Second Nature logo



Wegovy vs Mounjaro

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

8 min read
Last updated May 2024

Jump to: What are Mounjaro and Wegovy? | Mounjaro and Wegovy dosing schedulesHow do Wegovy and Mounjaro work? | Mounjaro and Wegovy for weight loss and type 2 diabetes | Mounjaro vs. Wegovy: Which one should I choose? | Take home message

The two most popular weight-loss injections available to buy privately in the UK are Wegovy and Mounjaro.

Wegovy is manufactured by Novo Nordisk, while Mounjaro is by Eli Lilly. The drug in Mounjaro is called tirzepatide, and in Wegovy it’s called semaglutide.

Research suggests that Mounjaro leads to more weight loss than Wegovy, with Mounjaro supporting an average weight loss of around 25% after one year, compared to 16% while on Wegovy.

However, it’s important to note that responses to medications vary between individuals.

Second Nature has launched both a Wegovy weight-loss programme and a Mounjaro weight-loss programme, with all doses in stock for both medications.

Check my eligibility

What are Mounjaro and Wegovy?

Mounjaro and Wegovy contain drugs that mimic two hormones in the body that lower hunger: GLP-1 and GIP.

The GLP-1 hormone has three major effects in your body:

1 – It slows the rate of food movement from your stomach to your small intestine
2 – It communicates with the appetite control centre in your brain to increase satiety so you feel less hungry
3 – It manages the release of the insulin and glucagon hormones in your body, ultimately leading to lower blood sugar levels (generally a good thing)

The natural GLP-1 hormone in your body lasts only a few minutes, whereas the GLP-1 drugs can last for many days. This means they can have the above effects over a more sustained period.

All-in-all, this leads to people feeling less hungry because they have food in their stomachs for longer, and GLP-1’s effect on the brain means that people feel like they have less ‘food noise’ and reduced desires for highly-desirable foods.

The main difference between Wegovy and Mounjaro is that the drug in Wegovy mimics a single hormone, GLP-1, while the drug in Mounjaro mimics both GLP-1 and GIP.

GIP is a hormone that supports blood sugar levels and helps our fat cells store more excess energy we might consume in our diets.

It’s thought this dual-action effect of Mounjaro is why better weight-loss results have been seen in the clinical trials published so far.

Mounjaro and Wegovy dosing schedules

The other major difference between Wegovy and Mounjaro is the dosing schedules.

Wegovy has been approved to be delivered at its maximum 2.4 mg dose, which is called its ‘maintenance’ dose.

To reach the maintenance dose level of 2.4 mg, there are four ‘escalation’ doses that you must take over four months to reach the maximum 2.4 mg dose.

It looks like this:

Wegovy dosing schedule

The clinical licensing for Wegovy is clear that it’s mandatory to increase doses each month until the maximum 2.4 mg maintenance dose has been reached.

Mounjaro is slightly different because it has 3 different maintenance doses: 5 mg, 10 mg, and 15 mg.

What this means is that there’s currently more flexibility with the dosing schedules of Mounjaro over Wegovy.

If people feel that they are getting good weight-loss results at a lower maintenance dose of Mounjaro (e.g. 5 mg or 10 mg) then they don’t need to increase their dose further.

Mounjaro also has ‘escalation’ doses, which you’ll be required to take for four weeks if you decide to move up from one maintenance dose to another.

For example, if your current maintenance dose is 5 mg and you want to move up to a 10mg maintenance dose, then you’ll need to spend 4 weeks on the 7.5 mg escalation dose.

If you wanted to go straight up to the maximum 15 mg dose of Mounjaro, this is what your titration plan would look like:

Mounjaro dosing schedule

1) How do Wegovy and Mounjaro work?

When we eat food, our gut releases hormones that help the body regulate hunger and blood sugar levels. One of these hormones is GLP-1.

GLP-1 improves insulin function to lower blood sugar levels and delay gastric emptying, decreasing appetite.

