Can Mounjaro be used with other weight loss medications?

Mounjaro (tirzepatide) is generally not used alongside other prescription weight-loss medicines such as semaglutide (Wegovy), liraglutide (Saxenda), or orlistat. UK guidance recommends using one licensed medicine at a time within a supervised weight-management plan because combination therapy has not shown added benefit and may increase side effects. Public health advice in the UK also stresses that GLP-1–based medicines (including tirzepatide) should be prescribed as part of a structured programme, and mixing weight-loss drugs is not standard NHS practice. If someone is already on another weight-loss medicine, the usual approach is to switch rather than combine, with a prescriber reviewing interactions and timing to minimise issues such as gastrointestinal side effects or altered absorption of other medicines. For over-the-counter options like orlistat, interaction resources flag at least a moderate interaction risk when used with tirzepatide, so any combined use should only occur on a clinician’s advice with monitoring.

• Use one prescription weight-loss medicine at a time within a structured NHS plan; combinations are not recommended.
• Do not combine tirzepatide with other GLP-1–based drugs (e.g., semaglutide, liraglutide) in routine care.
• If already taking another weight-loss drug, clinicians typically consider switching rather than adding Mounjaro.
• Orlistat + tirzepatide is flagged as a moderate interaction—only consider under clinician advice with monitoring.
• Tirzepatide can affect the absorption of other medicines; prescribers review all meds and timing.

Sources

• NHS England – Weight management injections (guidance on structured programmes)
• NICE TA1026 Practical Guide – Prescribing orlistat, liraglutide & semaglutide
• MHRA Drug Safety Update – GLP-1 receptor agonists: side effects & misuse
• Drugs.com – Interaction report: orlistat + tirzepatide
• NHS England (Mar 2025) – Interim commissioning guidance implementing NICE TA1026