What Is Liraglutide (Saxenda)? Uses, Dosage & How It Works
Liraglutide is a prescription-only GLP-1 receptor agonist sold under two brand names in the UK: Saxenda (3 mg, for chronic weight management) and Victoza (1.2–1.8 mg, for type 2 diabetes). Originally developed as a diabetes treatment, its pronounced appetite-suppressing properties led Novo Nordisk to develop the higher-dose Saxenda formulation specifically for obesity management. This guide explains the pharmacology, clinical uses, dosing, half-life, safety profile, and the important distinctions between Saxenda and Victoza.
What Is Liraglutide?
Liraglutide is a synthetic analogue of glucagon-like peptide-1 (GLP-1) — an incretin hormone produced naturally by L-cells in the small intestine in response to eating. The synthetic molecule shares approximately 97% amino acid sequence homology with human GLP-1, with a fatty acid side chain that extends its half-life from a few minutes (native GLP-1) to approximately 13 hours.
It belongs to the GLP-1 receptor agonist class of medications — a group that includes semaglutide (Ozempic, Wegovy) and, at the dual-agonist level, tirzepatide (Mounjaro). Liraglutide was the first once-daily GLP-1 receptor agonist to receive MHRA and FDA approval and has now accumulated more than ten years of post-market safety data across its two indications.
Liraglutide is available under two brand names at different doses for different licensed indications: Saxenda (3 mg once daily — weight management) and Victoza (1.2 mg or 1.8 mg once daily — type 2 diabetes). These products must never be used interchangeably.
Licensed Uses: Saxenda and Victoza
Liraglutide has two distinct licensed clinical indications in the UK, each at a different dose and for a different patient population.
Saxenda (liraglutide 3 mg) — weight management
Saxenda is licensed for chronic weight management in adults with a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related comorbidity. It is recommended by NICE in Technology Appraisal TA664 and is used alongside a calorie-controlled diet and increased physical activity. For a full clinical guide to Saxenda, see our Saxenda injections guide.
Victoza (liraglutide 1.2–1.8 mg) — type 2 diabetes
Victoza is used to improve blood glucose control in adults with type 2 diabetes mellitus, alongside dietary changes and other diabetes medications. It is typically prescribed when other oral diabetes treatments have not achieved adequate glycaemic control. Victoza also demonstrates modest weight loss benefits, which contributed to the rationale for developing the higher-dose Saxenda formulation.
Important: Saxenda and Victoza have different licensed indications, doses, and clinical pathways. They must not be used interchangeably. Always use the product specifically prescribed to you and at the dose prescribed.
How Liraglutide Works for Weight Loss
In people with obesity, GLP-1 signalling is often reduced — a physiological deficit that contributes to impaired satiety regulation and increased calorie intake. Liraglutide directly addresses this deficit by activating GLP-1 receptors at pharmacological doses. Its effects on weight operate through several complementary pathways.
Hypothalamic appetite control
Activates GLP-1 receptors in the hypothalamus, the brain’s primary appetite regulation centre, increasing satiety signals and reducing hunger drive.
Delayed gastric emptying
Slows the rate at which food leaves the stomach, prolonging the mechanical sensation of fullness and extending the post-meal satiety period.
Insulin and glucagon regulation
Stimulates glucose-dependent insulin secretion and suppresses glucagon release, stabilising blood sugar and preventing the energy crashes that trigger between-meal hunger.
Sustained calorie deficit
The combined effect of reduced hunger, earlier fullness, and stable blood sugar produces a consistent, tolerable calorie deficit — the metabolic basis for progressive weight loss.
The practical result for patients: you feel full more quickly at mealtimes, are satisfied with smaller portions, experience fewer cravings between meals, and enter a natural calorie deficit without the extreme hunger associated with unsupported calorie restriction. For a comparison of this single-pathway mechanism with the dual GIP/GLP-1 mechanism of tirzepatide (Mounjaro), see our Mounjaro vs Saxenda comparison guide.
