Which weight loss drug is right for you?
Robert Price | Last update: 29th October 2025
For those of you visiting SlimrChat for the first time to explore more about the prescription only GLP-1 weight loss drug treatments this is the start point for you.
In the UK the weight loss treatments that most people are using are Wegovy and Mounjaro. And they’re the ones that you’ll see across all the stories in the media. But what are they and how do they differ?
Here’s a simple, clear guide to help you understand what each treatment does, who they’re for, and what to expect. All so you can have an informed chat with your doctor or healthcare provider, which you must do before starting the treatments.
At a glance
- Wegovy contains semaglutide. This is a GLP-1 medication that helps control appetite and blood sugar.
- Mounjaro contains tirzepatide. This is a dual-action treatment that targets two hormones, GLP-1 and GIP.
- Nevolat / Saxenda contains liraglutide. This is an earlier-generation GLP-1 treatment taken daily rather than weekly.
- All are injections, with Mounjaro and Wegovy weekly and Nevolat daily. They can lead to significant weight loss and both should be used alongside healthy lifestyle changes.
What’s what
Wegovy
- Manufacturer: Novo Nordisk
- Active ingredient: Semaglutide
- How it works: mimics the natural GLP-1 hormone to help you feel full for longer, slow digestion and manage appetite.
- Approved for: weight loss and long-term weight management.
- Dose: 0.25 mg to 1.7 mg weekly using prefilled injection pen.
In short: Wegovy is the weight loss-specific version of semaglutide, designed and dosed for obesity treatment rather than diabetes.
Mounjaro
- Manufacturer: Eli Lilly
- Active ingredient: Tirzepatide
- How it works: targets two key hormones, GLP-1 and GIP. They help regulate blood sugar and appetite at the same time.
- Approved for: weight loss and long-term weight management.
- Dose: 2.5 mg to 15 mg weekly using prefilled injection pen.
In short: Mounjaro represents the start of the next generation of GLP-1-based treatments. Studies have shown it may deliver greater average weight loss than semaglutide in some people.
Nevolat
- Manufacturer: Zentiva
- Active ingredient: Liraglutide
- How it works: Acts on the GLP-1 hormone to slow digestion and help you feel satisfied sooner, supporting reduced calorie intake.
- Approved for: Weight loss and long-term weight management.
- Dose: 0.6mg to 3.o mg daily using prefilled injection pen.
In short: Nevolat is a once-daily GLP-1 treatment. It’s similar in action to Wegovy but requiring more frequent dosing. It’s an alternative to weekly injectables and can be a good option for people who prefer steady daily control or cannot access weekly pens.
How much weight will I lose?
Medication | Average Weight Loss (Clinical Trials) | Duration |
|---|---|---|
Wegovy (semaglutide) | Around 15 % of body weight | 68–72 weeks |
Mounjaro (tirzepatide) | Around 20–22 % of body weight | 72 weeks |
Nevolat/Saxenda (liraglutide) | Around 8–11 % of body weight | 56 weeks |
It’s important to remember that results vary. Some people lose more, others less. What matters most is finding the medication you can tolerate and sustain, along with lifestyle changes that feel realistic. These treatments should only be part of your weight loss journey.
Who can have the treatments?
Wegovy, Mounjaro and Nevolat are available privately and via the NHS weight loss schemes.
Here’s the current criteria for weight loss drug prescriptions:
- Over 18: these medications aren’t licensed for under-18s.
- NHS: To get weight loss drug on prescription from the NHS you need to have a body mass index (BMI) of at least 40 and at least 4 of the following 5 weight related conditions: type 2 diabetes, high blood pressure, heart disease, obstructive sleep apnoea, abnormal blood fats(dyslipidaemia). You must also agree to take part in additional lifestyle programmes to help your journey. Read more about getting the prescription and the NHS rules.
- Private prescriptions: Adults with a BMI of 30+, or 27+ with a weight-related condition (like type 2 diabetes, hypertension, or sleep apnoea).
- Commitment to healthy habits: diet, movement, and mindset support make the biggest difference.
Pricing
Private prices vary by pharmacy, dose and availability:
- Wegovy: lowest dose (0.25mg) us around £80 and highest dose (2.4mg) is around £200
- Mounjaro: lowest dose (2.5mg) starts at around £140 and highest dose (15mg) at £270
- Nevolat: starts at around £200 for 3 pens, which can last up to 34 days (depending on dose increases)
When are they not suitable?
These treatments aren’t usually prescribed if you:
- Are pregnant or breastfeeding
- Have a history of thyroid cancer (MTC) or MEN2
- Have severe gastrointestinal conditions such as gastroparesis
- Are allergic to any of the ingredients
- Are already taking another GLP-1 medication
Always discuss your full medical history with your doctor or healthcare provider. They’ll help decide what’s safe and appropriate for you.
What about side effects?
Most people experience some mild gastrointestinal side effects early on, which tend to ease as your body adjusts.
Common side effects include:
- Nausea or queasiness
- Constipation
- Fatigue
- Indigestion or reflux
- Feeling unusually full
Eating smaller portions, staying hydrated and avoiding greasy or heavy foods can help ease symptoms.
Many users say patience pays off. The first few weeks can be bumpy, but things usually settle by week four to six. Here’s our insight into side effects.
Wegovy vs Mounjaro vs Nevolat
Feature | Wegovy | Mounjaro | Nevolat/Saxenda |
|---|---|---|---|
Active ingredient | Semaglutide | Tirzepatide | Liraglutide |
Mechanism | GLP-1 only | Dual: GLP-1 + GIP | GLP-1 only |
Approved for | Weight loss | Weight loss | Weight loss |
Average weight loss | 15 % | 20 to 22 % | 8 to 11 % |
Dosing range | 0.25 to 1.7 mg weekly | 2.5 to 15 mg weekly | 0.6 to 3.0 mg daily |
Common Side effects | Nausea, constipation | Similar profile | Similar profile |
Frequency | Weekly injection | Weekly injection | Daily injection |
What’s best?
The “best” option depends on:
- Your health goals and medical history
- Advice from your doctor or healthcare provider
- How your body reacts to each treatment
- Cost and availability
- Your commitment to making long-term changes in diet, mindset and movement
Whatever you choose, consistency matters more than perfection and the SlimrChat community support can make all the difference.