Best weight loss pills in the UK

There’s more choice than ever when it comes to legitimate weight loss pills. But if you are considering weight loss tablets, it’s important to understand that not all options work in the same way, and not all treatments deliver the same results.

Some pills focus on reducing how much fat your body absorbs, while others work on your brain to help control appetite and cravings. Newer tablets in development are taking this a step further by targeting the hormones that regulate hunger.

In this guide, we’ll help you find the best weight loss pill for your body. We break down how weight loss pills work, how effective they are, and how to choose the right option for you.

Key points

• Newer tablets can support up to 22% weight loss, depending on the treatment and how consistently it’s used alongside diet and exercise.
• They work in different ways, from reducing food noise and making you feel fuller for longer (Wegovy pills) to blocking fat absorption (orlistat).
• More weight loss tablets may be on the horizon, with Foundayo currently being reviewed by the MHRA.

Best weight loss tablets at a glance

Currently available

Waiting for approval - info from clinical trials only

How do weight loss pills work?

Not all weight loss pills work in the same way, as they don’t all have the same active ingredients. Think how paracetamol and ibuprofen, work in different ways to manage your pain, despite both being ‘painkillers’.

Certain weight loss tablets, like Wegovy tablets and Foundayo, belong to a group of medications called GLP-1 receptor agonists. This is because their active ingredients, semaglutide and orforglipron respectively, mimic the hormone in your body that regulates appetite, helping reduce food noise and keeping you fuller for longer. It also means they work in the same way as weight loss injections like Mounjaro and Wegovy.

Other tablets like Xenical, Orlos and Alli all contain the same active ingredient, orlistat, so all behave similarly. Orlistat is a type of medication known as a ‘lipase inhibitor’, which works by blocking the chemicals in your gut responsible for digesting fats. This means these fats aren’t stored as energy and instead are passed in your stool.

Finally, Mysimba works by combining two active ingredients, bupropion (norepinephrine-dopamine reuptake inhibitor or NDRI) and naltrexone (an opioid antagonist). Together, these work by targeting the areas of the brain that regulate your appetite and desire for food, making it easier to stick to smaller portions and a calorie-controlled diet.

What are the most effective weight loss tablets?

Choosing a medication to help with weight loss is an individual decision, supported by your clinician. That’s because there are many factors that can make one better for you than the rest, from side effects to price to availability.

Below we take a look at all the weight loss tablets currently available in the UK, and how they performed during clinical trials:

Wegovy tablets (semaglutide)

Patients using Wegovy pills lost an average of 17% body weight over 64 weeks during the OASIS-4 clinical trial. However, early responders (those that lost 10% of starting body weight by week 16) on average lost 22% by the end of the trial.

Xenical (orlistat)

Prescription-strength orlistat, like Xenical, has been observed to be an effective and well-tolerated drug to help manage obesity. In clinical trials, it helped with a significant reduction in weight compared to placebo, offering an average weight loss of 5-10%.

Mysimba

The other prescription weight loss tablet currently available in the UK, Mysimba, has a similar effectiveness to orlistat, showing 5-10% weight loss in clinical trials.

Alli (orlistat)

People taking Alli alongside a reduced-calorie diet and exercise lost about 3-5% of their body weight over 12 months during clinical trials.

Even though it has the same active ingredient as Xenical, the lowered dose means that it’s not as effective overall. However, it does have the benefit of being available over the counter, rather than prescription-only.

Are other weight loss tablets in development?

Foundayo has been approved in the USA and is currently being reviewed by the Medicine and Healthcare products Regulatory Agency (MHRA).

During clinical trials, patients using Foundayo saw average weight loss of 7-11%.

The potential benefits of Foundayo extend past weight loss, however, as it’s claimed that it’s the only once-daily oral weight loss treatment that can be taken at any time of day, with or without food.

Weight loss tablets eligibility

Weight loss tablets are typically prescribed based on clear clinical criteria rather than personal preference alone.

For most treatments, eligibility starts with your Body Mass Index (BMI). In general, weight loss tablets may be considered if your BMI is:

• 30 or above, which falls into the obese category
• 28 or above with weight-related health conditions, such as high blood pressure, type 2 diabetes or high cholesterol

You’ll usually also need to have already tried to lose weight through diet, exercise and lifestyle changes before medication is recommended.

Who shouldn’t use weight loss pills

Weight loss tablets aren’t suitable for everyone, and there are certain situations where they should be avoided or only used with medical advice.

