Jump to: Potential interactions between semaglutide and orlistat | Weight-loss with semaglutide and orlistat | Key considerations if taking Wegovy with orlistat | Take home message
There’s no published research investigating the impact of taking Wegovy or Ozempic (semaglutide) with orlistat.
However, it’s possible that you could take semaglutide (the drug in Wegovy and Ozempic) with orlistat as they support weight loss through different mechanisms.
Semaglutide works by mimicking the hormone GLP-1, which slows the rate of digestion and communicates with the brain’s appetite control centre, the hypothalamus, to lower hunger and food-seeking behaviour.
Semaglutide is a weight-loss injection taken once a week and is only available via prescription.
You can get a semaglutide prescription for weight loss on the NHS as part of specialist weight management services or privately. Second Nature provides Wegovy as part of our Wegovy weight-loss programme.
Orlistat, meanwhile, prevents up to one-third of the fat we eat from being absorbed through the gut and instead passes through the body in our stool.
Orlistat is available over the counter as orlistat or Alli and via prescription in higher doses as Xenical.
Still, there are possible interactions between these medications that could impact how the other drug works or increase the severity of the side effects you experience.
If you’re thinking about taking semaglutide with orlistat, we’d recommend speaking with your prescribing pharmacist or doctor before doing so.
Read on as we analyse the possible interactions between semaglutide and orlistat and what to consider when taking these drugs together.
1) Potential interactions between semaglutide and orlistat
As semaglutide and orlistat work through different mechanisms in the body, they may have a complementary effect on supporting weight loss.
However, as there’s no published evidence combining these drugs, it’s difficult to be sure how we might react when taking semaglutide and orlistat together.
Still, healthcare professionals may recommend taking these drugs together, at least for a short period, to help kickstart weight loss.
The main interactions to be aware of are the effects of both drugs on the gut and how this might affect its function.
Semaglutide mimics the hormone GLP-1. It activates GLP-1 receptors in the gut that slow down the rate of digestion.
The slower rate of digestion can lead to GI-related side effects like nausea, constipation, and vomiting.
In comparison, orlistat reduces the fat absorbed in the gut, which passes out in our stool. This can lead to oily stools and diarrhoea.
Generally, the side effects associated with these medications are mild, transient, and ease after the body adapts to the medication.
However, when used in combination, they might make us more susceptible to side effects that could impact quality of life.
Additionally, orlistat works by interacting with active sites in the gut that are responsible for aiding fat digestion.
It’s possible that taking semaglutide alongside orlistat may impact the action of orlistat in the gut. However, as no research has been conducted investigating this, we can’t say for sure whether it will have any effect whatsoever.
Key points:
- Semaglutide and orlistat have different mechanisms of action for weight loss: semaglutide slows digestion by mimicking GLP-1 (a fullness hormone), while orlistat reduces fat absorption in the gut
- No published evidence exists on combining these drugs, making outcomes and potential interactions uncertain, though healthcare professionals may recommend combination use to kickstart weight loss
- Both medications can cause gastrointestinal side effects: semaglutide may lead to nausea, constipation, and vomiting, while orlistat can cause oily stools and diarrhoea
- While side effects are generally mild and transient, combined use may increase susceptibility to these effects, potentially impacting quality of life
- The interaction between semaglutide and orlistat when used together is unclear, particularly regarding how semaglutide might affect orlistat’s action in the gut due to a lack of research on their combination
2) Weight loss with semaglutide and orlistat
Research has shown that semaglutide supports an average weight loss of around 15% after one year on the medication.
Orlistat, in comparison, supports an average weight loss of around 8% after one year. So, Wegovy is nearly twice as effective for weight loss than Orlistat.
Wegovy is a slow-acting medication that mimics one of our fullness hormones by communicating directly with the brain to lower hunger and food-seeking behaviours.
Wegovy directly influences our eating behaviour and lowers our desire to eat beyond our needs.
On the other hand, Orlistat has no direct impact on the brain or our appetite. It only works by reducing the amount of fat absorbed from food. Theoretically, you could over-compensate this action by consuming more calories from sugar or carbohydrates.
Would combining semaglutide and orlistat lead to more weight loss?
Theoretically, because semaglutide and orlistat have different mechanisms of action in the body, they may have a complementary effect and lead to more weight loss than when taken individually.
However, as no research has investigated the impact of these drugs in combination, we simply don’t know what the average weight loss will be.
Key points:
- On average, Wegovy supports weight loss of around 15% after one year, while orlistat supports around 8%
- Theoretically, combining the two medications could support more weight loss as they work differently in the body, but as no research has been conducted in this area we simply don’t know what the impact would be
3) Key considerations if taking Wegovy with orlistat
We’d recommend speaking with your doctor or prescribing pharmacist before taking Wegovy and orlistat together so they can continue to monitor your progress and vital blood markers.
Additionally, it’s essential to focus on developing healthy habits, like eating a balanced diet, exercising, and sleeping well when taking weight-loss medication.
Weight-loss medications can kickstart weight loss by lowering hunger or by lowering the number of calories you absorb through your gut.
However, they’re more effective when combined with a healthy lifestyle to ensure the body can still function effectively despite being in a calorie deficit.
Developing healthy habits will also improve your chances of maintaining weight loss in the long term if you decide to come off the medication in the future.
Finally, it’s worth being mindful of your fat intake while taking orlistat. As orlistat works by reducing the amount of fat absorbed in the gut, consuming high amounts of fat while on this medication may lead to worse side effects.
If you’re unsure of the best diet to eat while on weight-loss medication, you can follow Second Nature’s balanced plate model, which prioritises the intake of whole foods and limits the consumption of ultra-processed foods.
Following our balanced plate model will ensure you’re nourishing your body with everything it needs while eating in a way that is less likely to trigger adverse side effects of weight loss medication.
Key points:
- Speak with your doctor or pharmacist before combining Wegovy with orlistat
- Weight-loss medication is most effective when combined with healthy habits
- On orlistat, it’s recommended to be mindful of your fat intake. To strike the right balance, follow Second Nature’s balanced plate model.
Take home message
Due to their different actions on the body, combining Wegovy and orlistat may have a complementary impact on weight loss.
However, as research in this area is limited, we’d recommend speaking with your GP or prescribing pharmacist before taking these drugs in combination.
When taken individually, Wegovy will lead to more significant weight loss than orlistat with fewer side effects, so combining the two medications may not be necessary.
