Tirzepatide SPC: what the Summary of Product Characteristics actually tells you

The SPC is not a patient leaflet, and that confusion matters

Many people searching for the tirzepatide SPC are actually looking for the Patient Information Leaflet (PIL), and the two are easy to mix up. They come from the same regulatory submission, but they serve different audiences. The PIL is the folded document inside your Mounjaro box, written for patients. The SPC is written for healthcare professionals: it uses clinical terminology, lists adverse-event incidence rates from trial data, and states contraindications in the technical language that prescribers are trained to interpret.

Reading the SPC cold, without clinical training, can be alarming. The adverse-effects section reports every event that reached a statistically meaningful threshold in the trials, including rare ones. That does not mean you will experience them. If you have read the Mounjaro SPC on the eMC and have questions about what applies to you, the right move is to bring those questions to your prescriber, not to interpret the frequency tables alone.

For straightforward patient-level information, the NHS tirzepatide medicines page translates the key SPC facts into plain English and is a good first stop. The SPC itself sits alongside it as the definitive clinical reference.

What the SPC confirms about the licensed indication and who qualifies

The SPC states that tirzepatide is licensed in the UK as an adjunct to a reduced-calorie diet and increased physical activity for adults with an initial BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related comorbidity such as hypertension, type 2 diabetes, dyslipidaemia or obstructive sleep apnoea. BMI alone does not determine prescribing. Contraindications, current medicines, personal and family medical history, and the prescriber's clinical assessment all feed into the decision.

The SPC also covers tirzepatide's licence for type 2 diabetes management, which has a different dosing context. If you are exploring whether Mounjaro or tirzepatide refers to the same product in different contexts, the short answer is yes: Mounjaro is the brand name under which tirzepatide holds both licences in the UK.

The Mounjaro SPC is explicit that tirzepatide is not licensed for under-18s, during pregnancy, or during breastfeeding. Women of childbearing potential should discuss contraception with their prescriber before starting; the document references reduced oral contraceptive absorption during the first four weeks at each dose level, which has practical implications. None of that is buried in small print, it is in the contraindications and special-populations sections, which any prescriber working with this medicine is expected to know in full.

The dosing schedule in the SPC: what it says and what it does not decide for you

The SPC defines the starting dose as 2.5 mg once weekly. The first four weeks exist primarily to let your body adjust; that starter pen is not expected to drive significant weight loss on its own. Subsequent dose steps (5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg) each require a minimum of four weeks at the previous level before the prescriber considers moving up. The SPC sets these minimum intervals; your prescriber decides whether to follow the standard schedule or hold at a well-tolerated dose for longer, based on your response and tolerability.

The SPC does not tell you which dose you should be on. That is the prescriber's call, reassessed at every supply. If you are thinking about what a titration journey looks like in practice, the tirzepatide dosing and titration overview covers the practical side without straying into instruction territory. For context on the highest available dose, the information on the 15 mg pen explains what the trial data showed at that level.

Storage requirements are in the SPC too. Mounjaro pens are refrigerated at 2–8°C. There is a limited window during which a pen may be kept at room temperature, the exact duration is stated in the SPC and PIL, and those are the only sources you should rely on for that figure. Anyone planning to travel, or wondering whether a pen left out over a bank holiday weekend is still usable, should check the leaflet directly or ask a pharmacist. It is one of those questions that comes up around long weekends and summer holidays more than you might expect.

Side effects, reporting, and the Black Triangle

Mounjaro carries a Black Triangle (▼) symbol in the UK, which the SPC states prominently. This designation means the MHRA requires additional monitoring because the medicine is relatively new; it does not indicate unusual danger. The triangle is removed once enough real-world safety data has accumulated.

The SPC groups adverse reactions by system and frequency. The most common are gastrointestinal: nausea, loose stools, constipation, indigestion, reflux and belching appear at the top of the list. Fatigue, headache, dizziness and injection-site reactions are also listed. Most GI effects are reported as worst in the early weeks or after a dose increase, then easing. The SPC identifies acute pancreatitis as a known but infrequent serious risk; in January 2026 the MHRA issued a specific Drug Safety Update on this, advising that severe or persistent stomach pain spreading to the back warrants urgent medical assessment, regardless of whether vomiting accompanies it.

Patients can report suspected side effects directly to the MHRA using the Yellow Card scheme, and that reporting is valuable, it feeds into the ongoing safety review that determines when the Black Triangle is eventually retired. If you have questions about a specific side effect and how it relates to your situation, our prescribers are available seven days a week through aftercare support.

For anyone at the stage of deciding whether to start treatment, a free consultation with our clinical team is the right next step. A real prescriber reviews your answers the same day, and the SPC is one of the documents informing that review.