Weight Loss Injections

Semaglutide (Wegovy) & Tirzepatide (Mounjaro/Zepbound)

 

Wegovy belongs to a class of drugs called GLP-1 analogues, which means they have the same action as a hormone called GLP-1. This hormone is produced by cells in the bowel and results in weight loss via several mechanisms. Firstly, it signals directly to important appetite controlling centres in the brain to make you feel full sooner and reduce portion sizes. Some patients say it also changes their taste for certain foods and they no longer crave the same foods as before. It also has effects on the stomach and increases the time it takes for food to move into the bowel, hence feeling fuller for longer. It also improves how your body handles blood glucose levels and can make your more sensitive to your insulin levels made by the pancreas. Wegovy is the same medication as Ozempic which is licenced for use in patients with Type 2 diabetes. It is simply given a different name as the dose is slightly different when used in weight loss and to avoid confusion. 

 

Tirzepatide (also known as Mounjaro or Zepbound) is similar to Wegovy but as well as acting as a GLP-1 analogue, it also acts like another hormone produced in the bowel called Glucose-dependent Insulinotropic Polylpeptide (GIP). At HealthyMe we offer both forms of weight loss injections, Wegovy & Mounjaro/Zepbound, via the Nuffield Health Guildford Hospital. 

 

Medications are​ self-administered once weekly by injection (under the skin in the abdomen) using a pre-filled pen. It is easy to use and online video tutorials can be used to guide you: https://www.wegovy.com/taking-wegovy/how-to-use-the-wegovy-pen.html

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How much weight will I lose with weight loss injections?

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Clinical trials have found that patients tend to lose between 10-20% of their body weight at one year on Wegovy. Some patients lose more, others less and a minority do not respond at all. The starting dose is 0.25 mg which is prescribed for one month, followed by 0.5 mg for two months. At three months you will be reviewed by the bariatric physician and if you wish to continue with the programme, then a dose of 1mg is prescribed for 3 months. Higher doses are occasionally available however are more expensive and tend to cause significant side-effects. ​

 

Clinical trials suggest that Mounjaro/Zepbound is better at treating obesity with an average weight loss of around 20-30%. It is taken as a once weekly injection in the same way as Wegovy, and doses range from 2.5mg to 15mg. 

 

What are the side effects of weight loss injections?

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Common side-effects include nausea and gastrointestinal upset. This can include vomiting, diarrhoea, constipation, and headaches. However, all of these side-effects tend to be self-limiting and usually resolve within 1-2 weeks. Occasionally, patients request anti-nausea medication which can be supplied at an additional cost. 

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There are rarer, more serious side-effects, including pancreatitis. This causes severe central abdominal pain and usually requires hospital admission. Therefore, any patient with a history of pancreatitis would not be advised to take this class of medication. 

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Another contra-indication to this class of drugs would be a very rare form of thyroid cancer called, medullary thyroid cancer. Please inform your Bariatric Physician if you have a family history of this cancer. 

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From a psychological aspect, there are some reports of effects on mood, although this is still under clinical review. Patients with a significant past medical history of mental health disorder will be encouraged to see our psychologist prior to starting treatment. 

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