The ultimate guide to medical weight loss: How prescription treatments can help you lose weight safely

A safe, effective weight loss programme requires more than just diet and exercise. You also need the right guidance and support to lose weight consistently and keep it off for good.

Medical weight loss combines natural weight loss strategies like healthy eating, regular exercise and getting plenty of sleep with expert support from a medical professional. By including prescription medications like regulated slimming pills and weight loss injections, you can enhance your results and enjoy a healthier lifestyle.

At The Online Clinic, you can find a UK-registered online doctor to help you on your journey with a suitable prescription weight loss treatment. We prioritise patient safety and take steps to ensure we prescribe medications that are right for you.

Register online to join our medical weight loss clinic and arrange specialist support today.

How do prescription weight loss treatments work?

Weight gain is influenced by a number of factors. Some people feel constantly hungry, whereas others might be genetically predisposed to storing more fat or burning less.

Depending on your personal relationship with weight, an online doctor for weight loss might prescribe medications that:

• Reduce your appetite: Semaglutide weight loss injections like Wegovy tell your brain you're full and reduce feelings of hunger
• Increase feelings of fullness: Liraglutide weight loss injections like Saxenda slow digestion, helping you feel fuller and lowering your drive to eat
• Reduce fat absorption: Weight loss pills containing orlistat decrease the amount of fat your body absorbs from food
• Improve metabolic regulation: Some medical weight loss treatments increase your energy expenditure and promote fat burning, even at rest
• Boost insulin sensitivity: Many treatments are designed to help those with type 2 diabetes by restoring insulin sensitivity

Not every prescription weight loss treatment is suitable for all people.

That's why you should always consult a doctor before using any weight loss medication. Medical weight loss is a safe way to lose weight and improve your wellbeing, but only with specialist supervision.

Types of prescription weight loss medication

GLP-1 receptor agonists

Examples: Wegovy, Mounjaro and Saxenda

Most GLP-1 receptor agonists help manage blood sugar levels in people with type 2 diabetes. But some can also be used as part of a medical weight loss programme. While some are in pill form, most come as weight loss injections.

GLP-1 is a hormone that your body releases when you eat. It:

• Triggers insulin release
• Blocks the secretion of glucagon (a hormone that increases blood sugar levels)
• Slows digestion
• Increases feelings of satiety

GLP-1 agonist medications mimic this hormone, giving you all the benefits even without a big meal. The combined effects of reduced appetite, slower digestion and lower blood sugar spikes often result in weight loss.

Wegovy

Is Wegovy effective?

Wegovy (semaglutide) is shown to be highly effective in clinical trials. Patients with a body mass index (BMI) of over 30 lost an average of 15% of their body weight over two years. Those in the placebo control group lost just 2.4%.

Common side effects of Wegovy

• Headaches
• Nausea or vomiting
• Fatigue
• Diarrhoea

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Mounjaro

Is Mounjaro effective?

Mounjaro is one of the main weight loss injections currently prescribed in the UK due to its significantly higher success rate. Over a 72-week period, clinic trial data showed an average weight loss of over 20% in those taking higher doses. In the placebo control group, weight loss was just 2.4%.

Common side effects of Mounjaro

Common side effects include vomiting, constipation and diarrhoea, though these tend to disappear quickly. People also report low blood pressure, excess gas, fatigue and hair loss. People with type two diabetes who are also using a medicine containing sulphonylurea or insulin could experience hypoglycemia.

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Saxenda

Is Saxenda effective?

Clinical trials show that Saxenda (liraglutide) is an effective and safe weight loss treatment. Around 65% of patients achieve meaningful weight loss.

Common side effects of Saxenda

Most people tolerate Saxenda remarkably well, with no side effects at all. A small number of people report:

• Slight nausea
• Indigestion
• Diarrhoea

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Lipase inhibitors

Examples: Orlistat, Xenical and Alli

During digestion, enzymes called lipases break down fats into smaller molecules so your intestines can absorb them.

Lipase inhibitors bind to those enzymes to prevent them from interacting with fats. This reduces the amount of fat you absorb. Instead of being digested, it passes out of your body in your poo.

Fat is the most calorie dense macronutrient. By limiting the amount of fat you absorb, lipase inhibitors also decrease the number of calories you take in. This keeps you from gaining additional weight and can lead to weight loss.

Orlistat

Is orlistat effective?

Studies have shown that using orlistat alongside a weight-reducing diet and exercise can help patients lose 10% or more of their body weight within six months.

