Liraglutide and obesity treatment represents a significant advancement in pharmacological weight management for adults and adolescents in the UK. As a glucagon-like peptide-1 (GLP-1) receptor agonist, liraglutide 3.0 mg (Saxenda®) is licensed by the MHRA for weight loss in patients with obesity or overweight with weight-related comorbidities. This medication works by mimicking natural gut hormones that regulate appetite and satiety, helping patients reduce energy intake when combined with dietary modification and increased physical activity. NICE recommends liraglutide within specialist tier 3 weight management services for eligible patients, though NHS availability varies across the UK due to local commissioning decisions.

What Is Liraglutide and How Does It Work for Weight Loss?

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist originally developed for the treatment of type 2 diabetes mellitus. At a higher dose (3.0 mg daily), it is licensed in the UK under the brand name Saxenda® specifically for weight management in adults with obesity or overweight with weight-related comorbidities, and in adolescents aged 12–17 years with obesity. The Medicines and Healthcare products Regulatory Agency (MHRA) approved this indication following clinical trials demonstrating significant weight reduction compared to placebo.

Liraglutide is indicated only as an adjunct to a reduced-calorie diet and increased physical activity. The mechanism of action centres on mimicking the naturally occurring hormone GLP-1, which is released from the intestine in response to food intake. Liraglutide binds to GLP-1 receptors in multiple tissues, including the pancreas, gastrointestinal tract, and brain. In the hypothalamus, it acts on appetite-regulating centres to reduce hunger and increase feelings of satiety. This may help patients reduce their energy intake, but dietary modification and increased physical activity remain essential components of treatment.

Additionally, liraglutide slows gastric emptying, which prolongs the sensation of fullness after meals and helps regulate postprandial glucose levels. In the pancreas, it enhances glucose-dependent insulin secretion and suppresses inappropriate glucagon release. These combined effects contribute to weight loss through reduced energy intake and improved metabolic regulation. Liraglutide is administered once daily via subcutaneous injection using a pre-filled pen device, with dose titration over several weeks to minimise gastrointestinal side effects and improve tolerability.

References: EMC SmPC: Saxenda (liraglutide) 6 mg/mL solution for injection; EMA EPAR: Saxenda.

Who Can Use Liraglutide for Obesity Treatment in the UK?

According to NICE technology appraisal guidance (TA664), liraglutide 3.0 mg is recommended as a treatment option for weight management in adults who meet specific criteria. Patients must have a body mass index (BMI) of 35 kg/m² or greater, or a BMI of 32.5 kg/m² or greater for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean family backgrounds. Eligible patients must also have at least one weight-related comorbidity such as hypertension, type 2 diabetes, dyslipidaemia, obstructive sleep apnoea, or non-alcoholic fatty liver disease. Additional criteria include the presence of non-diabetic hyperglycaemia and high cardiovascular risk.

Liraglutide must be prescribed within a specialist tier 3 weight management service that provides multidisciplinary support, including dietary advice, physical activity programmes, and behavioural interventions. Before initiating liraglutide, patients should have attempted weight loss through a structured, supervised programme for at least six months without achieving adequate results. Under NICE TA664, NHS-funded treatment is normally provided for a maximum of 2 years.

Treatment response should be assessed 16 weeks after initiation (or after 12 weeks on the 3.0 mg dose). Treatment should only be continued if the patient has lost at least 5% of their initial body weight, demonstrating a therapeutic response. This stopping rule ensures that resources are directed towards those who benefit from the medication.

Liraglutide is also licensed in the UK for adolescents aged 12–17 years with obesity (initial body weight above 60 kg), used under specialist supervision within appropriate weight management services.