You should not use weight loss tablets if you:

• are pregnant or breastfeeding
• have certain medical conditions, such as malabsorption disorders or uncontrolled high blood pressure, depending on the treatment
• have a history of eating disorders, particularly with treatments that affect appetite
• are taking medications that may interact with weight loss tablets

Because different tablets work in different ways, what’s unsuitable for one person may still be safe for someone else. A prescriber will always check your medical history and current medications before recommending a suitable option.

Are weight loss tablets as effective as injections?

Weight loss tablets can be very effective for some, but during clinical trials they historically haven’t led to the same level of weight loss as injectable treatments.

In the UK, most tablets like orlistat and Mysimba tend to support around 5–10% body weight loss when used alongside diet and exercise. On the other hand, injections like Wegovy and Mounjaro can potentially help patients lose an average 22.5% to 25% of their body weight.

This difference comes down to how the medication is absorbed and how strongly it affects appetite. Injections deliver the drug directly into the body, helping it work more consistently, whereas tablets need to be digested first, which can reduce how much is absorbed.

That said, tablets can still play an important role in your journey. Not everyone wants to lose more than a fifth of their starting weight. And tablets can be easier to take while still producing significant weight loss. They can even help you maintain your weight after you’ve reached your goal.

How to choose the best weight loss tablet for your body

There isn’t a single ‘best’ weight loss tablet, as the right choice depends on your body, your goals, and your medical history.

When choosing a treatment, a few key things to consider include:

• How much weight you’re aiming to lose: Some options, like orlistat, support gradual weight loss, while others like Mysimba may work by reducing appetite.
• How the medication works: For example, orlistat works in your gut to block fat absorption, while Mysimba works in the brain to reduce hunger and cravings. One may suit you better depending on your eating habits.
• How easy it is to stick to: Some tablets need to be taken with meals or follow specific routines, so it’s important to choose an option that fits your day-to-day life.

If you’re unsure where to start, speaking to a prescriber can help you find the option that’s most likely to work for you long term.

Frequently asked questions about the best weight loss pills

What is the best weight tablet pill for women?

There isn’t a single ‘best’ weight loss tablet specifically for women. Instead, the right option depends on how your body responds and what kind of support you need.

Hormonal changes, e.g. during menopause, can make weight loss feel more difficult, but this doesn’t always mean you need a different medication.

Ultimately, the best weight loss tablet is the one that fits your lifestyle, is safe for you to take, and helps you stick to long-term changes.

Can you take weight loss tablets during menopause?

Yes, you can safely take weight loss tablets during menopause. While most weight loss tablets are fine, you should look to avoid over the counter ‘fat burners’.

These often rely on stimulants like caffeine, which can increase anxiety, disrupt sleep and increase heart rate, all of which that may be symptoms struggled with already during menopause.

Can you drink alcohol on weight loss tablets?

While it’s recommended to limit your alcohol intake, you can drink alcohol while taking most weight loss tablets.

When drinking you may be more likely to eat fatty foods which can sometimes make gastrointestinal side effects like diarrhoea more likely or worse.

Importantly, it’s recommended not to drink alcohol on Mysimba as it can increase risk of more serious side effects.

Is Rybelsus used for weight loss?

Rybelsus is not licensed as a weight loss treatment in the UK, though it may sometimes be prescribed off label to treat weight loss.

It’s approved as a type 2 diabetes medication that lowers blood sugar levels and regulates insulin.

Can I switch between injections and tablets?

If you're taking weight loss injections and are thinking about switching to tablets, you should first speak to your prescribing pharmacist, as any changes to your treatment should always be done under clinical guidance. For more information about switching from Wegovy injections to Wegovy pills specifically, including which dose you'll need to start on, read our guide.

Sources

• Naltrexone–bupropion (Mysimba) in management of obesity: A systematic review and meta‐analysis of unpublished clinical study reports. PubMed. [Accessed 19 May 2026]
• Evaluation of efficacy and safety of orlistat in obese patients. PubMed. [Accessed 19 May 2026]
• Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity. NEJM. [Accessed 19 May 2026]
• Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial (2025). PubMed. [Accessed 19 May 2026]
• Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (2025). PubMed. [Accessed 19 May 2026]
• Alli (previously Orlistat GSK). EMA. [Accessed 19 May 2026]
• Orlistat 60 mg Reduces Visceral Adipose Tissue: A 24-Week Randomized, Placebo-Controlled, Multicenter Trial. Wiley Online Library. [Accessed 19 May 2026]
• From pen to pill: How our scientists cracked a 100-year-old medical puzzle (2026). Novo Nordisk. [Accessed 8 June 2026]
• Early Responders to Oral Semaglutide 25 mg: A Post Hoc Analysis of the OASIS 4 Trial (2026). Novo Nordisk. [Accessed 8 June 2026]