Best weight loss injections in 2025
It can feel like there’s a lot of different weight loss injections available, like Wegovy, Mounjaro, and Saxenda.
They all have different active ingredients and results and that can make comparing them tricky – that’s why we’ve done a roundup of the best weight loss injections in the UK.
Weight loss injections are for people who are living with obesity and should never be used for cosmetic weight loss. At Oviva, we support eligible people experiencing obesity with prescription weight loss injections delivered to the door, plus a two-year personlised weight loss plan, all funded by the NHS.
What do weight loss injections need to work best?
Even the best weight loss injections need the right conditions to work. Clinical trial results are helpful, but don’t forget to factor in things like your lifestyle, support, and how well the treatment fits into your life:
Continued use
For the best results, weight loss injections need to be used regularly and as directed by your healthcare practitioner.
If you’re thinking about buying weight loss injections online, it’s important to bear in mind the cost in the long run. It can add up over time and make it difficult to keep up with treatment.
Explore the full cost of buying Wegovy online or buying Mounjaro online for one year.
The right dosage schedule
One of the reasons it’s so important to get weight loss injections under medical supervision is that a healthcare expert can give you a personlised dosing schedule.
How much to take and when to increase your dosage can only be properly assessed by a professional who can take your unique circumstances into account. It also means that if you experience any side effects, your healthcare practitioner can adjust your schedule to help.
And weight loss injection dosage schedules often differ. For example, Wegovy and Saxenda, have very different dosing requirements: you take Wegovy once weekly, whereas you take Saxenda once daily.
Lifestyle and habit changes
For weight loss injections to work best, they need to be combined with lifestyle changes like diet, exercise and sleep.
It’s not about making huge changes overnight. In fact, we often find that it has the opposite effect. Instead, it’s about building small, sustainable habits into your routine that you can stick to in the long term. That’s where we see the most lasting change.
That’s the backbone of the Oviva programme – it’s not about cutting calories or spending hours in the gym, it’s finding the changes that fit into your life. That could mean making two more meals from scratch each week, or going for a short walk on your lunch break.
UK’s best weight loss injections: weighing up your options
Take a look at the key similarities and differences between the UK’s best weight loss injections:
| Wegovy | Mounjaro | Saxenda | Ozempic | |
| Type of medication | GLP-1 agonist | GIP and GLP-1 agonist | GLP-1 agonist | GLP-1 agonist |
| Approved for | Weight loss | Type 2 diabetes and weight loss | Weight loss | Type 2 diabetes |
| Active ingredient | Semaglutide | Tirzepatide | Liraglutide | Semaglutide |
| Weight loss results (maintenance dose) | Up to 15.2% of body weight after 104 weeks | Up to 22.5% of body weight after 72 weeks | Up to 6.4% of body weight after 68 weeks | Up to 7% of body weight after 28 weeks |
| NHS availability | Available for weight loss as part of approved weight management services | Very limited availability for weight loss on the NHS Some availability for type 2 diabetes |
Available for weight loss as part of approved weight management services | Only available for type 2 diabetes |
| Typical private cost | £73.25 to £175.80 per pen
Each pen contains a 4-week supply |
£92 to £122 per pen
Each pen contains a 4-week supply |
£196.20 for five pens
Five pens contain a 4-week supply |
£73.25 per pen
Each pen contains a 4-week supply
|
| Typical maintenance dose | 2.4 mg/week | 15 mg/week | 3 mg/day | 1 mg/week
Can be raised to 2 mg/week if necessary |
| Dosage frequency | Once weekly | Once weekly | Once daily | Once weekly |
| Most common side effects | Nausea
Diarrhoea Vomiting Constipation |
Nausea
Diarrhoea Vomiting Constipation |
Nausea
Diarrhoea Vomiting Constipation |
Nausea Diarrhoea Vomiting Constipation |
What I love about Oviva is that I can eat what I want.
So, which is the best weight loss injection in the UK?
There’s no one-size-fits-all answer – the best weight loss injection is the one that works for you and allows you to make long-term lifestyle changes that help you keep weight off after stopping the medication.
Knowing which weight loss injection is best means taking into consideration things like dosage schedule, availability and side effects.
Daily vs. weekly
Weight loss medications can have different dosing instructions, which suit different people.
For example, some people prefer the routine of taking medication every day, like Saxenda, while others prefer taking it less frequently, like Wegovy’s weekly dosage schedule.
Which dosing schedule would suit you best?
NHS availability
Each injection has different availability on the NHS.
So, comparing Mounjaro and Wegovy, while Mounjaro achieved the best weight loss results in clinical tests, Wegovy is more readily available via the NHS.
And accessing weight loss injections through the NHS or an NHS partner is typically best. That’s because, not only does it help make it more affordable, but it also means you’ll get medical supervision throughout your treatment which is key to getting the most out of it safely.
Side effects
Side effects can vary from person to person, so the best weight loss injection for you may be different to someone else.
Wegovy, Saxenda and Ozempic are all GLP-1 agonists, meaning they target the GLP-1 hormone produced by the body after eating.
Mounjaro, on the other hand, is a dual agonist of GIP and GLP-1, targeting two hormones.
So, while the most common side effects for all four medications are similar, how they impact people can vary.
Each medication comes with its own contraindications too, which is why it’s so important to be medically assessed rather than buying online.
Access one of the UK’s best weight loss injections via the NHS
Oviva’s NHS-funded weight management programme includes:
- A tailored two-year weight loss plan
- Personalised, remote support from dietitians, doctors and more
- Weight loss medication delivered to your door (if eligible)
- Easy tracking of your meals, goals, mood and more through the Oviva app
Speak to your GP to find out if you’re eligible.
Everything you need for your appointment is in our handy info pack.
Never count calories again
Easily log your meals with the photo diary in the Oviva app – a simple way to keep track of what you’re eating.
Set goals that feel right
Your health coach will help you set the right personal goals that bring you closer to your feel-good weight.
Keep track of your progress
With your unique goals set, the Oviva app has all the tracking you need to work towards them with ease.
Become an expert yourself
With learning content on nutrition, exercise, and motivation, you’ll become a weight-loss expert yourself.
Always there to support
Get 1-to-1 support from a health coach and chat with our nutrition experts anytime via the Oviva app.
-
Weight management -
Type 2 diabetes -
Weight management