Common side effects of orlistat

Very few people experience side effects while taking orlistat. The most common side effects are gastrointestinal such as nausea, diarrhoea, constipation and flatulence. These can be lessened with dietary changes.

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Xenical

Is Xenical effective?

In clinical trials involving two groups on the same low-calorie diet, the group taking Xenical lost around twice as much weight as those on the diet alone.

Common side effects of Xenical

Not everyone experiences side effects from taking Xenical. But as a brand-name version of orlistat, it can also cause some gastrointestinal side effects such as constipation, diarrhoea and flatulence.

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Alli

Is Alli effective?

GlaxoSmithKline, the manufacturers of Alli, say that the drug can reduce dietary fat absorption by up to 25%. In clinical trials, patients lost up to 50% more weight when taking Alli compared to simply dieting.

Common side effects of Alli

Alli is made from the same drug as Xenical, but is administered at a lower dose. As such, they share the same common side effects. Though these are less likely when taking Alli due to the lower amount of orlistat.

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Sympathomimetic appetite suppressants

Examples: Mysimba

Your hunger and appetite are controlled by the interaction of chemicals throughout your body and brain. These include:

• Hormones (e.g. ghrelin, leptin, insulin, cortisol)
• Neurotransmitters (e.g. GABA, serotonin)
• Peptides (e.g. GLP-1)

Different sympathomimetic appetite suppressants block or increase specific chemicals. This makes you feel less hungry, or fuller faster when you eat.

By reducing the amount of food you want to eat, these weight loss medications reduce your calorie intake. This helps you create a calorie deficit, which leads to weight loss.

Mysimba

Is Mysimba effective?

Data from Phase 3 clinical trials shows that 50.7% of Mysimba users lost over 5% of their body weight within 16 weeks. 55% of those lost more than 10% of their body weight after one year.

Common side effects of Mysimba

Most patients don't experience any side effects while taking Mysimba. Those who do have reported:

• Anxiety
• Insomnia
• Headache
• Restlessness
• Dizziness
• Reduced concentration
• Palpitations
• Hot flushes
• Nausea
• Constipation
• Muscular pain

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Comparing weight loss medications

Who qualifies for medical weight loss?

In the UK, most people over the age of 18 can qualify for prescription weight loss treatment if they have:

• A BMI of over 30
• A BMI of over 27 and a weight-related condition such as high blood pressure, type 2 diabetes or sleep apnoea

You can check your BMI using our handy online BMI calculator.

However, your doctor will only prescribe weight loss medication if diet and exercise alone haven't helped you lose weight, and your weight is a health risk.

Medical weight loss treatments also aren't usually recommended for:

• Pregnant or breastfeeding women
• Adults over 75 years old
• Those with certain health conditions, like liver or kidney problems

Potential risks of weight loss medications

The potential risks and side effects of medical weight loss treatments differ depending on the drug, your health conditions and how your body reacts.

Common side effects of weight loss drugs include:

• Gastrointestinal issues (nausea, vomiting, constipation, diarrhoea, heartburn)
• Increased risk of gallbladder disease
• Increased risk of fracture
• Possible pancreatitis

However, a recent study published in the journal Nature Medicine showed that GLP-1 agonist medications may actually protect against 42 other diseases. This includes reduced risk of:

• Liver failure (24%)
• Cardiac arrest (22%)
• Alzheimer's disease (12%)
• Heart failure (11%)
• Heart attack (9%)
• Ischaemic stroke (9%)

That said, the same study also noted an increased likelihood of 19 side effects or diseases, including a higher risk of:

• Drug-induced acute pancreatitis (2.5 times more likely)
• Nausea or vomiting (30%)
• Arthritis (11%)
• Low blood pressure (6%)

While these results aren't conclusive, it's true that using weight loss medication can result in some unwanted risks and side effects. That's why your doctor will only prescribe a medical weight loss programme if the benefits greatly outweigh the risks.

Potential contraindications of weight loss medications

A contraindication is when introducing a new medication or treatment could react poorly with an existing condition or prescription. This is why it's so important for your doctor to carry out a thorough review of your medical history before prescribing weight loss medication.

