Right, the basics, what are they?

Weight loss medication in the UK now comes in two forms: weekly injections like Mounjaro and Wegovy, and, as of June 2026, a licensed once daily Wegovy tablet, the same drug, no needle required. Ozempic works the same way as the injections but is only licensed for diabetes, not weight loss. All of them work by mimicking hormones your gut already produces naturally, hormones that tell your brain you are full and slow down digestion. Most people who use them eat significantly less without feeling deprived. Weight loss follows gradually over weeks and months. They are not diet pills in the sugar pill sense, they are not stimulants, and they do not speed up your metabolism. They simply make your body better at recognising when it has had enough food.

What is the difference between them?

Ozempic contains a drug called semaglutide. It works on one hormone receptor in the body. It was originally developed for type 2 diabetes, weight loss was a side effect that turned out to be significant. In the UK Ozempic is only licensed for diabetes not weight loss. Mounjaro contains tirzepatide. It works on two hormone receptors instead of one. Because it targets more pathways it tends to produce greater weight loss. Clinical trials showed an average of around 22 percent body weight lost at the highest dose over 72 weeks. Mounjaro is licensed in the UK specifically for weight management. Wegovy is worth mentioning here too. It is semaglutide, the same drug as Ozempic but at a higher dose and specifically licensed for weight loss. Some people use Wegovy rather than Ozempic for this reason. There is also now a Wegovy tablet, MHRA approved in June 2026, which is the same semaglutide in a once daily pill instead of a weekly injection. It is not the same thing as Rybelsus, which is also a semaglutide tablet but a lower dose licensed only for diabetes. If you have seen people ask whether there is an “Ozempic pill” this is usually what they mean, there isn’t one, but Rybelsus and the Wegovy tablet are often confused with each other. If weight loss is your goal, Mounjaro, Wegovy or the Wegovy tablet are the appropriate licensed treatments. Ozempic and Rybelsus are technically for diabetes.

Do they actually work?

For most people who are eligible and use them correctly, yes, significantly. Mounjaro trials showed average weight loss of around 22 percent of body weight, and the Wegovy tablet performed similarly to the Wegovy injection in trials, around 13 to 14 percent. For someone starting at 14 stone that is roughly three stone on Mounjaro. For someone at 16 stone closer to three and a half. Results vary. Some people lose more. Some less. People who combine the medication with changes to what they eat tend to do better than those who rely on the jab or pill alone. These are not permanent fixes. Most people regain weight when they stop, as the questions above show too. That is a conversation worth having with your prescriber before you start.

What are the side effects?

Nausea is the most common, particularly in the first few weeks or after each dose increase. Vomiting, diarrhoea and constipation also occur regularly, and the Wegovy tablet has its own fasting and water rules that matter for how well it works, not just comfort. For most people these settle down as the body adjusts. Injecting in the evening and eating smaller, plainer meals helps. More seriously, in January 2026 the MHRA updated safety warnings for both Mounjaro and Wegovy after linking them to rare but fatal cases of severe pancreatitis. Severe abdominal pain that does not pass is a medical emergency. Stop your medication and get help immediately. One thing most providers do not mention: if these treatments cause dizziness or fatigue and you drive, UK law may require you to tell the DVLA. Ignoring this could result in a fine of up to £1000.

How do I actually get a prescription?

NHS: this depends which drug you’re looking at. Mounjaro was added to the GP contract in April 2026, so your own GP practice can now prescribe it directly if you meet the criteria for the initial phased rollout, a BMI of 40 or more (37.5 or more if you’re of South Asian, Chinese, other Asian, Middle Eastern, Black African or Caribbean origin) plus four weight-related conditions. Wegovy is still mainly accessed through specialist Tier 3 weight management services, BMI 35 plus one qualifying condition, or a newer pathway from April 2026 for people with a BMI of 27 or more who’ve had a heart attack or stroke. Waiting lists exist in many areas either way, and the Wegovy tablet is not yet on the NHS at all, only privately. Start by speaking to your GP about which route applies to you. Private: several regulated UK services offer online consultations and prescriptions, for both the injections and the new tablet, see our clinic reviews for a rundown of the main providers. Before using any provider check two things, both free and take under five minutes. CQC registration at cqc.org.uk and GPhC pharmacy registration at pharmacyregulation.org. If a provider cannot pass both checks do not use them.

Why do prices vary so much between clinics?

NHS prescriptions are free if you qualify. Privately, Mounjaro typically starts at around £164 to £200 per month for starter doses with reputable providers, see our full Mounjaro price comparison for up to date figures across providers. Wegovy is similarly priced. Pricing for the Wegovy tablet is still settling as it has only just launched privately, expect it to sit in a comparable range to the injection. Be cautious of anything significantly cheaper than the going rate. Counterfeit versions of both drugs, and now the tablets too, are circulating in the UK, and switching providers purely to chase a discount code is exactly the kind of behaviour counterfeit sellers rely on.

The one minute summary

Mounjaro, Wegovy and now the Wegovy tablet reduce appetite by mimicking natural gut hormones. Mounjaro tends to produce the greatest average weight loss, but individual results vary a lot. Ozempic and Rybelsus are licensed for diabetes only, not weight loss. You do not have to keep increasing your dose if a lower one is working. Side effects are real but manageable for most people. Mounjaro is now available directly through GPs for those who meet the criteria, currently a BMI of 40 or more plus four conditions; Wegovy still generally requires a specialist referral, or a newer cardiovascular pathway for some patients. The Wegovy tablet is private-only for now. Private treatment starts at around £164 a month through regulated providers. Research suggests most people regain the weight at around 0.8kg a month if they stop and don’t change anything else, so it’s worth planning for that before you start. Retatrutide is popular in patient groups but is not licensed in the UK. Always check CQC and GPhC registration before buying privately, whichever provider you pick.

This guide is for information purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any treatment.