Wegovy vs Mounjaro

Both medicines help with weight loss by reducing appetite and helping you feel full sooner. The key difference is how many “signals” in the body they act on.

Wegovy: mimics one hormone (appetite)

Wegovy works by copying a one natural hormone in your body called GLP-1.

In simple terms, it:

• Tells your brain you are full, so you feel less hungry
• Slows how quickly food leaves your stomach, helping you stay satisfied for longer
• Helps control blood sugar levels

Think of Wegovy as one strong signal that reduces appetite and helps you eat less.

Mounjaro: mimics two hormones (appetite and metabolism)

Mounjaro works on two natural hormones: GLP-1 and GIP.

It does everything Wegovy does and more:

• Reduces hunger and increases fullness
• Slows digestion, so you feel satisfied longer
• Improves how your body handles sugar and fat, helping your metabolism work more efficiently

You can think of Mounjaro as sending two signals instead of one, which is why many people lose more weight on it.

Comparing mechanisms of action

When we look at studies that directly compare the two medicines, Mounjaro generally leads to more weight loss than Wegovy.

Overview

What this means for you

Average weight loss

• Wegovy: People typically lose about 19-21% of their starting weight after 72 weeks of treatment.
• Mounjaro: People usually lose about 18–22.5% of their starting weight in similar timeframes.

Mounjaro generally leads to more weight loss than Wegovy.

Clinically meaningful weight loss (≥20%)

• With Wegovy, approximately 30–35% of patients get to 20% or more weight loss.
• With Mounjaro, around 45–55% of patients reach 20% or more weight loss.

Nearly half (or more) of people on Mounjaro hit ≥20% weight loss, significantly higher than Wegovy.

Wegovy and Mounjaro both act on similar gut hormones, therefore many of their side effects, especially gastrointestinal symptoms like nausea, vomiting, and diarrhoea, are similar.

Further reading: Mounjaro Side Effects

Further reading: Wegovy Side Effects

When comparing Wegovy and Mounjaro, the cost difference can be substantial. Wegovy tends to be cheaper over a year, especially once maintenance doses are reached.

Although Mounjaro may produce slightly greater average weight loss of up to 22.5% compared to 17% with Wegovy, this potential benefit is associated with a higher treatment cost.

Further reading: Switching from Mounjaro to Wegovy

Both Wegovy and Mounjaro are increased gradually over time, which helps your body adjust and reduces the chance of stomach-related side effects.

This step-by-step approach makes treatment safer and easier to tolerate.

The chart below shows how the doses are increased over time, making it easier for you to choose the right starting point and long-term dose for safe, effective weight-loss treatment.

The best choice depends on your individual health needs, weight-loss goals, cost, and a discussion with your healthcare provider.

Wegovy may be right for you if:

• Cost is a key consideration, and you are prepared to accept a slightly lower level of weight loss in exchange for affordability.

*It is important to note that meaningful cost savings are generally seen only up to a maintenance dose of 2.4mg, which is associated with average weight loss of up to 17%. For the higher dose of Wegovy 7.2mg (associated with an average weight loss of 19-21%, Wegovy is more expensive than Mounjaro 15mg, which has an average weight loss potential of up to 22.5%).

Mounjaro may be right for you if:

• Achieving the greatest possible weight loss is your main goal
• You are using Wegovy 7.2mg and finding it expensive (Mounjaro 15mg is cheaper and produced better weight loss results in clinical trials)
• You have type 2 diabetes
• You did not get the results you wanted from GLP-1-only treatments