GLP-1 also communicates with the brain’s appetite control centre, the hypothalamus, to lower food-seeking behaviour.

How Wegovy mimics GLP-1 to support weight loss

Another hormone released from the gut is GIP. GIP helps regulate blood sugar levels and helps our fat cells ‘absorb’ more energy from the bloodstream, which prevents fat from being stored in the liver or pancreas.

GIP also communicates with the brain and is believed to have a similar role to GLP-1 in lowering hunger.

So, both GLP-1 and GIP are hormones released in response to food and signal to the brain to lower hunger and food-seeking behaviours.

How Mounjaro mimics GIP to promote weight loss

However, both hormones are removed from our blood quickly after being released. For example, after two minutes, 50% of the GLP-1 released from the gut in response to a meal is removed from the blood.

This short lifespan means that the effects of GLP-1 and GIP to lower hunger are often short-lived.

How Wegovy works

Wegovy is known as a GLP-1 receptor agonist as it mimics the actions of the hormone GLP-1.

The active ingredient in Wegovy is semaglutide. Semaglutide is about half as potent as the real GLP-1 hormone produced in the gut.

However, semaglutide has been developed to last longer in the blood to provide a sustained effect of lowering hunger to help people eat less and lose weight.

After 4-5 weeks on Wegovy, the semaglutide in the blood reaches a level known as its ‘steady state’. This means its levels will be consistent and stable rather than rising and falling.

How Mounjaro works

Mounjaro is also known as a GLP-1 receptor activator, as it mimics the actions of the hormone GLP-1.

The active ingredient in Mounjaro is tirzepatide. Tirzepatide is about a quarter as potent as the GLP-1 hormone produced by the gut.

However, tirzepatide has the additional function of mimicking the hormone GIP. Because of this additional action, Mounjaro is known as a dual-action GLP-1 and GIP receptor agonist.

Like Wegovy, Mounjaro is a long-acting medication. It takes 4-5 weeks for its active ingredient, tirzepatide, to reach a level in the blood we call its ‘steady state’ where its levels remain consistent and stable in the blood.

Key points:

  • GLP-1 and GIP are hormones released by the body after we eat food
  • They communicate directly with the brain to lower hunger and food-seeking behaviours
  • Wegovy is a single-action weight-loss injection and mimics the actions of the GLP-1 hormone
  • Wegovy’s active ingredient is semaglutide and is manufactured by Novo Nordisk
  • Mounjaro is a dual-action weight-loss injection and mimics the actions of the hormones GLP-1 and GIP
  • Mounjaro’s active ingredient is tirzepatide, and it’s manufactured by Eli Lilly

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

Data from randomised controlled trials suggests that Mounjaro leads to more average weight loss than Wegovy.

One study found that Mounjaro supported average weight loss of nearly 25% after one year. So, if you weighed 100kg, that would be a weight loss of 25kg.

In comparison, research on Wegovy suggests it supports an average weight loss of around 16% after one year, 9% less than Mounjaro.

A graphic showing the difference in weight loss between Mounjaro and Wegovy

Achieving over 10% weight loss is associated with clinically significant reductions in risk of chronic conditions such as type 2 diabetes and heart disease.

So, research suggests that Mounjaro leads to more average weight loss than Wegovy and may support more people achieving clinically significant weight loss of over 10%.

Key points:

  • Research suggests Mounjaro supports more average weight loss after one year
  • Average weight loss on Mounjaro after one year is around 25% and 16% on Wegovy
  • Research shows more participants achieve more than 10% weight loss on Mounjaro (~90%) than Wegovy (69%)

3) Mounjaro vs Wegovy: Which one should you choose?


Mounjaro is potentially more effective at supporting obesity and type 2 diabetes than Wegovy.

As demonstrated above, the higher doses of tirzepatide (the active ingredient in Mounjaro) appear to lead to greater weight loss and blood sugar reductions than semaglutide (Wegovy).

