Jump to: How 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
Based on an indirect analysis of individual studies, the higher doses of Mounjaro (10mg & 15mg) are more effective for weight loss and blood sugar than Wegovy.
However, no studies have compared the two medications directly against one another in a double-blinded randomised controlled trial (where neither the researchers nor the participants know which medication they’ve been given).
Additionally, a large study that compared Mounjaro to Ozempic (a lower dose version of Wegovy) found that Mounjaro led to more side effects and adverse events than Ozempic.
So, if you’re looking for a medication to help you lose weight and improve your blood sugar levels, the higher doses of Mounjaro will likely lead to more weight loss and blood sugar reductions than Wegovy.
Still, you might find you’re better able to tolerate Wegovy and may stay on the medication longer, making it more effective for you.
However, individual responses to medications vary between individuals. Be mindful of side effects and contact your healthcare team to determine the appropriate medication and dosage.
Due to the shortage of semaglutide (Ozempic) in the UK, we aren’t accepting new prescriptions for our medication-supported programme.
However, you can join our waiting list when our Wegovy-supported programme restarts by clicking here.
What are Mounjaro and Wegovy?
Mounjaro and Wegovy are GLP-1 receptor agonists, medications that reduce appetite to support weight loss and improve blood glucose control through various mechanisms.
Mounjaro – in addition to being a GLP-1 medication – is also a glucose-dependent insulinotropic polypeptide (GIP) mimetic.
GIP is a hormone in the body that supports blood glucose levels and helps our fat cells store more excess energy we might consume in our diets.
So, Mounjaro has a dual function that mimics two hormones in the body that support blood glucose levels and weight loss.
Wegovy is manufactured by Novo Nordisk, while Mounjaro is by Eli Lilly. The active ingredient in Mounjaro is tirzepatide, and semaglutide in Wegovy.
Mounjaro is approved for individuals living with type 2 diabetes in the U.S., and Wegovy is approved for individuals living with Obesity.
They were initially approved as prescription drugs but are now widely available online for private purchase.
Wegovy is available in the UK this year, but Mounjaro is still seeking approval, and it’s unclear when this will happen.
Both medications have similar dosing schedules and are administered once a week. The main difference is the amount of medication used. The volume of the doses with Mounjaro is larger than with Wegovy.
Dosing schedules:
Not a magic pill
These medications are designed as additional tools for weight management interventions and shouldn’t be considered lifelong medications.
Instead, they should be used to help you kickstart your weight loss and healthy journey while you commit to living a healthier lifestyle.
At Second Nature, we’ve been trusted by the NHS since 2017 to support people with type 2 diabetes and obesity to lose weight and manage their blood sugar levels and lead healthier lifestyles for the long term.
If you’re considering purchasing Mounjaro (when it’s available in the UK) or Wegovy but need support in making positive changes to your lifestyle, Second Nature could be an option for you.
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.
Due to the shortage of semaglutide (Ozempic) in the UK, we aren’t accepting new prescriptions for our medication-supported programme.
However, you can join our waiting list when our Wegovy-supported programme restarts by clicking here.
Otherwise, keep reading as we dig into the science of Mounjaro and Wegovy and how GLP-1s work.
1) How do Wegovy and Mounjaro work?
When we eat food, our gut releases a hormone that helps the body regulate hunger and blood sugar levels. This hormone is called GLP-1 (glucagon-like peptide-1). The actions of GLP-1 are the target of Wegovy and Mounjaro.
This class of medications are known as GLP-1 receptor agonists (GLP-1s). They mimic the actions of the hormone GLP-1.
GLP-1s improve insulin function to lower blood sugar levels and delay gastric emptying, decreasing appetite. GLP-1s also communicate with the brain’s appetite control centre, the hypothalamus, to lower food-seeking behaviour.
Additionally, GIP is a hormone also released in response to food and helps to regulate blood sugar levels and helps our fat cells ‘absorb’ more excess energy, which prevents fat from being stored in the liver or pancreas.
The medications that mimic GIP are known as GIP mimetics. These additional actions are the target of Mounjaro, which is a dual-action type 2 diabetes medication.
There are two well-known GLP-1 medications available in the UK and U.S.:
Liraglutide (Saxenda): Taken once a day
Semaglutide (Ozempic and Wegovy): Taken once a week
Currently, there’s only one dual-action GLP-1 and GIP mimetic medication available in the U.S. (not currently available in the UK):
Tirzepatide (Mounjaro): Taken once a week
Do GLP-1 receptor agonists and GIP mimetics work?
