Mounjaro vs Ozempic

Mounjaro and Ozempic are both injectable medications that contain a glucagon-like peptide 1 (GLP-1) receptor agonist. Mounjaro’s main active ingredient is tirzepatide, and Ozempic’s main active ingredient is semaglutide.

Ozempic is licensed in the UK to treat diabetes type 2. Mounjaro is licensed in the UK to treat both weight loss and type 2 diabetes.

Both medications are most effective when taken alongside a balanced healthy diet and exercise routine.

Mounjaro and Ozempic both contain GLP-1 (glucagon-like peptide 1) receptor agonists, however they each contain different active ingredients. Mounjaro contains tirzepatide, and Ozempic contains semaglutide.

Both Mounjaro and Ozempic are able to help with weight loss, according to some studies. However, only Mounjaro is licensed to be used as a treatment for weight loss in the UK, whereas Ozempic is not.

A range of clinical studies have assessed the effectiveness of tirzepatide (Mounjaro) and semaglutide (Ozempic) through a series of trials. Overall, tirzepatide (Mounjaro) has been found to be more effective for weight loss.

Effectiveness of Mounjaro (tirzepatide):

• 96.3% of people lose at least 5% of starting weight on the highest maintenance dose of 15mg after 72 weeks.
• 62.9% of people lose over 20% of their starting weight on the highest maintenance dose of 15mg after 72 weeks.

Effectiveness of Wegovy (semaglutide, the same active ingredient as Ozempic, but licensed for weight loss at a higher maximum maintenance dose):

• 89.4% of people lose at least 5% of starting weight on the highest maintenance dose of 2.4mg after 68 weeks.
• 30.2% of people lose over 20% of starting weight on the highest maintenance dose of 2.4mg after 68 weeks.

Studies comparing tirzepatide (Mounjaro) and semaglutide (Ozempic)

In a study assessing body weight changes in patients with type 2 diabetes and patients without type 2 diabetes, tirzepatide (Mounjaro) was more effective for weight loss compared to semaglutide (Ozempic). Over the course of 3 months, both patients with type 2 diabetes, and without type 2 diabetes:

• taking tirzepatide saw over 5% reduction in baseline weight
• taking semaglutide saw under 5% reduction in baseline weight

After one year (12 months) non- diabetic patients taking tirzepatide saw over 15% reduction in body weight, compared to those taking semaglutide who saw just 10% maximum change in body weight.

Further controlled clinical trials assessing tirzepatide vs semaglutide for type 2 diabetes outlined weight loss as an effect or factor of the treatment. Based on this, compared to placebo trials (false medication), tirzepatide (Mounjaro) was more effective for weight loss than semaglutide (Ozempic) to improve diabetes symptoms. These changes included:

• 9.57 kg reduction in body weight (in tirzepatide 15 mg) to 5.27 kg (tirzepatide 5mg)
• 4.97 kg reduction in body weight (semaglutide 2.0 mg) to 2.52 kg (semaglutide 0.5mg).

In a different study focusing on the dosages of tirzepatide (Mounjaro) 10mg and 15 mg compared with semaglutide (Ozempic) 2.4 mg for the treatment of weight loss, similar results were found. People were shown achieving 5% greater weight loss with tirzepatide than semaglutide over 72 weeks.

Therefore, although semaglutide (Ozempic) can help with weight loss, based on research, tirzepatide (Mounjaro) is proven to be a more effective targeted weight loss treatment, and is also licensed for this effect in the UK.

Mounjaro dosages

You should take Mounjaro once a week for 4 weeks, at first with a starting dose of 2.5 mg. After 4 weeks, your doctor should increase your dose, following a dosage schedule, depending on how well you’ve tolerated your previous dose.

The standard Mounjaro dosage schedule is as follows:

The maintenance dosages for Mounjaro are 5 mg, 10 mg and 15 mg.

To use Mounjaro, you should follow the ‘Instructions for Use’ manual that should come with the medication. It is injected under the skin:

• on the stomach
• upper leg (thigh)
• upper arm

You may need help from someone else to take and inject your dose of Mounjaro.

Ozempic dosages

You should take Ozempic once a week for 4 weeks, initially. After 4 weeks your doctor may increase your dosage, following a dosing schedule and depending on how well you cope with your previous dose.

The dosing schedule for Ozempic is as follows:

To use Ozempic, you should follow the ‘Instructions for Use’ manual that should come with the medication. It is injected under the skin:

• at the front of your thighs
• at the front of your waist
• upper arm

Before you use Ozempic, your doctor or nurse should show you how to use it. It should also come with instructions in the patient information leaflet.

Although the way of taking Mounjaro and Ozempic is similar they do not follow the same dosages.

