What is the best weight loss pill for me?

There is no “best” weight loss pill for everyone. The best weight loss pill for you will depend on several things, such as how much weight you want to lose, what kind of pill you’d like to take, your budget, body mass index (BMI), other health conditions, and medications you’re currently taking.

When it comes to weight loss pills in the UK, you can find over-the-counter tablets, prescription weight loss pills, and natural weight loss tablets (supplements). In this guide, we look at which weight loss pills actually work and the different types available so you can choose what is right for you with confidence.

Weight loss pills are pills that can help you lose weight. You can get:

• prescription weight loss pills
• over-the-counter weight loss pills
• herbal or natural weight loss pills (supplements)

You may also notice that weight loss pills are sometimes called weight loss tablets. These meanings are interchangeable and refer to any weight loss medication that is swallowed. Most prescription weight loss pills require a body mass index (BMI) of 28 or above, but this depends on the treatment.

➤ Find out your BMI with our BMI calculator by entering your recent weight and height measurements.

Orlistat is a precription-only weight loss pill. Here is an overview of what's in it, how effective it is, how it works and how to take it.

Mysimba is a precription-only weight loss pill. Find out more about what's in it, how it works, how effective it is and how to take it.

Xenical is a prescription-only weight loss pill. Find out all about how it works, what's in it, how to take it and how effective it is.

ZAVA can prescribe all of these weight loss pills if suitable for you, as well as weight loss injections like Wegovy, Mounjaro, and liraglutide.

The different kinds of weight loss tablets each work in their own specific way.

Orlistat-based tablets

These work by changing how your body absorbs fat from your food. Lipase is an enzyme that breaks down the fat you eat ready to be absorbed. Orlistat is a lipase inhibitor which makes lipase inactive, reducing the amount of fat absorbed by around 30%. The unabsorbed fat is removed from the body in your stools.

Mysimba

Mysimba contains naltrexone and bupropion, which act on the part of the brain that controls your appetite. It works by suppressing your appetite so that you feel less hungry. As a result, Mysimba reduces the amount of food you need to eat to feel full, which helps to reduce habits like snacking between meals and overeating.

Many other over-the-counter weight loss tablets claim to be appetite suppressants. How each weight loss pill works will depend on the active ingredient(s).

How long do weight loss tablets take to work?

Orlistat pills start working within 2 days of starting treatment, but it may take a few weeks to notice the benefits. If you take orlistat alongside a low-calorie, low-fat diet and regular exercise, you may start to notice the results in 2 weeks. The aim is to lose 5% of your initial body weight within 12 weeks of starting any orlistat tablet, or your doctor may recommend switching to a different treatment.

Mysimba starts working right away, but it can take a few weeks to see noticeable results. If you have not lost at least 5% of your starting body weight after 16 weeks, your doctor may recommend that you stop taking Mysimba. They may suggest alternative weight loss treatments instead.

How effective are weight loss tablets?

Weight loss tablets can be an effective treatment for some people, especially when taken alongside a diet and exercise program.

This table compares the effectiveness of weight loss pills:

Here are the most popular weight loss pills and their costs if you order from ZAVA:

ZAVA can provide a range of weight loss pills along with a prescription. We are authorised and regulated by the Care Quality Commission (CQC) and are a registered pharmacy. Our doctors will check your suitability for any treatment before prescribing it and will provide follow-up advice in your free online account.

The cost of weight loss pills can vary depending on their active ingredients, whether or not they require a prescription, and where you obtain them. Branded medications tend to be more expensive than unbranded ones, such as Xenical vs orlistat.

The best over-the-counter weight loss pills may differ from person to person. The most common over-the-counter weight loss pills are alli and Orlos, which we discuss in more detail later on in this article.

There are also other over-the-counter weight loss pills you may have heard of, including Figure weight loss tablets and Prima weight loss pills. These are both now found under the branded name Liba weight loss capsules.

alli weight loss capsules contain the active ingredient orlistat, but at a lower dose of 60mg, making them a safe over-the-counter treatment. A pharmacist will still need to confirm some details with you first, such as your medical history and BMI. It’s only available if you have a BMI of 28 or above. In terms of effectiveness, alli was found to help 46.7% of people lose 5% or more of their weight after 6 months of daily use.

alli should only be taken alongside meals containing small amounts of fat up to 3 times daily. It can reduce the amount of fat you digest by around a third, which leaves your system through your stools. It may cause symptoms such as loose stools, an urgent need to use the bathroom, and gas.

Orlos weight loss tablets are another over-the-counter branded version of orlistat 60mg tablets. The active ingredient orlistat has been found to help 37% of people lose 5% or more of their starting body weight after taking it every day for 12 weeks, but it may not be as effective as 120mg prescription tablets. It should be taken with meals containing fat and works by preventing fat absorption by around a third. You can take Orlos tablets up to 3 times a day.

Orlos may cause side effects like loose stools, an urgent need to use the bathroom, and oily stools. Although they can be bought over the counter, they still need to be approved by a pharmacist who will check your BMI is above 28.

