Retatrutide is still being researched, so it's not yet available for public use, but the study results look promising. You might be wondering whether you can combine it with other weight loss medications to boost your results even further. However, taking multiple weight loss injections together isn't recommended, and could actually be dangerous. Here's why combining these medications isn't a good idea.
What is retatrutide?
If approved, retatrutide would be the first "triple-agonist" weight loss injection, meaning it mimics three important hormones that control your metabolism:
- GLP-1 (helps you feel full and keeps blood sugar balanced)
- GIP (supports insulin release and helps your body process food for energy)
- Glucagon (tells your body to burn fat for energy)
This makes it different from Wegovy (which targets GLP-1) and Mounjaro (which targets GLP-1 and GIP). So far, retatrutide study results have been impressive. People taking the highest dose of retatrutide (12mg) lost over 24% of their body weight in 48 weeks, and 26% of participants lost at least 30% of their starting weight.
Compared to this, Mounjaro users lost around 21% and Wegovy users who lost 18% over the same time period (estimated from 72-week data). This suggests that retatrutide could become the most effective weight loss medication available—but it isn’t without side effects.
Can you combine different weight loss injections?
It's understandable why you might wonder if you can combine weight loss injections. Perhaps you've hit a plateau with your current treatment, or you're hoping to speed up your results by using multiple injections together. And when a new drug like retatrutide comes along, it can be tempting to try it even if your current medication is working well. However, combining weight loss injections is not recommended and could be dangerous.
Most weight loss medications, including Wegovy, Mounjaro, and retatrutide, act on similar hormone pathways. They all work to reduce your appetite, control blood sugar levels, and change how your body processes food and stores fat. So when you use them together, you're essentially doubling up on the same effects.
This can greatly increase your risk of severe side effects like nausea, vomiting, digestive problems, a dangerous drop in blood sugar (hypoglycemia), or dehydration. GLP-1 injections can also include serious, but less common, issues with your gallbladder or pancreas.
There's no evidence to show that combining weight loss injections will give you better results. Instead, you multiply the risks without proven additional benefits, so always stick to one prescribed treatment at a time. If you feel your progress has slowed or you’ve hit a plateau, speak to your provider so your dose and plan can be reviewed safely.
Can you take retatrutide with other weight loss injections?
Since retatrutide is still in clinical trials and not yet approved, you can't take it at all (whether alone or with other medications).
If retatrutide does become available in the future, it's highly unlikely doctors will recommend combining it with other weight loss injections like Wegovy or Mounjaro because it already works in the same way—and even more effectively. This means rather than maximising your results, you risk heightened side effects and a dangerous rate of weight loss.
Switching between weight loss injections
While taking two weight loss injections at once isn't recommended, you can switch your GLP-1 medication with proper medical guidance. If retatrutide becomes available and you think it might work better for you compared to Wegovy or Mounjaro, your clinician may discuss a switch.
There is no one-to-one dose between these medicines, and retatrutide is not approved, so there’s no switching guidance yet.
Any change will be individualised and based on the best available evidence, your current medicine and dose, your side effects and tolerance, and your goals. Clinicians typically avoid overlap and choose a cautious starting dose to limit side effects.
Wondering if weight loss medication could help you?
You shouldn't take retatrutide with other weight loss injections. Since retatrutide is still in clinical trials, it's not yet available anyway (we’ll probably have to wait until later next year). Even if it does get approved, combining it with other weight loss medications like Wegovy or Mounjaro would be dangerous.
If you’re curious about whether weight loss medicines could help you reach your health goals, or want to switch injections safely and effectively with guidance from a medical expert, Voy’s clinical team is here to help. Complete our quick eligibility quiz to find out whether you're eligible.
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