Blog
Weight Loss Medication Options: A Guide to the Latest Treatments
The number of prescription weight loss medications on the market, and in the news, has grown quickly over the past few years. Mounjaro and Wegovy are already well established, oral semaglutide is expanding treatment choices further, and Foundayo has just been authorised as a new option in the UK. If you are trying to make sense of how these medicines relate to one another, and which might be right for you, this guide brings the main options together in one place.
At REX Pharmacy, we recommend speaking to a pharmacist before starting or switching any weight loss treatment, so your options can be assessed against your own health history and goals.
Quick Answer
Mounjaro, Wegovy, and Foundayo all belong to the GLP-1 class of medicines, which work by mimicking hormones that regulate appetite and fullness. Mounjaro and Foundayo are both made by the same manufacturer, Eli Lilly, though they work in slightly different ways. Wegovy is made by Novo Nordisk and has the longest track record of the group. Foundayo has been authorised in the UK but is not yet available on the NHS or through routine pharmacy supply.
- Mounjaro (tirzepatide) and Foundayo (orforglipron) are both Eli Lilly medicines
- Wegovy (semaglutide) is made by Novo Nordisk
- Mounjaro and Wegovy are established, prescription only injections
- Foundayo is a newly authorised tablet, not yet available for prescription in the UK
Understanding GLP-1 Medicines
Most of the newer weight loss medications belong to a class known as GLP-1 receptor agonists. GLP-1, or glucagon-like peptide-1, is a hormone your gut releases naturally after eating. It signals to your brain that you are full, slows down digestion, and helps reduce appetite. Medicines in this class mimic that hormone, which is why they can support weight loss and, in some cases, improve blood sugar control in people with type 2 diabetes. Mounjaro goes a step further by also acting on a second hormone receptor, GIP, which is thought to add to its effect.
Mounjaro (Tirzepatide)
Mounjaro is manufactured by Eli Lilly and was originally developed for type 2 diabetes before being approved for weight management. It is described as a dual agonist because it targets both GLP-1 and GIP receptors. This dual action is thought to be behind the strong appetite suppression and blood sugar improvements many patients experience.
- Once-weekly subcutaneous injection
- Starting dose of 2.5mg, increasing to a maximum of 15mg
- Trial data suggests average weight loss of up to around 20 percent of body weight at the highest dose
- Common side effects include nausea, diarrhoea, reduced appetite, and fatigue
Wegovy (Semaglutide) Injection
Wegovy is manufactured by Novo Nordisk and has been used for weight management since 2021, building on the same active ingredient used in Ozempic for diabetes. It works by slowing gastric emptying and signalling fullness to the brain.
- Once-weekly subcutaneous injection
- Starting dose of 0.25mg, increasing to a maximum of 2.4mg
- Trial data suggests average weight loss of up to around 15 percent of body weight at the highest dose
- Common side effects include nausea, constipation, diarrhoea, and headache
Wegovy Pills (Oral Semaglutide)
An oral tablet version of semaglutide has also been developed, offering a needle-free daily alternative to the injection for people who dislike injections or want a different routine. It works on the same underlying mechanism, slowing digestion and reducing appetite, but is absorbed through the stomach lining rather than delivered under the skin. Availability and licensing for weight management can vary and change over time, so UK availability of the oral pill should always be confirmed with a pharmacist rather than assumed.
- Taken once daily, where available
- Must generally be taken on an empty stomach with a small amount of water, with a wait before eating, drinking, or taking other oral medicines
- May suit people who prefer to avoid injections
- Absorption can be somewhat less predictable than the injectable form
Foundayo (Orforglipron)
Foundayo is the newest name on this list. It was authorised by the Medicines and Healthcare products Regulatory Agency (MHRA) on 10 August 2026, making the UK the first country in Europe to approve it, for both weight management and type 2 diabetes. It is manufactured by Eli Lilly, the same company behind Mounjaro, although the two medicines are not identical and work through slightly different formulations.
One notable feature of Foundayo is that, unlike the Wegovy pill, it does not need to be taken on an empty stomach or with any particular food or water restrictions, which may make it more convenient day to day, once it becomes available.