XLS-Medical offers a range of treatments that might help you lose weight. Each product is marketed as an appetite reducer, intended to fill your stomach to make you feel less hungry between meals. Their products come in the form of tablets, sachets, shakes, teas, and capsules.

These also contain natural ingredients rather than medication, such as okranol, clavitanol, and litramine, which may affect appetite and weight.

XLS-Medical can:

• be found in most pharmacies and supermarkets, as well as online
• be cheaper than prescription medication, although there are no medical studies to prove their effectiveness
• be a good choice if you do not meet the criteria for other weight loss medications or want to try a natural alternative

Potential side effects of XLS-Medical include stomach pain and flatulence.

Below, we look at the pros and cons of prescription and over-the-counter weight loss pills, so you can get a better idea of which is the right choice for you.

Each person’s weight loss journey is unique and so, the type of weight loss pill that is best for you may differ from someone else. For example, certain weight loss pills may be better than others if you’re a woman who takes the contraceptive pill. Some weight loss pills may be better for men, although there is no evidence that a weight loss pill is more or less effective depending on your gender.

If you have a busy lifestyle and would rather order weight loss pills from the comfort of your home, it may be more convenient for you to get weight loss treatment online instead, through trusted services like ZAVA.

Best weight loss pills for women on the contraceptive pill

The best weight loss pills for women depend on which you tolerate well, as side effects like vomiting and diarrhoea can reduce the effectiveness of the contraceptive pill.

Before choosing a treatment, it’s important to know that:

• orlistat very commonly causes liquid stools and an increased need to open your bowels – the manufacturer recommends using an additional method of contraception to prevent the failure of the contraceptive pill if you have severe diarrhoea
• Mysimba very commonly causes vomiting as a side effect – this can also reduce the effectiveness of your pill, usually if it happens frequently or within 3 to 4 hours of taking it
• over-the-counter treatments can still cause side effects, so check these before making a decision
• you might need to use another form of contraception while taking certain weight loss pills if you get side effects

Best weight loss pill for men

There is no best weight loss pill for men. How well a certain medication works for you will depend on several factors, including your health, lifestyle, and overall weight loss goals. However, it’s important to note that Mysimba may cause erection difficulties, though this is uncommon, while orlistat does not affect erections. If you have erectile dysfunction, you may not want to use Mysimba.

Weight loss pills can cause other side effects, so which one works best for you may also depend on how well you tolerate the active ingredients. Your doctor or pharmacist will assess whether a specific weight loss pill is safe and suitable for you to take based on your medical history.

Best weight loss pill for stomach fat

No weight loss pill specifically targets stomach fat, but they all can help lower overall body fat, which may include belly fat (visceral fat) over time. The best way to lose stomach fat, whether you take a weight loss pill or not, is to eat healthily, be in a calorie deficit, and exercise regularly. Research shows that an aerobic exercise plan alone can reduce belly fat after 12 weeks.

Best weight loss pill for diabetics

Any weight loss pill can be beneficial for diabetics, as losing weight can help improve your blood sugar levels, reduce the chances of serious complications, and if you have type 2 diabetes, may even cause your diabetes to go into remission.

Before taking any weight loss pills, tell your doctor or pharmacist you have diabetes. This is because:

• before taking orlistat pills, your doctor may need to adjust your diabetes medication
• if you are prescribed Mysimba, you will need to be monitored closely for side effects if you take any blood sugar-lowering medications, like insulin or sulphonylureas

Alternatively, the weight loss injection Mounjaro is approved for both weight management and type 2 diabetes. Speak to your doctor if you think this might help you.

Best weight loss pill for hormonal weight gain

For hormonal weight gain, any weight loss pill may be helpful, but you should speak to your doctor about addressing the underlying cause first. For example, hormone replacement therapy (HRT) can help address menopause symptoms, including weight gain. Similarly, the contraceptive pill could be beneficial for controlling hormonal-triggered symptoms if you have a condition like polycystic ovary syndrome (PCOS), which can make it harder to lose weight.

Making positive lifestyle changes will be useful for any hormonal conditions and for keeping your weight within a healthy range.

Best weight loss pills for hypothyroidism

Hypothyroidism (an underactive thyroid) is a common condition where the thyroid gland does not make enough hormones, causing various symptoms, including weight gain. Before taking any weight loss pills, you should speak to your doctor about getting treatment for an underactive thyroid, as this can help to bring your hormone levels back to within a normal range and alleviate some of your symptoms.

If you have hypothyroidism, it’s important to tell your doctor before they prescribe any weight loss medication. If you’re taking levothyroxine (a medication for an underactive thyroid), orlistat medications can interact with it. So, you may need to take them at different times, or your dose may need to be adjusted.

Weight loss pills are a type of medication that can help treat obesity. If you’re struggling to lose weight through diet and exercise, you’re not alone. Many people turn to weight loss pills to help them out.