Clinical trials have demonstrated that GLP-1s are more effective at weight loss than other weight loss medication drugs like orlistat, which has a different mode of action.
A systematic review and meta-analysis (a study analysing lots of different studies) analysed 28 trials in over 29,000 people investigating the effectiveness of five weight loss medications on weight loss.
The study found that all five medications were more effective than the placebo at supporting weight loss.
This trial included orlistat and the GLP-1 liraglutide and found that liraglutide was more effective at weight loss than orlistat and showed that participants taking liraglutide were twice as likely to achieve more than 5% weight loss than orlistat.
Due to the relationship between obesity, blood sugar levels, and cardiovascular disease, research shows a positive relationship between GLP-1s and heart disease risk factors such as high blood pressure (hypertension) and triglyceride levels.
Interestingly, more recent studies have shown that semaglutide (Ozempic and Wegovy) is more effective at supporting weight loss and type 2 diabetes than liraglutide (Saxenda).
Even more recent trials suggest that tirzepatide (Mounjaro) is more effective than semaglutide (Ozempic and Wegovy) at supporting weight loss and type 2 diabetes.
Key points:
- GLP-1 receptor agonists (GLP-1s) are a class of medications that mimic the actions of the hormone GLP-1, which helps regulate hunger and blood sugar levels
- GLP-1s help the pancreas release more insulin, delay stomach emptying, and reduce appetite
- GIP mimetics mimic the action of the hormone GIP, which improves insulin secretion to lower blood glucose and helps the body store fat in the adipose tissue, protecting the internal organs from excess energy storage
- Two well-known GLP-1 medications in the UK and U.S. are liraglutide (Saxenda) and semaglutide (Wegovy and Wegovy)
- Mounjaro is the only GLP-1+GIP mimetic medication currently available in the U.S., its release in the UK is not known
- Research has suggested that GLP-1s are more effective at supporting weight loss than other weight loss medication drugs like Orlistat
- A systematic review and meta-analysis found that all five weight loss medications investigated were more effective than placebo at supporting weight loss
- Liraglutide was more effective at weight loss than orlistat. Semaglutide is more effective at supporting weight loss and type 2 diabetes than liraglutide; at the same time, tirzepatide is more effective than semaglutide.
2) Mounjaro and Wegovy for weight loss and type 2 diabetes
Type 2 diabetes
The hormone GLP-1 binds to GLP-1 receptors in the pancreas to increase insulin release after a meal. It also prevents the body from releasing too much glucagon, a hormone that increases blood sugar levels.
These two mechanisms support individuals living with type 2 diabetes in managing their blood glucose levels on a meal-to-meal basis.
Research has shown that GLP-1s are effective at reducing blood glucose for people living with type 2 diabetes.
Liraglutide (Saxenda) was one of the earlier forms of longer-lasting GLP-1s and reduces HbA1c (average blood glucose) levels by around 1.3% on average and fasting plasma glucose by 2 mmol/L.
In comparison, semaglutide (Wegovy) reduces HbA1c by around 1.8% on average and fasting plasma glucose by 2.8mmol/L.
Semaglutide (Wegovy) is more effective at reducing blood sugar levels than liraglutide (Saxenda). Interestingly, a new version of GLP-1s known as tirzepatide (Mounjaro) may be more effective than semaglutide.
Tirzepatide is a dual-action type 2 diabetes medication. Alongside its effects on GLP-1, it also mimics the actions of another hormone called GIP (gastric inhibitory polypeptide) that reduces blood sugar levels.
A randomised controlled trial in 1897 of individuals with type 2 diabetes compared the impact of three doses of tirzepatide (5mg, 10mg, and 15mg) to a once-weekly injection of 1mg semaglutide (Ozempic) on blood sugar levels.
The results showed that all three doses of tirzepatide led to more significant HbA1c reductions than 1mg of semaglutide.
Tirzepatide hasn’t been compared to the higher dose of semaglutide (Wegovy) now available.
However, researchers have compared the impact of both drugs from different studies (this is called an indirect analysis) and suggested that the higher doses (10mg and 15mg) of tirzepatide might reduce HbA1c by 0.36% more than 2mg of semaglutide.
In comparison, there was no difference between 5mg of tirzepatide compared to 2mg of semaglutide. 2mg isn’t the 2.4mg dose available with Wegovy, so it remains unclear how the higher doses of Mounjaro compare to Wegovy.