- Once-daily tablet, taken at any time of day
- No food or water restrictions
- Dosing begins at 0.8mg and is gradually increased through several dose levels, up to 17.2mg, with a minimum of one month at each level
- Common side effects include nausea, constipation, diarrhoea, vomiting, indigestion, and abdominal pain
- Not currently available via the NHS or routine UK pharmacy supply. Authorisation is only the first step, and further evaluation, including review by the National Institute for Health and Care Excellence (NICE), will typically be needed before NHS pathways are established
Because Foundayo is so new, it cannot currently be prescribed or dispensed by pharmacies, including ours. Anyone offering it for sale outside of a registered pharmacy with a genuine prescription should be treated with caution, as this would fall outside the legal and safe supply route for a prescription only medicine.
Side-by-Side Comparison
| Feature | Mounjaro | Wegovy (Injection) | Wegovy Pill | Foundayo |
|---|---|---|---|---|
| Active ingredient | Tirzepatide | Semaglutide | Semaglutide | Orforglipron |
| Manufacturer | Eli Lilly | Novo Nordisk | Novo Nordisk | Eli Lilly |
| Mechanism | Dual GLP-1 and GIP agonist | GLP-1 agonist | GLP-1 agonist | GLP-1 agonist |
| Form | Weekly injection | Weekly injection | Daily tablet | Daily tablet |
| Food/water restrictions | None | None | Empty stomach, wait before eating/drinking | None specified |
| Max dose | 15mg weekly | 2.4mg weekly | Varies by product | 17.2mg (tablet dose) |
| UK availability | Available on prescription | Available on prescription | Confirm with pharmacist | Authorised, not yet available for prescription |
Weight loss figures have not been repeated in this table because they come from separate trial programmes for each medicine, rather than head-to-head studies, so direct percentage comparisons risk being misleading. Trial data for Mounjaro comes from the SURMOUNT programme and for Wegovy from the STEP programme. Full UK trial and efficacy data for Foundayo should be reviewed via official sources, including the MHRA’s announcement, as further detail becomes available.
Curious how these medications might apply to your own goals? Use our calculator below, or get in touch with our team via our contact page for a personalised assessment.
Frequently Asked Questions
Are Mounjaro and Foundayo the same medicine?
No. They are made by the same manufacturer, Eli Lilly, but they are different medicines with different active ingredients and formulations. Mounjaro is an injection (tirzepatide) and Foundayo is a tablet (orforglipron).
Can I get Foundayo on prescription right now?
Not yet. Foundayo has been authorised by the MHRA, but it is not currently available through the NHS or through routine UK pharmacy supply, including at REX Pharmacy.
Is the Wegovy pill available in the UK?
Availability can vary and change, so this should always be confirmed directly with a pharmacist rather than assumed. Where available, it offers a needle-free alternative to the Wegovy injection.
Which medication is right for me?
This depends on your health history, any existing conditions such as type 2 diabetes, your tolerance for side effects, and your preference for tablets versus injections. A pharmacist consultation can help match you to the most suitable, currently available option.
Are these medicines safe to buy without a prescription?
No. All of the medicines discussed here are prescription only medicines and should only be obtained from a registered pharmacy with a valid prescription. Buying from unregulated sellers carries serious health risks.
Making Sense of Your Options
With multiple GLP-1 medicines now on the market or on the way, it can help to think of them less as competing products and more as a growing set of tools, each with its own profile of benefits, side effects, and practicalities. Mounjaro and Wegovy remain the two established, available options in the UK today. Wegovy pills may offer a needle-free alternative where accessible. Foundayo represents the next step in this field, bringing a once-daily tablet with fewer dosing restrictions, though it is not yet something that can be prescribed while NHS evaluation and supply arrangements are put in place.
- Mounjaro and Wegovy are established, available, prescription only treatments
- Mounjaro and Foundayo share a manufacturer but are different medicines
- Wegovy pill availability should be confirmed with a pharmacist
- Foundayo is authorised but not yet available for prescription in the UK
Ready to discuss which option might suit you today? Our team at REX Pharmacy is here to help.
You can also get in touch with us if you have any questions before booking.