Make an appointment with your GP to discuss your weight loss goals. Ask your doctor about what weight loss medication they recommend. They can base this on your medical history, weight loss goals, and current medications. They’ll be able to guide you toward the ones that could work best for your circumstances.

Your doctor can also create a weight loss management plan with you, which may include prescription weight loss pills if you meet the criteria for taking them. If you’d prefer to do this without waiting for a GP appointment, you can request weight loss pills through regulated online doctor services like ZAVA.

Taking weight loss pills can increase the chance of:

• being in danger due to taking an unregulated treatment – this can be avoided by speaking with a doctor or pharmacist or getting a prescription-only medication
• pancreatitis or gallstones (orlistat tablets)
• problems with your stomach and digestion (orlistat and Mysimba)
• a severe allergic reaction (anaphylaxis) in rare cases (orlistat and Mysimba)

Very common side effects of orlistat weight loss pills (orlistat, Xenical, alli) include:

• headache
• stomach pain or discomfort
• an urgent or increased need to poop
• wind with or without discharge
• oily discharge from the anus
• oily or fatty stools
• diarrhoea
• incontinence
• low blood sugar (in people with type 2 diabetes)
• cold or flu symptoms

Very common and common side effects of Mysimba include:

• nausea and vomiting
• constipation
• stomach pain
• dry mouth
• headache
• anxiety
• dizziness or feeling like the room is spinning
• difficulty sleeping – avoid taking Mysimba close to bedtime
• tiredness and low energy
• hot flush
• ringing in the ears
• increased blood pressure
• increased heart rate
• irregular heart beat
• hair loss
• rash or itchy skin
• sweating
• irritability
• feeling jittery
• tremor
• taste changes

Which weight loss tablet has the least side effects?

alli has the fewest potential common side effects, mainly because it's a lower dose than the other treatments and is available without a prescription. All weight loss tablets can cause side effects, but whether you get them will depend on how your body reacts to their active ingredients.

Who should not take weight loss pills

You should not take weight loss pills if you:

• have not been prescribed them or have not spoken to a doctor or pharmacist first
• have severe health conditions, such as liver disease, heart problems, or kidney problems
• are under 18
• might be pregnant, are pregnant, or breastfeeding.
• are taking antidepressants (if you want to take MySimba)
• are diabetic – you’ll need to speak to your doctor first to make sure they will not affect your blood sugar levels
• have a condition that means you cannot absorb or digest your food properly, such as malabsorption syndrome (only for orlistat-based products)

Before using any weight loss pills, make sure you’ve discussed your medical history and current medications with a healthcare professional. This is to make sure they will not interact with how your medications work or pose a danger to your health.

Generally, Mysimba is easier to take than orlistat, Xenical, or alli because it:

• does not require you to take it at mealtimes with meals that contain fat
• does not require you to split your fat evenly across 3 meals, though you should still be following a healthy, balanced diet with low fat
• is taken twice a day (once you reach week 2 of the dosage plan), which may be easier for some people to remember than up to 3 times a day, like orlistat-containing pills
• is a small round tablet, which may be easier to swallow than orlistat capsules, which are slightly larger and longer

This does not mean that Mysimba is better than orlistat, but if you struggle to swallow pills, for instance, Mysimba may be easier for you. Your weight loss tablets come with advice on how to take them included in the patient information leaflet, and further information can be found on your prescription. Always take your medication as advised by a doctor or pharmacist.

How to take orlistat, Xenical, and alli

You should take orlistat or Xenical:

• as a single capsule, swallowed whole with water
• with each of your 3 main meals per day, only if they contain fat
• immediately before, during, or up to 1 hour after the meal

Xenical and orlistat are safe to take long-term, and people have been studied taking Xenical for as long as 4 years. You should not double-dose alli to match orlistat or Xenical doses. This is a prescription-only dose, so if you feel like you need a higher dose, speak to your doctor or complete a consultation on our website.

The usual starting dose for Mysimba is 1 tablet, taken once daily in the morning. The dosage will slowly increase as follows:

• week 1 – 1 tablet once a day in the morning
• week 2 – 2 tablets every day, 1 in the morning and 1 in the evening
• week 3 – 3 tablets per day, 2 in the morning and 1 in the evening
• week 4 onwards – 4 tablets each day, 2 in the morning and 2 in the evening

The maximum dose of Mysimba is 4 tablets per day, 2 in the morning and 2 in the evening. Ideally, Mysimba should be taken with food, and you should avoid excessive alcohol consumption as this can increase the risk of seizures or mental disorders.

For more information on Mysimba, take a look at our Mysimba dosage information page.

Choosing the best weight loss pill for you depends on how you’d like it to work, your medical history and medications, and your budget. You’ll also need to know your current weight, as prescription weight-loss pills require a BMI of 28 and above. To get the most from any weight loss tablet, you should follow a diet and exercise plan.

If you’re still not sure which weight loss pill is right for you or which you’d like to try, speak to your GP or one of our doctors. They can help you create a tailored weight loss plan to reach your weight loss goals.

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