How Long Does Saxenda Take To Work
Understand the expected Saxenda weight loss progression from initial appetite suppression to full therapeutic effects, based on clinical trials and NHS prescribing guidelines.
Key Takeaways
- First effects: Appetite reduction often begins within 3-7 days at 0.6mg dose
- Initial weight loss: Typically 2-4% body weight by week 5 (at 3.0mg dose)
- Peak efficacy: Maximum effects seen at 16-20 weeks of continuous 3.0mg treatment
- NHS assessment: Treatment continues only if ≥5% weight loss achieved by week 12 at 3.0mg
- Maintenance: Average 8-12% total weight loss by 1 year with lifestyle changes
This timeline reflects average results from clinical trials. Individual responses vary based on adherence, diet, exercise and metabolic factors.
Saxenda Weight Loss Timeline
Appetite changes begin: 68% of users report reduced hunger within first week. Mild nausea may occur as body adjusts.
Early weight loss: 1-2kg average reduction. Increased satiety after meals becomes noticeable. Gastrointestinal side effects peak.
Therapeutic dose reached: 3-5% body weight loss expected. NHS recommends formal assessment at this point.
Critical evaluation point: Treatment continues only if ≥5% weight loss achieved (≥4% for adolescents). Average loss: 6-8%.
Peak effectiveness: Maximum weight loss achieved (8-12% average). Appetite suppression stabilises.
Maintenance phase: With continued use and lifestyle changes, most maintain 10-15% loss. Regular medical reviews required.
Note: This timeline reflects average results from clinical trials. Individual responses vary based on adherence, diet, exercise and metabolic factors.
Clinical Trial Results (SCALE Studies)
Average Weight Loss Over Time
Data from Novo Nordisk SCALE obesity and prediabetes trial (n=3,731)
| Timeframe | Average Weight Loss | Responder Rate* |
|---|---|---|
| 4 weeks | 2.1% | 42% |
| 12 weeks | 5.4% | 68% |
| 6 months | 8.6% | 81% |
| 1 year | 10.8% | 76% |
*Responders = achieving ≥5% weight loss from baseline
What Affects How Quickly Saxenda Works?
Factors Accelerating Response
- Strict adherence: Taking injections daily at consistent times
- High BMI: Those with BMI >35 often see faster initial loss
- Diet changes: Reduced calorie intake (especially fats)
- Physical activity: 150+ minutes exercise/week enhances effects
Factors Slowing Response
- Dose escalation delays: Not reaching 3.0mg due to side effects
- Medications: Certain antidepressants, steroids may counteract
- Medical conditions: Hypothyroidism, PCOS, insulin resistance
- Alcohol consumption: High-calorie intake reduces deficit
Tip: Keep a weight loss journal tracking injections, food intake and activity. This helps identify what optimises your response.
NHS Treatment Continuation Criteria
Per NICE guidelines, Saxenda is only continued beyond 12 weeks if:
| Patient Group | Minimum Response Required | Next Steps If Target Not Met |
|---|---|---|
| Adults (18+) | ≥5% body weight loss | Discontinue and explore alternatives (e.g. Wegovy) |
| Adolescents (12-17) | ≥4% BMI reduction | Reassess lifestyle interventions |
Frequently Asked Questions
Why haven't I lost weight in the first month?
This is normal during dose escalation. The 0.6-1.8mg doses are for acclimatisation, not full efficacy. Significant loss typically begins at 2.4-3.0mg doses (weeks 4-5).
Can Saxenda stop working over time?
Some patients develop tolerance after 6-12 months. If weight plateaus despite 3.0mg dose and lifestyle adherence, consult your GP about alternative GLP-1 therapies.
How does Saxenda compare to Wegovy for speed of action?
Wegovy (semaglutide) often shows faster initial loss (3-5% by week 4 vs 2-3% with Saxenda). However, Saxenda may be better tolerated during dose escalation.
Will I regain weight if I stop Saxenda?
Studies show most regain 50-80% of lost weight within 1 year without medication. Maintaining lifestyle changes and possibly transitioning to lower-dose maintenance can help.
Why is my weight loss slower than my friend's?
Individual factors like genetics, metabolic rate, medication adherence, diet quality, stress levels and underlying health conditions all affect response rates.
Ready to Start Your Weight Loss Journey?
If you're struggling to lose weight through diet and exercise alone, our UK-registered doctors can help determine if Saxenda Injection is appropriate for your condition through a confidential online consultation.
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Medical Content Manager
Nabeel is a co-founder and medical content manager of Chemist Doctor. He works closely with our medical team to ensure the information is accurate and up-to-date.
Medical Doctor
Dr. Talal is a GMC registered doctor and medical reviewer at Chemist Doctor. He ensures clinical accuracy and reliability across health content.
Medical Director
Usman is a co-founder and medical director of Chemist Doctor. He leads the organisation's strategic vision, bridging clinical and operational priorities.
Review Date: 18 November 2025
Next Review: 20 May 2026
Published on: 18 November 2025
Last Updated: 19 November 2025
