What Is the Strongest Weight Loss Prescription Pill?
What is the strongest weight loss prescription pill? If you came here expecting a simple answer, we have bad news. The term “strongest” is highly subjective when discussing weight loss medication.
Many pills and medicines are available for weight management. Since body types and individual needs vary, you have to find what works best for you while heeding the advice of your GP (general practitioner) or a private healthcare professional.
We’ll go over the top prescription weight loss pills, including how they work, factors to consider, and how to boost their effectiveness as part of your weight loss plan.
Top Prescription Weight Loss Pills
Below are some of the most effective weight loss pills currently available in the United Kingdom:
Xenical® (orlistat). Orlistat works by preventing the body from absorbing dietary fats. It inhibits lipase, an enzyme in the small intestine that breaks down fat molecules. This leads to reduced calorie absorption from fat intake.
Mysimba® (naltrexone-bupropion). Mysimba combines two medicines: bupropion (an antidepressant that may suppress appetite) and naltrexone, which is used to treat addiction. The combination is thought to work on brain pathways that control food intake and reward.
Alli® and Orlos® (orlistat). While not technically prescription weight loss pills, Alli and Orlos are worth knowing about. They both contain orlistat, but in lower doses than Xenical. They’re available without a prescription and are taken under the supervision of a chemist.
Another prescription pill to know about is Rybelsus®, which contains the active ingredient semaglutide. Semaglutide is also the active ingredient in the weight loss medicine Wegovy® and the diabetes medicine Ozempic®.
Rybelsus® is licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) for type 2 diabetes. In rare cases, it might be prescribed off-license for weight loss.
However, this isn’t all that common. Your GP or a private clinician is more likely to recommend a medication that is licensed for weight loss.
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What Is the Strongest Weight Loss Prescription Pill in the UK?
There isn’t any research putting weight loss prescription pills up against each other, so we don’t know precisely which is the most effective weight loss medication of the bunch.
To give you an idea, clinical trials on Xenical found that 37 percent of those taking the medicine for 12 weeks lost at least five percent of their body weight. Participants ate fewer calories than their bodies needed while taking the medicine.
For Mysimba, clinical trials found that people taking the medicine for 56 weeks lost an average of 5.4 percent of their body weight. Participants ate fewer calories and did more movement while taking the medicine.
These studies were very different, though, so we can’t compare the two medications.
What’s more, the best weight loss pill for you depends on your health, medical history, starting weight, and how your body responds to the medicine.
How Weight Loss Prescription Pills Work
Different weight loss pills work in different ways. Here are the main ways they can aid weight loss:
Appetite suppression. Many weight loss pills work by reducing hunger. Promoting satiety (a full feeling) can help prevent overeating that could lead to unintentional weight gain.
Increased metabolic rate. Some medications boost how fast you burn calories, not just when you’re moving but also while at rest.
Blocked fat absorption. Certain weight loss medicines inhibit the absorption of dietary fats by blocking the digestive enzymes that break down fat. This reduces the number of calories you absorb overall.
Hormone regulation. Some drugs target the hormones involved in hunger, appetite control, and metabolism — like leptin, ghrelin, insulin, and glucagon-like peptide-1 (GLP-1). This can help you reduce your overall food intake.
Blood sugar regulation. Some medications target blood sugar control. This can affect appetite and food cravings to support weight loss. These types of medicines are particularly helpful for people with insulin resistance or type 2 diabetes.
Who Can Take Weight Loss Pills?
Prescription weight loss pills aren’t recommended for everyone. But they can be helpful for people who haven’t had success losing weight through diet and exercise alone.
Most of these prescription medicines are reserved for people with a body mass index (BMI) of at least 30 (which is considered obesity), at least 27 (for Mysimba), or 28 (for Xenical), with at least one weight-related health condition.
Weight-related health conditions include:
Type 2 diabetes
Hypertension (high blood pressure)
High cholesterol
Heart disease
Sleep apnoea
BMI is a person’s body weight in kilograms divided by their height in metres squared. You can use the NHS’s (National Health Service) calculator to find out your BMI.
Always talk to your GP or a private care provider before pursuing weight loss medication. They can evaluate your medical needs and health goals and recommend an appropriate treatment.
