Weight loss that holds

Nobody can tell you your number in advance, and be wary of anyone who tries. What the clinical trials found, at the highest dose studied, alongside diet and activity support:

• Mounjaro (tirzepatide 15 mg, 72 weeks) — 20.9% average weight loss
• Wegovy (semaglutide 2.4 mg, 68 weeks) — 14.9%
• Wegovy Pill (oral semaglutide 25 mg, 64 weeks) — 13.6%
• Foundayo (orforglipron 36 mg, 72 weeks) — 11.1%

Those are averages across everyone who started, including people who stopped early, which is the honest way to read them and lower than the figures usually quoted. Some people lose considerably more. Some lose very little. Your starting weight, the dose you tolerate and what else changes alongside it all matter.

Most of the weight comes back, and it is better to know that now than in a year.

When semaglutide was withdrawn in the STEP 1 trial extension, participants regained around two-thirds of what they had lost within twelve months — finishing 5.6% below where they started, having been 17.3% down at their lowest.

That is not a failure of willpower. These medicines work while they are in your system; when they leave, appetite returns to roughly where it was. It is why we treat this as long-term management rather than a course you finish, and why the plan puts weight on the parts that outlast the medication.

Yes — both of the treatments we prescribe, Mounjaro and Wegovy, are once-weekly injections.

You give them yourself with a pre-loaded pen, and it goes into the stomach, thigh or upper arm. Your clinician can talk you through the first one.

If needles worry you, raise it in your assessment. It is a perfectly reasonable thing to ask about, and nobody here will make you feel odd about it.

For weight loss, on average, yes — and unusually for this question it has been tested directly rather than inferred by comparing separate trials. In SURMOUNT-5, a head-to-head study, tirzepatide produced 20.2% average weight loss at 72 weeks against 13.7% for semaglutide.

“On average” is doing real work in that sentence. Averages describe groups, not people, and the better-performing medicine is not automatically the better choice for you — how well you tolerate it, your other conditions and medicines, cost, and how you feel about a weekly injection all count. That is a conversation with your clinician, not a league table.

Treatment is usually considered from a BMI of 30, or from 27 if you also have a weight-related condition such as high blood pressure or type 2 diabetes. There is a BMI checker further up this page.

BMI is a starting filter, not the decision. It is a crude measure — it cannot tell muscle from fat, and it reads differently across ethnic groups — so a clinician looks at your whole picture rather than one number.

Mostly your gut, and mostly early. Nausea is the common one, along with constipation, diarrhoea, vomiting and reflux. They tend to appear when you start and each time your dose increases, and to settle as your body adjusts. Smaller portions, stopping when you are full rather than when the plate is, and going easy on rich food help more than people expect.

Less commonly these medicines can cause gallbladder problems or inflammation of the pancreas. Severe, persistent stomach pain, particularly if it goes through to your back with vomiting, needs urgent medical attention rather than a wait-and-see. Your clinician will go through the full list against your history before anything is prescribed.

Every case is read by a registered clinician. They can and do say no when treatment isn’t appropriate, that’s the point of having a clinician rather than a checkout button.

Then you’re not charged: the hold on your card is released. The clinician might suggest a safer alternative, ask for more information, or refer you back to your GP. We’d rather lose a sale than push the wrong treatment.