However, the two drugs haven’t been compared directly in double-blind, randomised controlled trials (the gold standard of medical research). So, we can’t say for sure which medication will prove more effective.

Additionally, Wegovy appears to have a slightly better safety profile than Mounjaro, with fewer side effects and fewer people stopping the medication due to adverse events.

So, if you were looking at trying GLP-1 medications for weight loss or blood sugar improvements, Mounjaro might be more effective, but you might find you’re more likely to stay on Wegovy.

However, individual medication responses differ significantly, so it’s worth speaking with your healthcare provider to determine what would be best for you.

Side effects and safety

All medications have possible side effects, particularly if you live with other health conditions.

Some will be mild but uncomfortable, such as cramping, and others will be more severe, such as shortness of breath. You must report any side effects you experience to your doctor and healthcare team when on medications.

Tirzepatide seems to be more effective at supporting weight loss than semaglutide but has a poorer safety profile.

In a randomised controlled trial with over 1800 participants comparing tirzepatide to semaglutide, the tirzepatide group reported more serious adverse events (5-7% VS 3%) and higher discontinuation rates due to adverse events (6-8.5% VS 4%).

Additionally, there were more deaths in the Tirzepatide group than semaglutide (12 vs 1). However, the researchers confirmed they didn’t believe these deaths were linked to the medication.


Mounjaro cost

Mounjaro will cost £9.95 on the NHS in England via prescription. Privately, Mounjaro starts from £229 a month as part of Second Nature’s Mounjaro weight-loss programme.

Wegovy cost

Second Nature’s Wegovy programme also starts from £229 per month and is designed to match the price of our Mounjaro programme.

Key points:

  • Mounjaro is more effective than Wegovy at supporting weight loss and blood sugar reductions
  • However, Wegovy seems to lead to fewer side effects and is better tolerated than Mounjaro
  • However, individuals will vary in their medication response, so choose the right one for you
  • Both medications start from £229 per month with Second Nature

Take home message

Weight-loss injections are designed as additional tools for healthy lifestyle change and shouldn’t be considered as lifelong medications.

Instead, they should be used to help you kickstart your weight-loss journey whilst you focus on building new, healthy habits.

Consider the use of antidepressants for people living with depression. They’re not designed to cure the condition. Instead, they’re designed to allow room for therapy to treat the condition’s underlying cause.

Mounjaro and Wegovy are similar. These medications can help silence food-related thoughts and also give you a boost of confidence with more immediate weight-loss results.

This helps to buy you the time and headspace to understand why your body may have struggled to lose weight previously, and to build new long-term healthy habits.

The core focus of our medication programmes are to calm down the feeling of food noise, lower your cravings, and to allow you to build healthier habits to keep the weight off for good.

The ultimate goal is to make losing weight feel second nature.

Second Nature’s medication-supported programmes

Second Nature has two medication-supported programmes: a Wegovy weight-loss programme and a Mounjaro weight-loss programme.

If you’ve decided to try Wegovy or Mounjaro (assuming you’re eligible), why should you choose Second Nature over other medication providers?

For peace of mind.

Second Nature has worked with the NHS for over 6 years providing weight-loss programmes across the UK.

Whilst our Wegovy and Mounjaro weight-loss programmes are private and not currently used by the NHS, we’ve built the programmes with a focus on scientific evidence, patient safety, and data security.

We hope that our 6+ years of working with the NHS and building a track record of effective weight-loss results will give you peace of mind to give us a try.

Check my eligibility

You might also like

Make losing weight feel Second Nature

The first step on your Second Nature journey is to take our health quiz.

Hand holding phone

Write a response

Lupe Rivera

29 February, 2024

Where are you located? Do you send to U.S.? I have a prescription, for Wegovy, but very hard finding it here in Georgia.

Robbie Puddick

5 March, 2024

Hi Lupe,

Unfortunately, our medication programmes are only available in the UK at the moment.


As seen on

The GuardianThe TimesChannel 4The Sunday Telegraph
Evening Standard