Weight Loss Pills vs. Injections vs. Supplements
Weight loss treatments come in numerous forms, including pills, injections, and supplements. We’re focusing on pills in this article but want to highlight some of the differences.
Weight loss pills are taken orally and (in most cases) are appetite suppressants or fat-absorption inhibitors. They’re often supported by research and prescribed for individuals with obesity or overweight and weight-related medical conditions.
Weight loss injections are administered with a needle under the skin. Most injectable prescription medications — like tirzepatide (Mounjaro®), semaglutide (Wegovy®), and liraglutide (Saxenda®) — support weight loss by reducing appetite.
Our blog on oral vs. injectable semaglutide has more details on this.
Finally, supplements for weight loss can include various herbal extracts, vitamins, and minerals. These are typically available without a prescription and claim to support weight loss through various “natural” mechanisms. However, how well they actually work — and their safety — is questionable.
Some, like protein or fibre, may support your health as part of a holistic weight loss plan.
What About GLP-1s?
GLP-1s are a class of medications used for type 2 diabetes and obesity treatment. The majority of GLP-1s are injectables, but it’s good to understand how they work.
GLP-1s mimic the action of glucagon-like peptide-1, a hormone produced in the intestines that stimulates insulin release, slows gastric emptying (how quickly food moves on from the stomach), and reduces appetite.
By doing so, they can help regulate blood sugar levels and promote weight loss in people with diabetes and obesity or overweight.
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What to Consider When Choosing a Weight Loss Pill
When trying to answer what the strongest weight loss prescription pill is, the better question to ask is what the best option is for you.
It’s essential to think about whether the best appetite suppressant prescription is safe, effective, and appropriate for your needs. Your GP or a private healthcare professional can help you figure that out by considering your:
Medical history. Pre-existing conditions, drug allergies, any medication you’re on, or past weight loss attempts could make certain weight loss pills less effective or unsafe.
Health goals. Get specific about your weight loss goals and expectations, whether it’s to lose a specific amount of weight, improve your overall health, or manage obesity-related health issues.
Safety profile. Research the safety profile of the medication, including potentially serious side effects, warnings, and contraindications (a situation in which a medicine shouldn’t be taken — like medical problems, pregnancy, or breastfeeding).
Clinical evidence. Examine the available evidence supporting how well the pill works. Consider reviews from people who’ve used it successfully (or not).
How the medicine works. It’s important to understand how the medication works in your body to promote weight loss. Some may suppress appetite, inhibit fat absorption, increase metabolism, or affect hormones.
Long-term use. If suitable, you might take weight loss pills long-term to help with weight loss and weight management. You might need to check in with your GP or private provider regularly, especially if you’re on other medications. Make sure that fits with your lifestyle and expectations.
Cost and NHS availability. You may be able to get prescription weight loss pills through the NHS, but there are often strict eligibility criteria. If a medicine is right for you, you can also access it privately through telemedicine platforms, online chemists, or private weight loss clinics. The cost can vary with each of these routes.
Speak to your GP or a private healthcare provider about your interest in weight loss pills. They can help you evaluate the factors above and determine the best option for you.
Weight Loss Pills: Potential Side Effects
Prescription weight loss pills can be effective. But like any medicine, weight loss drugs come with potential side effects.
For example, some of the common side effects of Xenical include:
Headache
Stomach pain
Fatigue
Fatty, oily, or soft stools
Increased bowel movements
Some of the common side effects of Mysimba include:
Headache
Dizziness
Nausea
Constipation
Vomiting
Reach out to your GP or another healthcare professional right away if you experience any serious side effects.
Weight Loss Pills: Drug Interactions
Certain weight loss pills interact with other drugs. Make sure your GP or private healthcare provider knows about all the medications you’re on or any supplements you’re taking.
Due to possible drug interactions, you might not be able to take both medicines at the same time. Or your clinician may want to monitor you while you’re on both.
Xenical, for example, may interact with:
Ciclosporin. This medicine is used for conditions like severe rheumatoid arthritis, dermatitis, and psoriasis. Orlistat may reduce how effective it is.
