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Wegovy vs Orlistat

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

7 min read
Last updated February 2024

Jump to: How do Wegovy and Orlistat work? | Do you lose more weight on Wegovy or Orlistat? | Wegovy vs Orlistat: Which should I choose for weight loss? | Take home message

Wegovy is generally a more effective weight-loss medication than Orlistat. Research has shown that Wegovy can lead to weight loss of 15-20%, whilst Orlistat may lead to weight loss of 4-8%.

This research suggests that Wegovy leads to at least 10% more weight loss than Orlistat over the course of a year.

So, if you’re looking for a weight-loss medication and need to lose weight, Wegovy would likely be the most effective option.

However, everyone responds differently to medications, and you might not respond well to Wegovy. In this case, Orlistat might be a better option for you; it’s also cheaper than Wegovy.

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Wegovy’s not a magic pill

Wegovy is designed as an additional tool for weight management and, in most cases, shouldn’t be considered a lifelong medication.

Instead, it should be used to help you kickstart your weight loss journey whilst you commit to living a healthier lifestyle.

Ideally, we’d be able to lose weight without medication and lifestyle changes would be enough to support weight loss in the long term.

We’d generally recommend trying Second Nature’s weight-loss programme before considering a weight-loss jab.

Changing your habits is the most sustainable way to achieve long-term weight loss, and it’s also less expensive.

At Second Nature, we’ve been trusted by the NHS since 2017 to support people with type 2 diabetes and obesity to lose weight, manage their blood sugar levels, and lead healthier lifestyles for the long term.

In 2022, the NHS published data in the BMJ that compared the weight loss outcomes of five providers in the National Diabetes Prevention Programme.

Second Nature was more than twice as effective at supporting weight loss than the other four providers.

However, if you’ve decided to try Wegovy but need support in making positive changes to your lifestyle, Second Nature could be an option for you. But it’s worth noting that we have strict eligibility criteria.

Otherwise, keep reading as we examine the key differences between Wegovy and Orlistat.

1) How do Wegovy and Orlistat work?

Wegovy and Orlistat are weight-loss medications approved for use in the UK. However, they are different medications with distinct dosing schedules, costs, and mechanisms of action on the body.

Orlistat is a lipase inhibitor. Lipases are gut enzymes that break down fat from food, enabling the gut to transport fat into the body to be burnt for energy or stored in our fat cells for later use.

Orlistat blocks lipases, preventing some of the dietary fat from our meals from being digested. This leads to fewer calories being absorbed, which can support weight loss.

Orlistat is a prescription medication produced by two pharmaceutical companies in the UK:

  1. GlaxoSmithKline: Alli, 60 mg and available over the counter (no prescription)
  2. Roche: Xenical, 120 mg and available with a prescription

Wegovy is a weight-loss jab manufactured by Novo Nordisk. It’s a weekly weight-loss injection with semaglutide as the active ingredient.

Semaglutide is a GLP-1 receptor agonist that helps reduce hunger and appetite by mimicking the fullness hormone GLP-1, allowing you to eat fewer calories, lose weight, and manage your blood sugar levels.

Wegovy is approved in the UK for individuals living with obesity to help them eat fewer calories and lose weight.

Key points:

  • Wegovy is a weight-loss injection and semaglutide is the active ingredient
  • Semaglutide is injected weekly and mimics the fullness hormone GLP-1 to lower hunger and support weight loss. You need a prescription to get Wegovy for weight loss.
  • Orlistat is a weight loss pill and orlistat is the active ingredient.
  • Orlistat is also sold under the brand names Alli and Xenical. Alli is available over the counter, while Xenical requires a prescription.
  • Orlistat is a lipase inhibitor. Lipases are gut enzymes that break down fat in your gut. By blocking lipase, you absorb fewer calories from your food.

2) Do you lose more weight on Wegovy or Orlistat?