How Long Does Liraglutide Stay in Your System?
The pharmacokinetic profile of liraglutide is well characterised from clinical studies and explains both its once-daily dosing schedule and the timeline of effects after stopping treatment.
~13h
Elimination half-life of liraglutide
~26h
Effective duration of action per dose
2–4
Days to clear system after last dose
With a half-life of approximately 13 hours, a single injection of liraglutide remains pharmacologically active for around 26 hours — slightly overlapping the 24-hour dosing interval, which maintains consistent plasma levels and sustained receptor activation throughout the day. This is why once-daily dosing is both effective and appropriate.
After stopping Saxenda, the drug clears the system completely within approximately two to four days. The appetite-suppressing effect diminishes noticeably within 24–48 hours of the last dose, which underscores the importance of gradual, medically supervised discontinuation rather than abrupt stopping.
Do not stop Saxenda without consulting your prescriber. Abrupt discontinuation can lead to a rapid return of appetite and calorie intake. Your prescriber will advise on an appropriate plan if treatment is to be stopped or transitioned to another medication.
Safety Profile
Liraglutide is considered a well-characterised, established medication with both MHRA and FDA approval and over a decade of post-market safety data from millions of patients worldwide. Its safety profile is consistent across both the Saxenda and Victoza formulations.
Common side effects
- Nausea — most common, particularly during dose escalation; typically improves within 4–8 weeks at the stable maintenance dose
- Diarrhoea
- Constipation
- Vomiting
- Headache
- Fatigue — usually transient, most pronounced in early weeks
- Injection site reactions — redness, itching, bruising; rotate sites to minimise
Uncommon but serious side effects
- Pancreatitis — seek urgent medical attention for severe, persistent abdominal pain
- Gallbladder disease — including gallstones; reported in weight-loss trials
- Increased resting heart rate — a sustained elevation should be discussed with your prescriber
Stop liraglutide immediately and seek urgent medical attention if you experience: severe or persistent abdominal pain (possible pancreatitis); signs of an allergic reaction such as facial or throat swelling, difficulty breathing, or widespread rash; or any rapidly developing serious symptoms. Contact your GP or call 999.
Who liraglutide is not suitable for
- People who are pregnant or breastfeeding
- Personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN2)
- History of pancreatitis
- Currently taking another GLP-1 receptor agonist or dual GIP/GLP-1 agonist
- Severe renal or hepatic impairment (subject to prescriber assessment)
Saxenda vs Victoza: Key Differences
Both Saxenda and Victoza contain liraglutide, but they are distinct products with different licensed indications, doses, and clinical pathways. They must not be used interchangeably under any circumstances.
| Feature | Saxenda (liraglutide 3 mg) | Victoza (liraglutide 1.2–1.8 mg) |
|---|---|---|
| Licensed indication | Chronic weight management | Type 2 diabetes mellitus |
| Approved dose | 3 mg once daily (maintenance) | 1.2 mg or 1.8 mg once daily |
| Primary treatment target | Obesity / excess body weight | Blood glucose (HbA1c) control |
| NICE guidance | TA664 (weight management) | Separate diabetes technology appraisals |
| Eligibility | BMI ≥30, or 27–29.9 + comorbidity | Adults with type 2 diabetes |
| Interchangeable? | No — different doses and indications; always use the product specifically prescribed | |
If you have been prescribed Saxenda for weight management, do not use Victoza as a substitute, and vice versa. If you have questions about your prescribed product or dose, contact your prescriber or pharmacist.
Getting Liraglutide in the UK
Liraglutide (both Saxenda and Victoza) is a prescription-only medicine (POM) in the UK. It cannot be purchased over the counter or without a valid prescription from a qualified prescriber. There are three routes to accessing it:
- NHS GP: Your GP can prescribe liraglutide if you meet the clinical criteria. NHS availability of Saxenda for weight management may vary by local Integrated Care Board (ICB) and NHS funding decisions.