Different medical weight loss treatments can have different contraindications. But general contraindications across all weight loss medications include:

• Pregnancy and breastfeeding: Taking weight loss medication during pregnancy can result in excessive, unhealthy weight loss. And some medications such as phentermine are associated with foetal stroke. While it's unknown whether weight loss medication is excreted in breast milk, rapid weight loss is known to negatively impact milk production
• Eating disorders: Little research has been conducted into the relationship between weight loss medications and eating disorders like anorexia or bulimia. But the associated drive for thinness could present a risk of misuse, malnourishment, and worsening cognitive and behavioural symptoms of eating
• Allergies: Severe allergic reactions to weight loss medications, such as anaphylaxis, are rare, but still possible
• Children or adolescents: Most prescription weight loss medications are licensed for adults only. In rare cases, some can be prescribed for weight management in children over the age of 12

These potential risks and contraindications are why it's so important to work with a registered and trusted medical provider for prescription weight loss treatment.

When you register with The Online Clinic, we ask you to complete a short medical questionnaire to confirm that weight loss medication is right for you. Our doctors perform a thorough check of your medical history to ensure you face the lowest possible risk.

How to reduce the risks of prescription weight loss treatment

Use a UK-registered provider: There are a lot of fake weight loss medications on the market, and they might not be what they say they are. Getting authentic medication from a UK-registered provider ensures you get the correct dosage

• Be honest with your doctor: Provide accurate information about your height, weight and medical history. That way, your doctor can prescribe a medication that's suitable for you
• Get proper medical supervision: Only use medical weight loss treatments under medical supervision. This ensures your meds are right for your health profile, and that side effects are monitored and managed early on
• Take meds as prescribed: Don't skip doses or double up. Only use your medication exactly as prescribed
• Avoid alcohol and recreational drugs: Some weight loss medications react poorly with alcohol and drugs, which could cause serious long-term harm
• Track your symptoms: Use a notes app or journal to monitor side effects, mood changes and appetite patterns. Share this with your doctor so it can help guide better decisions for your weight and health

Prescription treatments vs lifestyle-based weight loss

It's important to understand that prescription weight loss medications don't replace diet and exercise.

Instead, they should be used as one part of a broader weight loss programme to kick-start your weight loss and improve your results.

Failing to maintain a proper diet and exercise routine could prevent your prescription weight loss treatment from having a significant effect. And you could even continue to gain weight.

To lose 0.5-1kg (1-2 lbs) a week, a person must reduce their dietary intake by 500 calories per day. You can achieve this by eating a balanced diet with plenty of vegetables and fruits, high-fibre foods, beans and pulses, lean protein, oily fish and small amounts of unsaturated oils.

The NHS physical activity guidelines for adults aged 19 to 64 also recommend:

• Strengthening activities that work all major muscle groups on at least two days a week
• At least 150 minutes of moderate-intensity activity a week, or 75 minutes of vigorous-intensity activity a week
• Reducing time spent sitting or lying down, and breaking up long periods of not moving with some activity

If you're struggling with these recommendations, remember that even small dietary changes and 10 minutes of activity a day is better than nothing. It's okay to introduce better food choices and more exercise slowly, and build up as part of your weight management routine.

A supervised medical weight loss programme is a great way to start your weight loss journey. These medications enhance weight loss, making it easier to move more and make better choices.

By combining natural lifestyle changes with a suitable prescription weight loss treatment, you can take the first steps to a healthier, happier you.

Common myths and misconceptions about medical weight loss

“I don't need to diet or exercise”

Weight loss medication supports healthy eating and exercise. Without lifestyle changes, your treatment won't have a long-term effect.

“I'll lose lots of weight quickly”

Most people lose around 5-10% of their body weight over several months, not instantly. Weight loss is gradual and relies on consistent treatment and lifestyle changes.

“Weight loss meds are only for lazy people”

Overweight and obesity are caused by many factors, including your genetics, hormones, psychology and socioeconomic situation. Medication is just another tool in a comprehensive weight loss programme. It's not a sign of failure or weakness – it's a smart choice.

“I can take these meds forever”

Most weight loss medication is meant for short- to medium-term use under medical supervision. Stopping treatment without lifestyle changes often leads to regaining lost weight.

“I'll lose the same weight as everyone else”

Everyone responds differently to weight loss medication. How much you lose will depend on your starting BMI, underlying health conditions, adherence to lifestyle changes, and side effects.

How to access safe and effective prescription weight loss

If diet and exercise haven't helped you lose weight, you might decide to try a prescription weight loss treatment.

One option is to schedule an appointment with your GP to get a prescription for weight loss medication. But it can often take several weeks just to get an appointment, and much longer for your treatment to be approved and prescribed.

That's why thousands of people across the UK prefer to use an UK-registered online doctor for weight loss treatment.

