Liraglutide
The first long-acting GLP-1 receptor agonist approved for obesity, a once-daily injection that reduces appetite and blood sugar.
Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist approved for chronic weight management (Saxenda, 3.0 mg) and type 2 diabetes (Victoza, up to 1.8 mg), administered as a daily subcutaneous injection. It mimics the incretin hormone GLP-1 to slow gastric emptying, increase satiety, and stimulate glucose-dependent insulin secretion, producing roughly 6-8% mean weight loss in the SCALE trials. As the molecule that proved the GLP-1 mechanism in humans, it laid the groundwork for semaglutide and tirzepatide, which now outperform it, leaving liraglutide's practical role centered on pediatric obesity, insurance-driven access, and its long safety record.
Class
31-amino-acid GLP-1 receptor agonist (acylated peptide analog)
Half-life
~13 hours
Routes
Subcutaneous injection
Category
Weight Loss & Metabolic
Researched benefits
What it's studied for
Meaningful weight loss
The SCALE Obesity and Prediabetes trial showed a mean 8.0-8.4% body-weight reduction at 3.0 mg daily over 56 weeks, with 63.2% of participants achieving at least 5% weight loss. The effect is real and clinically meaningful, though smaller than semaglutide or tirzepatide.
Appetite suppression and satiety
By activating GLP-1 receptors in the hypothalamus and brainstem, liraglutide increases satiety signaling and slows gastric emptying, reducing caloric intake through both central and peripheral pathways.
Blood sugar regulation
As approved for type 2 diabetes (Victoza), it stimulates glucose-dependent insulin secretion and suppresses glucagon, lowering blood glucose with low intrinsic hypoglycemia risk.
Cardiovascular risk reduction
The LEADER trial demonstrated a roughly 13% relative reduction in major adverse cardiovascular events (MACE) among type 2 diabetes patients with high cardiovascular risk, adding an outcomes benefit beyond glucose control.
Pediatric and adolescent efficacy
Liraglutide was the first GLP-1 approved for pediatric obesity in adolescents 12-17 (2020), with a trial (n=251) showing efficacy, and newer data extending into children 6-12 giving it the deepest pediatric outcome record in the class.
Multisystem metabolic benefits
Review-level evidence associates liraglutide and other GLP-1 agonists with improvements beyond weight loss, including metabolic liver disease, sleep apnea, and depression, with growing evidence for weight-independent receptor-mediated effects.
Mechanism
How it works
Liraglutide is a structural analog of native glucagon-like peptide-1 (GLP-1). A single amino acid substitution (Lys34Arg) plus the attachment of a C16 fatty-acid chain at position 26 allows it to bind albumin and resist DPP-4 degradation, extending the half-life from native GLP-1's roughly 2 minutes to about 13 hours. This still requires once-daily subcutaneous dosing, in contrast to semaglutide's albumin-binding modification that stretches its half-life to about 7 days for weekly administration.
As a GLP-1 receptor agonist, it reproduces the full incretin pharmacology: it slows gastric emptying, increases satiety, stimulates glucose-dependent insulin secretion, and suppresses glucagon. The appetite-suppressing effect is driven largely by GLP-1 receptors in the hypothalamus and brainstem, which reduce hunger and caloric intake.
The combined peripheral and central actions lower food intake and improve glycemic control. In diabetes this manifests as reduced blood glucose; in obesity it produces sustained caloric deficit and weight loss. The shorter half-life relative to newer agents is the primary reason liraglutide delivers smaller weight-loss magnitudes than weekly GLP-1 and dual/triple agonists.
Dosing protocols
Dosing & administration
Dosing reflects protocols reported in research and community literature for educational purposes. It is not medical advice or a recommendation. Most peptides here are not approved for human use.
Weight management (Saxenda) — titration
- Dose
- Start 0.6 mg/day, increase in 0.6 mg increments weekly
- Frequency
- Once daily
- Timing
- Same time each day, independent of meals
- Duration
- Over 4-5 weeks to reach maintenance
- Route
- Subcutaneous
Gradual titration reduces gastrointestinal side effects. Do not advance if a dose is poorly tolerated.
Weight management (Saxenda) — maintenance
- Dose
- 3.0 mg/day
- Frequency
- Once daily
- Timing
- Same time each day
- Duration
- Ongoing while benefit continues
- Route
- Subcutaneous
Full maintenance dose for chronic weight management; weight tends to return if discontinued.
Type 2 diabetes (Victoza)
- Dose
- 1.2-1.8 mg/day (start 0.6 mg for one week)
- Frequency
- Once daily
- Timing
- Same time each day
- Duration
- Ongoing
- Route
- Subcutaneous
Lower dosing range than the obesity indication; 0.6 mg starting week is for tolerability, not therapeutic effect.
- Liraglutide is supplied as a branded/generic prefilled multi-dose pen, not typically reconstituted by the user.
- Daily injection is the key practical difference from weekly GLP-1 agonists and is associated with lower adherence.
- All dosing should be established and supervised by a licensed prescriber.
- Rotate injection sites (abdomen, thigh, upper arm) to reduce local reactions.
Evidence
Research & clinical studies (12)
Semaglutide vs liraglutide for weight loss in adults with overweight or obesity (STEP 8)
Once-weekly semaglutide 2.4 mg reduced mean body weight by 15.8% versus 6.4% for once-daily liraglutide 3.0 mg over 68 weeks (n=338), providing direct head-to-head comparative evidence.
PMID 35015037A randomized, controlled trial of 3.0 mg of liraglutide in weight management (SCALE Obesity and Prediabetes)
Liraglutide 3.0 mg daily reduced mean body weight by 8.4 kg versus 2.8 kg for placebo over 56 weeks (n=3,731), with 63.2% of participants achieving at least 5% weight loss.