- NHS specialist weight management service: For patients with complex obesity, referral to a specialist tier 3 or tier 4 weight management service may be appropriate.
- GPhC-registered private online pharmacy: Access Doctor (GPhC #9011198) offers a regulated online consultation for weight loss medications, reviewed by GMC-registered independent prescribers.
For a full overview of all UK-licensed weight loss medications and how to choose between them, see our guide on what weight loss medication is.
In-depth guide
Saxenda (liraglutide 3 mg)
Dosage schedule, clinical results, side effects, and how to get Saxenda through a GPhC-registered pharmacy.
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Start Your ConsultationFrequently Asked Questions
What is liraglutide used for?
Liraglutide is used for two distinct licensed indications: chronic weight management (as Saxenda 3 mg) in adults with a BMI of 30 kg/m² or above, or 27 kg/m² or above with a weight-related comorbidity; and the treatment of type 2 diabetes mellitus (as Victoza 1.2–1.8 mg) to improve blood glucose control alongside diet and other diabetes medications.
How does liraglutide work for weight loss?
Liraglutide activates GLP-1 receptors in the hypothalamus to increase feelings of fullness and reduce hunger, slows gastric emptying to prolong satiety, and stabilises blood sugar by stimulating insulin and suppressing glucagon. The combined effect is a consistent, tolerable reduction in appetite and calorie intake, facilitating progressive weight loss without extreme hunger.
How long does liraglutide stay in your system?
Liraglutide has an elimination half-life of approximately 13 hours, meaning it remains pharmacologically active for around 26 hours after a single injection — the basis for its once-daily dosing schedule. After stopping treatment, the drug clears the system completely within approximately two to four days. Appetite-suppressing effects diminish noticeably within 24–48 hours of the last dose.
Is liraglutide safe?
Liraglutide has received both MHRA and FDA approval and has accumulated more than ten years of post-market safety data. It is considered a well-characterised medication when used as prescribed. The most common side effects are gastrointestinal — particularly nausea during dose escalation — and typically improve over time. Serious side effects, including pancreatitis and gallbladder disease, are uncommon. As with all prescription medications, it must be used under the supervision of a qualified prescriber.
What is the difference between Saxenda and Victoza?
Both contain liraglutide but at different doses for different licensed indications. Saxenda (3 mg once daily) is licensed for chronic weight management. Victoza (1.2 mg or 1.8 mg once daily) is licensed for type 2 diabetes. They are distinct products with different NICE guidance, different eligibility criteria, and must never be used interchangeably. Always use the product specifically prescribed to you.
Can I get liraglutide (Saxenda) online in the UK?
Yes — Saxenda can be prescribed and dispensed through a GPhC-registered online pharmacy following a regulated clinical consultation. Access Doctor (GPhC #9011198) offers an online assessment reviewed by a GMC-registered independent prescriber. If clinically appropriate, your prescription is issued and medication dispatched in discreet packaging. Visit our weight loss treatment page to begin.
References
- NICE Technology Appraisal TA664. Liraglutide for managing overweight and obesity. National Institute for Health and Care Excellence; 2020.
- Novo Nordisk. Saxenda (liraglutide 6 mg/mL) Summary of Product Characteristics. Current version.
- Mehta A, et al. Liraglutide for weight management: a critical review of the evidence. Obesity Science & Practice. 2017;3(1):3–14.
- NHS. Obesity — treatment. NHS.uk. Accessed March 2026.
- NICE Clinical Guideline CG189. Obesity: identification, assessment and management. National Institute for Health and Care Excellence; 2014 (updated 2023).
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Liraglutide (Saxenda and Victoza) is a prescription-only medicine (POM) and must only be used under the supervision of a qualified prescriber. Always consult a healthcare professional regarding your individual circumstances. Do not stop or start any prescription medication without medical guidance.