¹Eli Lilly and Company. "Lilly's triple agonist, retatrutide, delivered weight loss of up to an average of 71.2 lbs along with substantial relief from osteoarthritis pain in first successful Phase 3 trial." Eli Lilly and Company, 11 Dec. 2025, https://investor.lilly.com/news-releases/news-release-details/lillys-triple-agonist-retatrutide-delivered-weight-loss-average.
They’re both weight loss injections that work by making you feel full. But retatrutide and Wegovy are quite different.
So, what sets them apart? Read on to find out.
Key Takeaways
- Retatrutide is not yet approved in the UK. Wegovy is available on the NHS and through private prescription
- Retatrutide targets three hormones (GLP-1, GIP, glucagon) compared to Wegovy's single hormone (GLP-1)
- Phase 3 trials show 28.7% average weight loss with retatrutide at 68 weeks versus approximately 20% with Wegovy 7.2mg at 68 weeks
- Side effects are similar for both, mainly digestive issues like nausea and diarrhoea
- Retatrutide approval is expected in mid to late 2026 at the earliest
Is retatrutide better than Wegovy?
First, a caveat: retatrutide isn’t approved yet, so nobody can’t prescribe it to you.
However, based on the data we have so far, retatrutide appears to be very effective for weight loss. The first phase 3 trial (TRIUMPH-4) showed an average weight loss of 28.7% at 68 weeks on the highest dose.
In comparison, Wegovy achieves approximately 20% weight loss at 68 weeks (20.7% at 72 weeks) for people taking a 7.2mg dose.
By the way: these results are from separate clinical trials, so we can’t really compare them directly. However, they can give us a sense of how well each medicine works.
Weight loss is a personal journey and there’s no single “best” medicine for it. There’s only what works for you. At Voy, our prescribers will work with you to create the perfect plan—whether that includes Wegovy weight loss injections or another medicine.
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Retatrutide vs Wegovy
Let’s take a closer look at how these two compare.
Features
Wegovy
Retatrutide
Active ingredient
Semaglutide
Retatrutide
Manufacturer
Novo Nordisk
Eli Lilly
Mechanism of action
Mimics the hormone GLP-1
Mimics GLP-1, GIP, and GCG
How it’s taken
Weekly injection
Weekly injection
Weight loss results after 68 weeks
Around 20% (7.2mg dose)
28.7%
Approved for use?
Yes. Available on NHS and via private prescription
No (expected 2026)
How is retatrutide different from Wegovy (semaglutide)?
The main thing that sets retatrutide and Wegovy apart is how they work.
Both mimic the effects of your body’s natural hormones to slow your digestion and keep cravings at bay.
But Wegovy only acts like one hormone, GLP-1. Whereas retatrutide mimics three: GLP-1, GIP, and GCG.
This triple action is why retatrutide is so potent. If you’d like to see how it stacks up against other GLP-1s, check out our guides on Retatrutide vs Mounjaro and Retatrutide vs Ozempic.
How fast can you lose weight on retatrutide and Wegovy?
Everyone’s different, so we can’t say for sure how fast you’ll see results. But people on either medicine might notice their appetite start to curb within the first few weeks.
Check your BMI today
Not sure where you stand? Calculate your BMI and find out what it means for you.
Wegovy vs retatrutide: side effects
Common symptoms are similar for both retatrutide and Wegovy:
- Nausea
- Diarrhoea
- Vomiting
- Constipation
This list isn’t exhaustive. Speak with your provider if you’re worried about side effects.
Side effects support at Voy
"If you're using Voy and you experience any side effects, rest assured that our expert clinicians are just a message or phone call away. They can adjust your dose, prescribe medication to ease your symptoms, or simply offer reassurance.
Everyone responds differently to weight loss treatment and we'll help you find what feels right for you."
Wegovy vs retatrutide: cost
We don’t know how much retatrutide will cost until it launches. But it will probably be priced similarly to Wegovy and Mounjaro weight loss injections. Prices can vary between private providers.
Whatever you do, make sure you’re buying from a registered provider. Otherwise, there’s no guarantee the products are genuine or safe to take.
How can you get Wegovy and retatrutide in the UK?
Retatrutide isn’t available on the NHS or in the UK because it isn’t approved yet.
Wegovy is available on the NHS. But for now it’s limited to people who meet strict criteria and whose GP is part of the rollout.
If you don’t meet NHS criteria or want to explore treatment sooner, you may already be eligible through a private prescription—including through our weight loss treatment. We’ll post you monthly weight loss medication and help you to transform your lifestyle, so you keep the weight off for good.
By the way: as well as Wegovy and other approved weight loss injections, we’ve got orlistat weight loss capsules, too.
Our Voy weight loss results speak for themselves: 94% say it’s the best weight loss treatment they’ve tried. Take our quiz to see if you’re eligible.