Ozempic dosages are tailored to treat diabetes, whereas Mounjaro dosages are more targeted to treating weight loss.

A comparison of the dosages of Mounjaro and Ozempic:

The side effects of Mounjaro and Ozempic are similar, this is because they both contain medication from the same drug group (GLP-1).

However, note that Ozempic side effects are targeted towards those with type 2 diabetes because it is not licensed in the UK to treat weight loss.

A comparison of the Common, Uncommon, and Rare side effects across Mounjaro and Ozempic

There is more information about the potential side effects of Mounjaro and Ozempic in the patient information leaflets which you can find with the medications.

What should I do if I get side effects?

Common side effects of Mounjaro and Ozempic should pass once your body gets used to the medication.

To manage common side effects at home we recommend:

• Staying hydrated: Keeping hydrated and sipping cold drinks regularly should ease symptoms of sickness or nausea and dehydration.
• Avoiding alcohol: Alcohol will make you more dehydrated and increase side effects.
• Making changes to your diet and exercise routine: Ozempic and Mounjaro are most effective and safe when you follow a well balanced diet and exercise plan. Speak with your doctor for personalised advice on fitness and nutrition.
• Avoiding fatty or greasy foods: Fatty and/or greasy foods can increase symptoms of sickness or nausea due to their richness. We recommend eating small, frequent, bland meals including rice, toast and crackers.
• Avoiding citrus, spicy and acidic foods: Sometimes when taking Ozempic or Mounjaro, you may have increased symptoms of acid reflux and heartburn. Avoiding citrus, spicy or acidic foods can minimise these symptoms.

Ozempic is not licensed to be sold as a weight loss treatment in the UK and is not available on the NHS for this purpose. So it is likely you would have to pay full price of the medication. If it’s prescribed for managing diabetes it can cost just the standard prescription fee if you normally have to pay for your prescription, or it can be free.

You can purchase Mounjaro pens at ZAVA UK with 4 weeks of doses in them:

This comparison table reflects the reviews of Mounjaro and Ozempic on trusted medical patient review site, drugs.com:

*Note that because Ozempic is not licensed as a weight loss treatment in the UK, this rating is by patients who have type 2 diabetes.

Whilst taking Ozempic, it was reported that 51% of reviewers experienced a positive experience, while 26% reported a negative one. Negative experiences were typically associated with side effects, meanwhile positive experiences reported that they experienced weight loss.

Mounjaro on the other hand had 80% of reviewers reporting a positive experience, and only 7% reporting a negative one. Negative reviews state mainly that side effects were bothersome. Positive reviewers reflected on weight loss and feeling positive since taking the medication.

Can I switch from Ozempic to Mounjaro?

Yes, you can switch from Ozempic to Mounjaro, but you must only do so by following the specific instructions given by your doctor.

How do I switch?

When you consult your doctor to switch from Ozempic to Mounjaro, they will likely advise that you:

1. Stop taking Ozempic after your last dose is finished (unless you are switching due to side effects).
2. Wait at least 5 weeks before before starting Mounjaro. Your body needs time to get Ozempic out of your system. It needs to leave your system before you start new medication.
3. Start taking Mounjaro and following its dosage schedule. Even if you were taking the highest dosage of Ozempic, you will need to begin with the starting dose of Mounjaro.

Is it safe to switch?

Yes, if you are taking Ozempic for diabetes 2, it is safe to switch to Mounjaro for weight loss as long as you follow the instructions of your doctor.

Your doctor should ensure you follow certain guidelines that make sure your previous medication is out of your system before you begin taking a new one.

Since Mounjaro is licensed for weight loss for people without type 2 diabetes and Ozempic isn’t, unless you have type 2 diabetes, Mounjaro is a better choice.

Instead of Ozempic, you could consider Wegovy which has the same active ingredient but is licensed for weight loss. Then your choice would be between Wegovy and Mounjaro instead.

Comparing Wegovy and Mounjaro, Mounjaro has been shown to be more effective at helping people lose weight. Studies show that 96.3% of people lose at least 5% of starting weight on the highest Mounjaro maintenance dose of 15mg after 72 weeks. In comparison, 89.4% of people lose at least 5% of starting weight on the highest Wegovy maintenance dose of 2.4mg after 68 weeks.

Also, on drugs.com, Mounjaro is rated 9/10 for weight loss and Wegovy is rated 7.3/10.

Remember that if you try either Wegovy or Mounjaro first and it doesn’t work for you, you could switch to the other one with help from a doctor to see if it might work better.

If you are uncertain about self-injecting weight loss medication, there are oral tablet form alternatives such as:

• alli
• Xenical
• Orlistat

If you're unsure, you can get more information on weight loss treatments and explore all options available with us at ZAVA.