Mounjaro Recall: Fake Pens Alert - Check Batch Number
A safety alert has been issued for Mounjaro users after counterfeit versions of this popular weight loss injection were supplied to the public. The Medicines and Healthcare products Regulatory Agency (MHRA) announced the recall on Tuesday, February 24, targeting falsified Mounjaro KwikPens that fail to meet safety standards. This incident underscores the growing risks of counterfeit GLP-1 medications in the weight management space.
What Triggered the Mounjaro Safety Alert?
The problem surfaced when an online pharmacy, the Private Pharmacy Clinic in Birmingham, distributed fake Mounjaro pens. Eli Lilly and Company Limited, the manufacturer of authentic Mounjaro, alerted the MHRA after receiving five reports of faulty pens. In all instances except one, the dose knob detached during use, highlighting clear defects.
The alert applies specifically to the solution for injection in pre-filled pens. Importantly, Mounjaro KwikPen 7.5mg pens with this batch code are not affected. Tests on the counterfeit products confirmed they contain tirzepatide, the active ingredient in Mounjaro—a dual GLP-1 and GIP receptor agonist used for weight management and type 2 diabetes. However, the unknown manufacturing process means sterility cannot be guaranteed, posing serious health risks for injectable drugs.
Affected Mounjaro Products
The MHRA has identified specific batches of Mounjaro KwikPens as counterfeit. Users should immediately check the batch number and strength on their pens. Five of the affected pens were traced to the Private Pharmacy Clinic. While exact batch details are outlined in the official MHRA alert, the key message is clear: verify your supply source and packaging integrity.
How Mounjaro Works and Why Authenticity Matters
Mounjaro (tirzepatide) mimics gut hormones to regulate blood sugar, slow gastric emptying, and reduce appetite, leading to significant weight loss in clinical trials. As a weekly subcutaneous injection, it requires precise dosing via pre-filled KwikPens. Counterfeits disrupt this reliability: even if they contain tirzepatide, non-sterile conditions can introduce contaminants, turning a beneficial therapy into a potential hazard.
Health Risks of Counterfeit Mounjaro Pens
Because these fake pens are injectable and their sterility is unverified, there is a potential risk of infection and allergic reactions. The MHRA has not received reports of patients needing treatment after using these pens, but vigilance is essential.
Signs of Infection to Watch For
- Redness, swelling, or warmth around the injection site
- Pain or discomfort at the injection site
- Fluid leakage from the injection site
- Mild fever, chills, fatigue, or sore throat
Signs of Allergic Reaction
- Rash
- Itching
- Breathing difficulties
Anyone experiencing these symptoms should seek immediate medical attention. For those monitoring side effects from legitimate Mounjaro use, tools like Shotlee can help track injection site reactions or symptoms systematically.
Official Guidance from MHRA Chief Safety Officer
Dr. Alison Cave, Chief Safety Officer at the MHRA, stated: "Check the batch number and strength of your KwikPen. If you have one of the affected pens, stop using it straight away. Please report it to the MHRA by emailing info@mhra.gov.uk. Please include 'Mounjaro Pens' in the subject line. Keep the pen in a safe place."
She added: "If you have administered injections using the pen already, please be reassured that, based on the cases reviewed to date, the risk to you is low. Testing has confirmed that the identified fake pens do contain tirzepatide, the active substance in Mounjaro, but because the manufacturing conditions are unknown, we cannot confirm that the contents are sterile."
"If you are unsure of how to identify the pen, or are unsure on whether you have administered an affected product and have any questions, please speak to a healthcare professional."