Liraglutide and semaglutide are available in the UK and the U.S. to treat type 2 diabetes.
However, tirzepatide is only available in the U.S. after getting FDA approval in 2022; the UK will likely approve tirzepatide in the not-to-distant future.
So, GLP-1 receptor agonists significantly reduce blood sugar levels and are an effective treatment for type 2 diabetes—particularly the longer-lasting and recent versions of GLP-1s, semaglutide and tirzepatide.
Interestingly, the lasting effect of GLP-1s to support type 2 diabetes might be its impact on reducing appetite and supporting weight loss than the impact it has on the pancreas.
Weight loss
Compared to lifestyle interventions without medications, GLP-1-assisted programmes have been shown to lead to a more clinically significant weight loss of 10% or more.
Losing and maintaining weight loss of more than 10% is associated with significantly reducing complications associated with obesity, including hypertension, type 2 diabetes, and heart disease.
A recent paper published in The Lancet showed that nearly 20% of participants in lifestyle interventions without medications gain weight, around 40% lose between 1-10% of their body weight, and just 13% lose more than 10%.
In comparison, less than 5% of participants combining semaglutide with lifestyle interventions gain weight, around 10% lose between 1-10%, and 87% lose more than 10%.
So, 47% more people lose more than 10% of body weight on lifestyle interventions with semaglutide compared to lifestyle interventions alone.
Interestingly, recent trials have shown that tirzepatide is more effective than semaglutide.
A randomised controlled trial in 1897 of individuals living with type 2 diabetes compared the impact of three doses of tirzepatide (5mg, 10mg, and 15mg) compared to a once-weekly injection of 1mg semaglutide (Ozempic) on blood sugar levels.
The results showed that all three doses of tirzepatide led to more significant weight loss than 1mg of semaglutide.
As mentioned above, tirzepatide hasn’t been compared to the higher dose of semaglutide (Wegovy) now available.
However, researchers have compared the impact of both drugs from different studies and suggested that the higher doses (10mg and 15mg) of tirzepatide might reduce weight by 5.15kg more than 2mg of semaglutide.
In comparison, there was no difference between 5mg of tirzepatide compared to 2mg of semaglutide. 2mg isn’t the 2.4mg dose available with Wegovy, so it remains unclear how the higher doses of Mounjaro compare to Wegovy.
So, GLP-1s lead to clinically significant weight loss rarely observed in intervention trials that use lifestyle interventions without medications.
Semaglutide is more effective than liraglutide, and tirzepatide appears more effective than semaglutide.
3) Mounjaro vs. Wegovy: Which one should you choose?
Effectiveness
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 with one another 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 responses to medications differ greatly, 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.
Ttirzepatide 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.
Cost
Mounjaro®
Mounjaro isn’t currently available in the UK. In the US, the cost of Mounjaro on a monthly basis will depend on various factors, such as your prescription drug insurance plan, your pharmacy, and any available discounts or savings programmes.
However, the current retail cost for Mounjaro is around $1500 a month.
Wegovy®
The cost depends on where you’re purchasing it from and how long you intend to use the medication. However, to purchase the medication and injectable pens required for four weeks would cost around £126, or around £1520 per year.
In the U.S., the cost will depend on your insurance coverage, any discounts available, and your pharmacy. Typically, it will start at a lower cost of around $25 a month and rise after 6 months to around $1500.
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
- Wegovy® is currently available in the UK and the U.S.
- Mounjaro® is only available in the U.S. at the moment, the UK is yet to confirm when the drug will be made available
- Both medications are expensive if you opt to purchase them privately
- Currently, only Wegovy® is available to purchase in the UK outside of a prescription and would cost around £160 a month whilst you’re taking the medication
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.
The harsh reality is that we still don’t know the long-term effects of these medications on our health. There are examples of drugs being withdrawn from the market as more long-term data comes to light.
Lorcaserin was a weight loss drug approved by the Food and Drug Administration (FDA) in the U.S. but was recently withdrawn as data indicated that it increased cancer risk.
The example of lorcaserin is why you must weigh the pros and cons when your doctor prescribes medication or before you purchase it yourself and start treatment. Report any side effects to your healthcare team.
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, Second Nature has launched a new GLP-1-supported weight loss programme.
Due to the shortage of semaglutide (Ozempic) in the UK, we aren’t accepting new prescriptions for our medication-supported programme.
However, you can join our waiting list when our Wegovy-supported programme restarts by clicking here.
