Frequently asked questions

• Why has the price of Mounjaro changed?

  The price of Mounjaro increased in September 2025 following a decision by its manufacturer, Eli Lilly. When Mounjaro first launched in the UK, it was deliberately priced lower than in other countries to help as many patients as possible access the treatment. Eli Lilly has since raised UK prices to bring them in line with what patients pay in Europe, the United States, and other developed countries. This decision was made solely by the manufacturer and affects every provider in the UK equally — including pharmacies, private clinics, and online platforms.

• Why are people switching from Mounjaro to Wegovy?

  There are several reasons why patients move from Mounjaro to Wegovy. The most common include cost, as Mounjaro tends to be more expensive particularly at higher doses. Some patients also switch due to Mounjaro stock shortages, side effect tolerability, or because their prescriber recommends Wegovy based on their individual health profile — particularly for patients with established cardiovascular disease, where Wegovy has strong supporting outcomes data from the SELECT trial.

• Is Wegovy as effective as Mounjaro in the long term?

  Based on current clinical trial data, Mounjaro produces greater average weight loss than Wegovy. Patients on Mounjaro lost an average of up to 22.5% of their body weight in trials, compared to approximately 21% with Wegovy 7.2mg. Switching from Mounjaro to Wegovy may therefore result in a slower rate of weight loss or a plateau, and some patients may experience modest weight regain during the transition. However, Wegovy remains a highly effective weight loss treatment in its own right.

• Will I gain weight when switching from Mounjaro to Wegovy?

  There is a possibility of some weight regain during the transition period, particularly during the Wegovy dose escalation phase. During this period the appetite-suppressing effect may be lower than you were used to on your maintenance dose of Mounjaro. Maintaining your dietary and lifestyle habits during the switch is therefore very important.

• When should I take my first Wegovy dose after stopping Mounjaro?

  As both Mounjaro and Wegovy are once-weekly injections, you should take your first Wegovy injection in place of your next scheduled Mounjaro dose. There is no washout period required between the two treatments. Your prescriber at HEBA Online Pharmacy will confirm the exact timing as part of your clinical review.

• Will the side effects be different on Wegovy compared to Mounjaro?

  Both medications share similar gastrointestinal side effects including nausea, vomiting, diarrhoea, and constipation. However, some patients who experienced more pronounced side effects on Mounjaro find Wegovy better tolerated, as Mounjaro's additional GIP receptor activity can amplify these effects in some individuals. Conversely, patients who tolerated Mounjaro well may find the side effect profile of Wegovy broadly similar.

• Can I switch back to Mounjaro from Wegovy in the future?

  Yes, switching back to Mounjaro is possible if clinically appropriate.