Contraindications and cautions include:

• Personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (liraglutide is not recommended in these patients)

• Pregnancy and breastfeeding (adequate contraception required in women of childbearing potential)

• Severe renal or hepatic impairment

• Severe gastrointestinal disease including diabetic gastroparesis

• Age over 75 years (limited safety data)

A thorough medical assessment, including baseline weight and BMI, screening for comorbidities and contraindications, and pregnancy status in women of childbearing potential, should precede treatment initiation. Clinician-directed baseline investigations (such as relevant blood tests) may be appropriate depending on individual circumstances, but routine thyroid function testing is not required. Patients must be willing to engage with ongoing lifestyle modification and regular monitoring throughout the treatment course.

References: NICE TA664: Liraglutide for managing overweight and obesity; EMC SmPC: Saxenda (liraglutide) 6 mg/mL solution for injection; BNF: liraglutide (Saxenda) entry; NHS guidance on specialist weight management (tier 3) services.

Expected Weight Loss Results and Treatment Duration

Clinical trial data from the SCALE (Satiety and Clinical Adiposity – Liraglutide Evidence) programme provide robust evidence for liraglutide's efficacy in obesity management. In the pivotal SCALE Obesity and Prediabetes trial, participants receiving liraglutide 3.0 mg alongside lifestyle intervention achieved an average weight loss of 8.0% of initial body weight at 56 weeks, compared to 2.6% in the placebo group. Approximately 63% of liraglutide-treated patients lost at least 5% of body weight, and 33% achieved losses exceeding 10%.

Weight loss typically begins within the first few weeks of treatment, with the most substantial reductions occurring during the first six months. Treatment response should be assessed 16 weeks after starting liraglutide (or after 12 weeks on the 3.0 mg dose). Patients who have not lost at least 5% of their starting weight at this assessment point are unlikely to achieve clinically meaningful results with continued therapy and should discontinue treatment. For responders, weight loss generally plateaus between six and twelve months, after which weight maintenance becomes the primary goal.

Under NICE TA664, NHS-funded treatment is provided within a specialist tier 3 weight management service and is normally limited to a maximum of 2 years. Treatment duration varies according to individual response and clinical need. Annual review is recommended, considering discontinuation if weight loss is not maintained or if the patient no longer meets the criteria for treatment. Some patients may require longer-term therapy to sustain weight loss, whilst others may successfully transition to weight maintenance through lifestyle measures alone. Real-world evidence suggests that weight regain commonly occurs following liraglutide discontinuation, highlighting the importance of establishing sustainable behavioural changes during treatment.

Factors influencing treatment success include:

• Adherence to daily injections and dose titration schedule

• Concurrent engagement with dietary and physical activity programmes

• Management of side effects, particularly gastrointestinal symptoms

• Psychological support and motivation throughout the treatment journey

References: Pi-Sunyer et al., N Engl J Med 2015 (SCALE Obesity and Prediabetes); NICE TA664: Liraglutide for managing overweight and obesity; EMC SmPC: Saxenda (liraglutide).

Side Effects and Safety Considerations

Gastrointestinal adverse effects are the most commonly reported side effects of liraglutide, affecting the majority of patients to some degree. Nausea is particularly prevalent, occurring in approximately 40% of users, especially during dose escalation. Other frequent gastrointestinal symptoms include vomiting, diarrhoea, constipation, and abdominal discomfort. These effects are usually transient and diminish over several weeks as tolerance develops. The gradual dose titration protocol (starting at 0.6 mg daily and increasing by 0.6 mg weekly increments to the target 3.0 mg dose) is specifically designed to minimise these symptoms.

More serious but less common adverse effects require clinical vigilance. Acute pancreatitis has been reported in post-marketing surveillance, though a definitive causal relationship remains uncertain. Patients should be advised to seek immediate medical attention if they experience severe, persistent abdominal pain radiating to the back, particularly if accompanied by vomiting. Liraglutide should be discontinued if pancreatitis is suspected and not restarted if confirmed.

Gallbladder disorders, including cholelithiasis and cholecystitis, occur more frequently with liraglutide than placebo, likely related to rapid weight loss rather than direct drug toxicity. Patients should be counselled about symptoms of biliary colic and cholecystitis.

