article on compounded GLP-1 medications.

The weight loss medications available at Endocare include Mounjaro, Wegovy and Foundayo, a once-daily tablet. Ozempic is approved for type 2 diabetes, and Wegovy is the semaglutide medication approved for weight management. At Endocare, Ozempic is considered for weight management only in patients with type 2 diabetes or prediabetes. Ozempic is not approved for weight management or for prediabetes, so using it for weight management outside the treatment of type 2 diabetes, including in prediabetes, is off-label.

Patients should not decide by themselves to start a GLP-1 medication. A doctor’s review is critical to ensure the treatment is safe and appropriate for the individual.

What to do if you suspect a counterfeit pen

If you suspect that a pen is counterfeit, we recommend that you do not use it. Keeping the pen with its packaging allows your doctor or the pharmacy that dispensed it to examine both.

The WHO advises anyone who has used a falsified product, or has had a reaction to one, to seek immediate medical advice from a healthcare professional.

Difficulty breathing or swelling of the face, lips or throat after an injection requires emergency care. Call an ambulance on 998.

Frequently asked questions

How can I check whether my Mounjaro pen is authentic?

Checks at home can show whether the packaging is sealed and whether the details on the carton and the pen match. No check at home can confirm that a pen is authentic. We recommend having your prescription filled by a licensed pharmacy and comparing the pen with its leaflet before each use.

Can a counterfeit pen have a real batch number?

Yes. The falsified Mounjaro pens described by the MHRA in February 2026 carried a batch number belonging to authentic 7.5 mg pens. The FDA has also reported counterfeit Ozempic labelled with a lot number used on authentic product.

Is it safe to buy Ozempic or Mounjaro through social media in the UAE?

We recommend against it. In the UAE, weight loss injections require a prescription. A product bought through social media has not been prescribed after a medical assessment or dispensed by a licensed pharmacy.

What should I do if I have already used a pen I think is fake?

We recommend that you stop using the pen, keep it with its packaging and contact your doctor, even if you feel well. Your doctor can advise you on any symptoms to watch for. If you develop a severe reaction, such as difficulty breathing, call an ambulance on 998.