PMID 26132939Comparative Effects of Individual GLP-1 Receptor Agonist-Based Medications on Direct Measurement of Body Composition: A Systematic Review and Network Meta-Analysis
GLP-1 receptor agonists including liraglutide effectively reduced body fat but also produced reductions in lean mass that were most pronounced at higher doses.
PMID 42209204GLP-1 receptor agonists for weight management and potential thromboembolic risk reduction in high-risk populations with cancer, diabetes, cardiovascular disease: A systematic review
GLP-1 agonists including liraglutide produced substantial weight loss and cardiovascular risk reduction in high-risk populations, though direct evidence for thromboembolic event reduction remains limited.
PMID 42215399Evaluation of the safety profile of GLP-1 receptor agonists: a focus on thyroid cancer-related adverse events using the European pharmacovigilance database
Gastrointestinal and general disorders were the most commonly reported adverse events across GLP-1 agonists, mostly in adult and elderly female patients; thyroid cancer signal findings required cautious interpretation.
PMID 42207473Beyond weight loss: multisystem benefits of obesity medications
Liraglutide and other GLP-1 agonists produce clinically meaningful multisystem benefits beyond weight loss, including improvements in T2D, cardiovascular disease, metabolic liver disease, sleep apnoea, and depression.
PMID 42208956GLPs Significantly Decrease the Risk of Postoperative Surgical Complications: A TriNetX Retrospective Cohort Study
Patients taking GLP receptor agonists had significantly reduced rates of postoperative inflammatory complications within one month of dermatologic surgery.
PMID 42210885GLP-1 receptor agonists in pediatric obesity and diabetes: a systematic review of efficacy, metabolic effects, and safety
Systematic review supporting the efficacy, metabolic effects, and safety of GLP-1 receptor agonists in pediatric obesity and diabetes.
PMID 42365860Effects of the GLP-1 receptor agonist liraglutide on bupivacaine-induced sciatic nerve block in a rat model
Examined liraglutide's effects on bupivacaine-induced sciatic nerve block in a rat model.
PMID 42377486Effects of the GLP-1 receptor agonist liraglutide on retinal endothelial function and oxidative stress during sepsis
Investigated liraglutide's effects on retinal endothelial function and oxidative stress in a sepsis model.
PMID 42375616GLP-1 Receptor Agonists and the Ocular Surface: A Narrative Review of Restoration, Remodeling, and Clinical Implications
Narrative review of GLP-1 receptor agonist effects on the ocular surface, including restoration and remodeling implications.
PMID 42366332HNF1B-MODY (MODY-5): a rare form of diabetes with multisystemic features - two case reports
Reported that HNF1B-MODY presents with multisystemic features beyond diabetes and that early genetic confirmation is essential for management.
PMID 42369057Safety
Side effects & considerations
Commonly reported effects
Contraindications & cautions
- Personal or family history of medullary thyroid carcinoma
- MEN 2 syndrome
- History of pancreatitis
- Pregnancy
Gastrointestinal effects are the most common and are typically milder than semaglutide, though daily dosing means daily exposure. Liraglutide carries the class-wide boxed warning for thyroid C-cell tumors based on rodent studies. Requires physician supervision. This is educational information only, not medical advice.
FAQ
Liraglutide — common questions
What is liraglutide?
Liraglutide is a once-daily GLP-1 receptor agonist and the first long-acting GLP-1 to reach market. It is FDA-approved as Victoza (2010, type 2 diabetes) and Saxenda (2014, chronic weight management), and works by activating GLP-1 receptors in the hypothalamus and brainstem to reduce appetite.
How much weight loss does liraglutide produce?
The SCALE Obesity and Prediabetes trial showed a mean weight loss of approximately 8% of body weight at 3.0 mg daily over 56 weeks. This is meaningful but more modest than semaglutide (about 15% in STEP trials) or tirzepatide, largely due to its shorter half-life and daily dosing.
How is liraglutide administered?
As a once-daily subcutaneous injection. For weight management (Saxenda), dosing starts at 0.6 mg/day and titrates over 4-5 weeks to a maintenance dose of 3.0 mg/day. For type 2 diabetes (Victoza) the maintenance range is lower, typically 1.2-1.8 mg/day.
How does liraglutide compare to semaglutide?
Liraglutide is daily; semaglutide is weekly, reflecting half-lives of about 13 hours versus about 7 days. In the STEP 8 head-to-head, semaglutide 2.4 mg produced 15.8% weight loss versus liraglutide 3.0 mg's 6.4% over 68 weeks. Liraglutide's remaining advantages are pediatric data, insurance access pathways, and a longer safety record.
What are the side effects of liraglutide?
The most common are gastrointestinal: nausea, vomiting, diarrhea, and constipation, generally milder than semaglutide. It carries a boxed warning for thyroid C-cell tumors and is contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN 2 syndrome, and in pregnancy or with a history of pancreatitis.
Is liraglutide FDA approved?
Yes. It is FDA-approved as Victoza (2010, type 2 diabetes) and Saxenda (2014, chronic weight management). Generic liraglutide began reaching the US market in 2024-2025.
How much does liraglutide cost?
Branded Saxenda has historically retailed around $1,300-$1,500 per month without insurance, and Victoza is similarly priced. Generic versions launched in 2024-2025 have lowered prices, though absolute cost still often sits above weekly branded competitors under common insurance pathways.
Is liraglutide still relevant given newer GLP-1 drugs?
For adult weight loss it has largely been displaced by weekly semaglutide and tirzepatide, which are more effective and more convenient. Its continued relevance is in pediatric obesity (where it has the deepest data), insurance-driven access, documented cardiovascular benefit, and patients who tolerate it but not the weekly drugs.
