Which Mounjaro Dose Is the Most Cost-Effective for Weight Loss?
Mounjaro (tirzepatide) is one of the most effective weight-loss medications currently available in the UK. However, with multiple dose options 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg and many patients paying privately, it's really important to know which dose is the most cost effective for the amount of weight loss you achieve.
So which dose provides the most weight loss per pound spent?
This analysis compares:
- Clinical trial weight-loss outcomes
- Typical UK private pricing
- The relationship between dose increases and diminishing returns
We examined clinical trial data on efficacy alongside typical UK private prescription pricing, exploring how dose increases relate to diminishing returns in both weight loss and cost-effectiveness.
What Do the Clinical Trials Show About Weight Loss by Dose?
The most robust evidence comes from the SURMOUNT-1 trial (72 weeks).This trial was a pivotal phase 3 clinical study designed to evaluate the efficacy and safety of tirzepatide (Mounjaro) for weight management in adults with obesity or overweight conditions. It spanned 72 weeks and included participants both with and without type 2 diabetes.
The trail showed an average percentage bodyweight reduction:
| Dose | Average Weight Loss |
|---|---|
| 5 mg | 15% |
| 10 mg | 19.5% |
| 15 mg | 21–22.5% |
- The largest improvement occurs between 5 mg and 10 mg
- The increase from 10 mg to 15 mg is comparatively small
- Weight loss begins to show diminishing returns at higher doses
Then you compare the weight loss for typical UK pricing (4-Week Supply)
Private prescription prices vary by provider. Typical ranges are:
| Dose | Approx Monthly Cost (£) |
|---|---|
| 5 mg | £170–£250 |
| 7.5 mg | £210–£300 |
| 10 mg | £240–£330 |
| 12.5 mg | £260–£350 |
| 15 mg | £280–£360 |
Prices generally increase progressively with dose strength.
Estimating Cost-Effectiveness
To compare value, we can examine:
Weight loss percentage ÷ monthly cost
5 mg
- 15% weight loss
- £170–£250 per month
- Lower total weight reduction
10 mg
- 19.5% weight loss
- £240–£330 per month
- Substantial improvement compared to 5 mg
15 mg
- 21–22% weight loss
- £280–£360 per month
- Smaller incremental benefit over 10 mg
Which Dose Appears Most Cost-Effective?
Based on clinical averages and typical UK private pricing:
10 mg appears to offer the strongest balance between cost and efficacy.
It provides:
- A significant increase in weight loss compared to 5 mg
- Much of the medication’s total potential effect
- A smaller relative cost increase compared to the benefit gained
- Better weight-loss-per-pound value than 15 mg in most pricing models
Why Not 15 mg?
While 15 mg produces the highest average weight loss, the additional benefit over 10 mg is modest relative to the higher cost.
Why Not 5 mg?
Although more affordable, 5 mg produces significantly less total weight loss for patients aiming for substantial reductions.
Important Considerations
- Individual response varies significantly
- Some patients achieve excellent results at lower doses
- Others may plateau at 10 mg
- Higher doses may increase the risk of side effects
- Clinical trial averages may differ from real-world outcomes
Dose decisions should always be individualised under medical supervision.