Based on rodent studies, there is a theoretical risk of thyroid C-cell tumours, though no increased risk has been demonstrated in humans. Nevertheless, liraglutide is not recommended in patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. Patients should be monitored for symptoms of thyroid tumours (e.g., a lump in the neck, persistent hoarseness, difficulty swallowing, or shortness of breath).

Rare hypersensitivity reactions, including anaphylaxis and angioedema, have been reported. Patients should seek immediate medical attention if they experience symptoms such as swelling of the face, lips, tongue, or throat, difficulty breathing, or severe rash.

The MHRA is reviewing reports of suicidal ideation and self-harm associated with GLP-1 receptor agonists. Patients should be counselled to seek urgent medical advice if they experience new or worsening mood changes, depression, or thoughts of self-harm.

Other notable considerations include:

• Hypoglycaemia risk is low when used as monotherapy but increases if combined with insulin or sulphonylureas in diabetic patients

• Injection site reactions (erythema, pruritus) are usually mild and self-limiting

• Increased heart rate (average 2–3 beats per minute elevation) requires monitoring in patients with cardiovascular disease

• Renal function should be monitored, particularly in patients experiencing severe gastrointestinal symptoms leading to dehydration

Patients should contact their GP promptly if they experience persistent vomiting, severe abdominal pain, signs of dehydration, or any symptoms causing significant concern.

Reporting side effects: Patients and healthcare professionals are encouraged to report suspected adverse drug reactions via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or through the Yellow Card app.

References: EMC SmPC: Saxenda (liraglutide) – adverse reactions; MHRA/EMA communications on GLP-1 RAs and suicidal ideation (safety review updates).

NHS Availability and Private Prescription Options

NHS availability of liraglutide for obesity treatment varies considerably across the UK due to local commissioning decisions and funding constraints. Whilst NICE has recommended liraglutide as a treatment option for eligible patients (TA664), many Integrated Care Boards (ICBs) in England and equivalent bodies in Scotland, Wales, and Northern Ireland have implemented restrictive prescribing policies or declined to commission the treatment due to cost considerations. The annual cost of liraglutide 3.0 mg typically exceeds £2,000 per patient (BNF list price), making it one of the more expensive pharmacological options for weight management.

Under NICE TA664, liraglutide must be prescribed within a specialist tier 3 weight management service, which provides multidisciplinary support including dietetic input, physical activity advice, and psychological interventions. NHS-funded treatment is normally limited to a maximum of 2 years. Referral criteria are stringent, and waiting times can be substantial. Some areas may operate shared-care protocols allowing GPs to prescribe under specialist supervision once treatment is established, though this depends on local ICB policy and specialist initiation and oversight. Patients should enquire with their GP practice about local commissioning arrangements and referral pathways.

Private prescription options are widely available through various routes:

• Private hospital weight management clinics offering comprehensive assessment and ongoing monitoring

• Specialist private GP services focusing on obesity medicine

• Online prescribing services (patients should ensure these are regulated by the Care Quality Commission in England, Healthcare Improvement Scotland, Healthcare Inspectorate Wales, or the Regulation and Quality Improvement Authority in Northern Ireland, and that dispensing pharmacies are registered with the General Pharmaceutical Council)

• Private endocrinology or diabetes consultants

Private treatment costs include initial consultation fees (typically £150–300), ongoing prescription costs (approximately £150–200 monthly for medication, though costs vary by provider and dose), and follow-up appointments. Patients pursuing private treatment should ensure they receive proper medical assessment, regular monitoring, and integration with lifestyle modification programmes rather than medication alone.

Regardless of funding route, successful obesity treatment with liraglutide requires commitment to long-term lifestyle changes, regular clinical review, and realistic expectations about weight loss outcomes. Patients should discuss both NHS and private options with their GP to determine the most appropriate pathway for their individual circumstances.

References: NICE TA664 implementation notes; BNF (pricing/availability notes); NHS England/ICB commissioning policies for obesity pharmacotherapy.

Frequently Asked Questions