When you schedule an appointment with an online medical weight loss clinic, you enjoy:

• Fast diagnosis: Independent online doctors for weight loss don't have the same enormous patient load that slows down the NHS. So you can get your prescription weight loss treatment much more quickly
• Easy accessibility: You can order the prescriptions you need from the comfort of your own home. This is particularly important for those who have a chronic condition or mobility issue, live in a remote area or face transport challenges
• Total discretion: Some people see living with being overweight as a source of shame or embarrassment. A licensed online doctor service doesn't require you to attend an in-person consultation.
• Comprehensive guidance: Leading online pharmacies provide an extensive database of medical information. So you can conveniently access information about prescribed medications online and make informed decisions about your healthcare
• Secure prescription processing: Using a trusted online pharmacy or doctor service ensures security and compliance. We follow stringent regulations and use secure systems to handle your data and ensure confidentiality

Why choose The Online Clinic for medical weight loss?

Hundreds of thousands of patients rely on The Online Clinic for digital consultations and treatments covering dozens of medical conditions, including medical weight loss.

With more than 20 years' experience and 13 UK-registered doctors, we're one of the most well-established online healthcare providers in the country. Our clinic is licensed by the Care Quality Commission (CQC) to ensure patient satisfaction. And we carry a CQC rating of Good in all five assessed areas, which means “the service is performing well and meeting expectations”.

Using our convenient doctor-patient interface, you can access safe medical weight loss treatments from the comfort of your own home. All you need to do is follow these five simple steps:

• Consultation: Complete our registration form and medical health questionnaire, which takes just a few minutes
• Diagnosis: One of our registered doctors will review your submission and initiate an online consultation with you. We handle most consultations in just 30-60 minutes during normal business hours
• Purchase your prescription: After diagnosis, you can access any medications your doctor approves for purchase
• Repeat prescriptions: You can log in at view approved medications at any time to select medications for repeat purchase
• Delivery: If you order by 3:30pm Monday to Friday (public holidays excluded), your medication will be dispatched on the same business day for next day delivery. All medication arrives discreetly packaged

Great for weight loss meds Having tried to register for a weight loss prescription with online pharmacies, The Online Clinic is far easier, faster and, overall, more satisfactory. The others providers had quite stressful processes when compared to The Online Clinic, where their approach was more integrated. Obviously, it is important to be cautious when prescribing medications but I felt the other websites were difficult to navigate and upload required information. The Online Clinic was a breeze by comparison – they have clearly put a lot of thought into their systems to make them easy for patients to use, which still requires the same information (like photos and ID). There are also other private providers who utilise pharmacists and not qualified doctors to do the initial consultation. I feel better having a consultation directly with a doctor, which I got from the Online Clinic. The delivery of the medication has been really quick and the pricing is competitive with the lowest prices on the market at the moment. Just make sure to use the discount code for the repeat prescriptions. I have already recommended The Online Clinic to my work colleagues and will continue to do so. Paul

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Book your medical weight loss consultation today

Register online and complete your medical health questionnaire in just a few minutes to start your weight loss journey with professional medical support.

Medical weight loss frequently asked questions

Are prescription weight loss medications safe?

Yes, they are. Weight loss injections and pills available for prescription in the UK have been approved by the UK regulatory body (MHRA) based on thorough research.

While every medication has risks, they're only prescribed when the benefits outweigh those risks.

What are the benefits of a medical weight loss programme?

When you begin a medical weight loss programme, you benefit from:

• Personalised, evidence-based treatment
• Supervision from a medical professional
• Better long-term weight loss and lifestyle changes
• Improvements in many chronic conditions
• Improved energy, mobility and mental health
• Increased confidence and quality of life

Will I suffer bad side effects from weight loss medication?

Some people experience nausea, digestive issues or other problems. But these lessen over time, and most people tolerate weight loss injections and pills very well.

Serious side effects are rare. And we provide continuous monitoring to help keep you safe.

Will I regain weight if I stop taking them?

If you return to unhealthy habits, you could gain the weight back. But weight loss medication helps you create momentum for long-term lifestyle changes. They give you the space and confidence to make positive lifelong improvements.

Will weight loss medications affect my mental health?

Your doctor will thoroughly screen your mental health history before prescribing weight loss medication. This reduces the risk of negative mental health effects.

Useful resources for a successful weight loss journey

National Health Service

• Weight loss guidelines
• Obesity treatment
• Eating a balanced diet
• Exercise

Mayo Clinic

• Prescription weight-loss drugs
• Fitness basics

National Institute of Diabetes and Digestive and Kidney Diseases

• Prescription medications to treat overweight and obesity
• Tips for starting physical activity