Acarbose. This is used as a diabetes medicine.
Oral anticoagulants. Also known as blood thinners. Your GP or private clinician may want to monitor you if you take orlistat and an anticoagulant.
Amiodarone. Used to treat arrhythmias (abnormal heart rhythms).
For Mysimba, you may not be able to take the medicine if you’re on:
Monoamine oxidase inhibitors (MAOIs). These are a type of antidepressant.
Opioid analgesics. These are usually used to manage and treat moderate to severe pain.
CYP2B6 inducers, inhibitors, and substrates. These include medicines like carbamazepine, orphenadrine, and cyclophosphamide.
This isn’t an exhaustive list. Your GP or private provider can make sure whatever medication you’re taking is safe for you.
How to Increase the Effectiveness of Weight Loss Pills
No medication is a cure-all. Many weight loss pills are prescribed alongside a reduced-calorie diet and exercise as part of a wider treatment plan to help you lose weight.
Making changes to your eating and movement habits can not only make the medicine more effective, but it can also help you manage your weight and improve your health in the long run.
Here’s what to keep in mind on your weight loss journey.
Focus on Nutrition
Eat a healthy diet consisting mostly of whole foods.
Fruit, vegetables, nuts, seeds, whole grains, and legumes provide an array of vitamins, minerals, and antioxidants. They’re also high in fibre, which helps you feel full and avoid overeating.
Try to get your five a day, too. Fresh, canned, and frozen fruit and vegetables all count.
Lean protein — like chicken, turkey, tofu, and fish — can also help you feel fuller and build and maintain muscle, which can be lost when losing weight.
Move Your Body More
Regular physical activity can help promote weight loss, improve metabolism and heart health, and enhance the benefits of weight loss pills.
Aim for at least 150 minutes of moderate-intensity aerobic activity a week or 75 minutes of vigorous activity a week. That can include jogging, cycling, swimming, playing cricket, brisk walking, or taking heart-pumping gym classes.
As well as aerobic exercise, try to do at least two strength-training sessions a week. That can include bodyweight exercises, using dumbbells or resistance bands, or using machines in the gym.
Beyond planned training sessions, try to do more general movement throughout the day. Standing, walking, and stretching can all help.
Stay Hydrated
Drinking plenty of water can support a healthy metabolism, promote feelings of fullness, and aid in digestion. It’s also an opportunity to replace sugary beverages with plain water.
Keep a refillable water bottle with you. Sip from it regularly rather than trying to chug it all in one sitting. If you get bored of plain water, try sparkling water or add lemon wedges for some flavour.
Adjust Your Lifestyle Habits
Weight loss is personal. Think about how some of your everyday habits might be working against your weight loss goals.
For instance, can you improve your sleep quality or stress levels, stop smoking, or reduce your alcohol consumption? These can complement the effects of weight loss medications and contribute to better overall health.
Get Mental Health Support
Weight loss isn’t just physical. There’s often a deeper emotional and mental piece that needs to be addressed for success.
A counsellor trained in weight loss support and techniques like cognitive behavioural therapy (CBT) can help you address the emotional aspect and achieve long-term changes.
Beyond professionals, reach out to friends and family for support.
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What Is the Best Prescription Weight Loss Pill for You?
What prescription weight loss pills work best isn’t something we can answer for you personally. The option that works best will be not only effective but also safe and suitable for your unique needs.
Here’s what to bear in mind when considering prescription weight loss pills:
Effectiveness. Like all prescription drugs, a good prescription weight loss pill will have proven success in promoting weight loss in clinical trials. Pair it with lifestyle changes for long-term effectiveness.
Safety. Safety should be a top priority when choosing a weight loss pill. While any option will come with potential side effects, it’s vital to be aware of what they are and consider your risks.
Suitability. The best weight loss medication for you should align with your needs, including your goals, existing health problems, and lifestyle. Consulting a medical professional can help you figure out the most appropriate option.
To learn more about your options, you can take our free online weight loss assessment. A UK-licensed clinician trained in weight management can let you know if you’re eligible for weight loss medicine, including whether pills or injections could work best for you.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your GP about the risks and benefits of any treatment.