Jump to: Clinical differences between medications | Weight loss comparison | How to switch medications safely | Take home message
You can switch from Saxenda to Mounjaro, but you’ll need to start at Mounjaro’s lowest dose (2.5mg) regardless of your current Saxenda dose.
This transition typically takes 4-6 weeks as your body adjusts to the new medication.
Clinical research shows that switching between GLP-1 medications can benefit weight loss and blood sugar control.
However, temporary changes in appetite and side effects are common during the transition.
For UK patients in 2025, switching from Saxenda to Mounjaro requires careful planning and medical supervision.
The medications work differently – Saxenda is a daily injection targeting one hormone (GLP-1), while Mounjaro is a weekly injection targeting two hormones (GLP-1 and GIP).
Clinical differences between medications
Mounjaro and Saxenda differ in three key ways:
- Injection frequency: Mounjaro requires one injection weekly, while Saxenda needs daily injections
- Hormone targets: Mounjaro affects both GLP-1 and GIP hormones, while Saxenda only targets GLP-1
- Duration of action: Mounjaro maintains more consistent levels in your body over time compared to Saxenda’s daily fluctuations
These differences explain why the transition process requires starting at Mounjaro’s lowest dose – your body needs time to adjust to this new dual-action effect.
Weight loss comparison
Clinical research shows significant differences in weight loss outcomes between these medications:
Comparison Factor |
Saxenda |
Mounjaro |
Average Weight Loss |
6.4% |
25% |
Timeframe |
12 months |
12 months |
Dosing schedule |
Daily injection |
Weekly injection |
Time to maximum effect |
4-5 months |
6-8 months |
Hormones targeted |
GLP-1 only |
GLP-1 and GIP |
Research demonstrates that Saxenda achieves an average weight loss of 6.4%, while studies show Mounjaro can lead to weight loss of up to 25%.
This significant difference in effectiveness is likely due to Mounjaro’s dual-hormone action and weekly dosing schedule.
The medication maintains more consistent levels between doses, potentially leading to better appetite control.
How to switch medications safely
When transitioning from Saxenda to Mounjaro on Second Nature’s programme, you’ll follow these steps:
- Consultation with the clinical team to assess your eligibility
- Gradual dose reduction of Saxenda over 1-2 weeks
- Brief medication-free period (typically 2-3 days but maybe weeks)
- Start Mounjaro at 2.5mg weekly
- Gradual dose increases under medical supervision
During this transition, you might experience:
- Changes in appetite levels
- Different side effect patterns
- Temporary weight fluctuations
Our registered nutritionists and clinicians provide support throughout this process, helping you adjust your eating patterns and manage any side effects.

Take home message
Switching from Saxenda to Mounjaro may lead to better weight loss results and improved blood sugar control in the long term.
While the transition takes time, Mounjaro’s superior weight loss outcomes and weekly dosing schedule make it an attractive option for many patients.
Remember that these medications are tools to support your broader health journey, not lifetime solutions.
They create a window of opportunity to establish sustainable healthy habits while managing appetite and cravings.
Second Nature’s medication programme
Second Nature provides Mounjaro as part of our Mounjaro weight-loss programme.
Why should you choose Second Nature over other medication providers if you’ve decided to try Mounjaro (assuming you’re eligible)?
For peace of mind.
Second Nature has worked with the NHS for over 6 years, providing weight-loss programmes across the UK.
While our Mounjaro weight-loss programme is private and not currently used by the NHS, we’ve built the programme focusing 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.
Please note: We generally recommend speaking with your GP/doctor before you start taking any new medication like Mounjaro. If you do sign up for Second Nature's Mounjaro programme, then we'll also send your GP a letter to let them know you've started a medication-supported weight-loss journey.