Wegovy supports more significant weight loss than Orlistat. Randomised controlled trials have shown that Wegovy, alongside a lifestyle intervention, leads to 15-20% weight loss after one year.

In comparison, research shows that Orlistat supports 4-8% weight loss, suggesting that, on average, Wegovy leads to at least 10% more weight loss than Orlistat over a year.

Why is Wegovy more effective than Orlistat?

One factor is the advances in our research and development. As time progresses, research teams find new ways to help our bodies function better and help combat chronic diseases.

Orlistat is an older medication approved for weight loss in 2007 in the UK. Wegovy, in comparison, was only approved for weight loss in 2023 in the UK.

Our understanding of the body has advanced significantly since 2007, and Novo Nordisk’s researchers have produced a compound that’s more effective at weight loss than Orlistat.

Another factor is the way the two drugs work. 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.

Key points:

  • Wegovy supports more significant weight loss than Orlistat. On average, Wegovy will lead to 10% more weight loss than Orlistat.
  • Wegovy’s effectiveness is likely down to recent innovations in pharmacotherapy and how it communicates with the brain

3) Wegovy vs Orlistat: Which should I choose for weight loss?


Wegovy is generally a more effective medication. On average, it leads to at least 10% more weight loss than Orlistat.


Wegovy is more expensive than Orlistat. With Second Nature, one month’s prescription of Wegovy with the injectable pen required will start at £229 at the lower doses, rising to £299 on the higher doses.

This cost includes access to our app, smart weighing scales, and support from a registered dietitian or nutritionist five days a week.

Orlistat starts as low as £18 a month for the over-the-counter version, rising to around £40 monthly for the prescription.

Orlistat is a much more economical option as a weight-loss medication. So, if you need support to lose weight and can’t afford Wegovy, Orlistat could be a good option for you.

Orlistat is available from registered online retailers and pharmacies.

Side effects and safety

Orlistat has a slightly better safety profile than Wegovy.

A clinical trial on Orlistat with 237 participants reported that 56% of individuals reported side effects, with 59.2% being GI issues such as bloating, cramping, and diarrhoea.

Still, only 8.5% of individuals discontinued the use of orlistat due to these side effects, and only two serious adverse events were reported as being associated with the medication.

In comparison, research on Wegovy has shown that around 80% of participants report side effects, with 13.5% discontinuing the medication due to the adverse effects.

So, around 30% more people experience side effects on Wegovy than Orlistat, and 5% more stop taking the medication due to the adverse events.

Key points:

  • Wegovy is a more effective weight-loss medication
  • Wegovy is more expensive than Orlistat and has a slightly worse safety profile
  • But, both medications are generally well-tolerated
  • Whether you choose Wegovy or Orlistat will depend on many factors, such as affordability and your response to the medications

Take home message

The recent innovations in GLP-1 medications are pretty remarkable and have caused quite a stir in the world of healthcare.

We’re in new territory where obesity and type 2 diabetes medications treat an underlying cause instead of merely treating the symptoms to support better management.

However, these drugs shouldn’t be seen as miracle cures; they’re not designed to be used for life.

They’ve been designed to be taken alongside lifestyle changes that will enable you to eventually come off the medications and maintain your lower weight for the long term.

GLP-1s are safe and effective for most people in the short to medium term, but we don’t have long-term data to be sure they’re not causing severe adverse effects elsewhere.

At Second Nature, we’re not against using medications to support people in making healthy changes and reducing their risk of chronic disease.

However, we don’t recommend using medications as a reason not to make healthy lifestyle changes. The causes of obesity and type 2 diabetes aren’t merely rooted in biology but also in psychology and sociology.

With these medications, you may lose weight and reduce blood sugar levels. But will you be happier? Will you be more fulfilled? Will you be content with your life and social relationships?

For that, you may need to consider a lifestyle change, and if that’s something you want to commit to alongside taking GLP-1 medications, then give Second Nature a try.

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