Are weight loss injections safe?

GLP-1 medications have been studied in large clinical trials and are approved by the MHRA and NICE. However, they carry risks including pancreatitis. Always use under medical supervision.

Safety & Side Effects

Quick Answer

GLP-1 medications have been studied in large clinical trials and are approved by the MHRA and NICE. However, they carry risks including pancreatitis. Always use under medical supervision.

Detailed Answer

GLP-1 weight loss medications including Mounjaro, Wegovy, and Saxenda have been studied in extensive clinical trial programmes involving tens of thousands of participants. They have been reviewed and approved by the Medicines and Healthcare products Regulatory Agency (MHRA) and recommended by NICE for use in the UK.

The safety profiles established in clinical trials are generally favourable. The most common side effects are gastrointestinal (nausea, diarrhoea, constipation) and are usually mild to moderate. Serious adverse events were rare in clinical trials.

However, like all prescription medications, GLP-1 agonists carry potential risks that must be carefully considered. The MHRA has issued specific guidance highlighting the following concerns:

Pancreatitis: GLP-1 medications carry a small risk of acute pancreatitis. Patients should seek immediate medical attention for severe, persistent abdominal pain. Gallbladder problems: Rapid weight loss can increase the risk of gallstones. Mental health: The MHRA is monitoring reports of psychological side effects including changes in mood, anxiety, and suicidal thoughts, though a causal link has not been established.

The key to safe use is obtaining medication through a legitimate, GPhC-registered provider who conducts a proper medical consultation, and maintaining regular contact with your prescriber throughout treatment. Buying medication from unregistered sources or without a medical consultation is unsafe.

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Important Medical Information

This website provides general information about weight loss medications for educational purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult your GP or qualified healthcare professional before starting any weight loss medication. Individual results may vary.

WhichWeightMeds.org is an independent comparison platform and is not affiliated with any pharmacy, manufacturer, or healthcare provider. We do not prescribe, sell, or dispense medications.

Sources & References

  1. 1
    GLP-1 medicines for weight loss and diabetesMHRA (Accessed February 2026)View source
  2. 2
    Tirzepatide for managing overweight and obesity (TA1026)NICE (Accessed February 2026)View source