At a Glance
| Feature | Detail |
|---|---|
| Class / structure | Acylated GLP-1 analogue: human GLP-1 (7-37) with a Lys34Arg substitution and a C16 palmitic acid chain attached via a glutamic acid spacer at Lys26 — 97% homology to native GLP-1 |
| Origin | Developed at Novo Nordisk from the acylated GLP-1 series described by Knudsen in 2000 |
| Mechanism | GLP-1 receptor agonist: glucose-dependent insulin secretion, glucagon suppression, slowed gastric emptying, hypothalamic appetite suppression |
| Used for | Type 2 diabetes (Victoza), chronic weight management (Saxenda), cardiovascular risk reduction in T2D |
| Route | Once-daily subcutaneous injection (abdomen, thigh or upper arm) |
| Typical dose range | 0.6–1.8 mg daily (diabetes); 0.6–3.0 mg daily (weight management) |
| Half-life | ~13 hours (albumin binding plus DPP-4 resistance) |
| Evidence level | Strong — the SCALE programme (four large randomised trials), the LEADER cardiovascular outcome trial, a paediatric randomised trial, and a head-to-head against semaglutide |
| Regulatory status | FDA approved (Victoza 2010, Saxenda 2014; first generic approved and launched August 2025). EMA approved. Prescription-only in Germany |
| Anti-doping (WADA 2026) | GLP-1 receptor agonists are not prohibited as a class; verify the current list before competition |
Liraglutide is the drug that proved the category. Before Saxenda’s approval in 2014, pharmacological weight loss meant single-digit percentages from agents with unattractive safety profiles. Liraglutide delivered a reproducible 8% mean weight loss in a 3,731-person trial, then showed cardiovascular benefit in diabetes — and established that incretin receptor agonism was a serious therapeutic strategy rather than an appetite-suppressant footnote.
The honest verdict in 2026: liraglutide is a well-characterised, genuinely effective drug that newer agents clearly outperform on the thing patients care about most. Weekly semaglutide roughly doubles its weight loss; tirzepatide roughly triples it. What liraglutide still has is the longest safety record in the class, a generic price, paediatric approval from age 12, and a short half-life that is occasionally a feature rather than a bug.
It is also the best-documented example of something worth understanding before starting any drug in this class: when treatment stops, the weight comes back.
How it works
Liraglutide is native GLP-1 with two modifications: a single amino acid substitution and a palmitic acid side chain. The fatty acid binds reversibly to serum albumin, which both shields the molecule from dipeptidyl peptidase-4 and slows absorption from the injection site. Half-life goes from roughly two minutes for the native hormone to about thirteen hours — enough for once-daily dosing [1].
Receptor pharmacology is unchanged. Liraglutide activates the same GLP-1 receptor and produces the same four effects: glucose-dependent insulin secretion, glucagon suppression, delayed gastric emptying, and central appetite suppression through hypothalamic and brainstem GLP-1 receptors [9]. The weight effect is predominantly reduced energy intake; the glycaemic effect combines improved insulin secretion with reduced hepatic glucose output.
Two consequences of the thirteen-hour half-life matter in practice. Plasma levels fluctuate within each day, so appetite suppression is less flat than with weekly agents — some people describe hunger returning in the late afternoon. And if the drug has to be stopped quickly, for surgery or for intolerable nausea, it clears in a day or two rather than over weeks.
What the evidence shows
Weight loss: the SCALE programme
SCALE Obesity and Prediabetes (Pi-Sunyer, NEJM 2015) randomised 3,731 adults without diabetes, mean weight 106.2 kg, mean BMI 38.3, to liraglutide 3.0 mg daily or placebo for 56 weeks. Mean weight loss was 8.4 kg with liraglutide versus 2.8 kg with placebo (difference −5.6 kg). 63.2% versus 27.1% lost at least 5% of body weight; 33.1% versus 10.6% lost more than 10%. Serious adverse events occurred in 6.2% versus 5.0% [2].
SCALE Diabetes (Davies, JAMA 2015) studied adults with type 2 diabetes. Weight loss was 6.0% (6.4 kg) on 3.0 mg, 4.7% (5.0 kg) on 1.8 mg and 2.0% (2.2 kg) on placebo; at least 5% weight loss occurred in 54.3%, 40.4% and 21.4% respectively [3]. The consistent finding across this class is that weight loss in diabetes is smaller than in obesity without diabetes — worth saying out loud, because headline figures usually come from the non-diabetic trials.
SCALE Maintenance (Wadden, Int J Obes 2013) asked a different question: can liraglutide hold a diet-induced loss? After 422 participants lost a mean 6.0% on a low-calorie diet, liraglutide produced a further 6.2% loss versus 0.2% on placebo over 56 weeks, and 81.4% versus 48.9% maintained the run-in loss [4].
Three-year data (le Roux, Lancet 2017) followed 2,254 adults with prediabetes for 160 weeks. Time to diabetes onset was 2.7 times longer with liraglutide (HR 0.21), with 2% versus 6% diagnosed with diabetes while on treatment, and weight loss of 6.1% versus 1.9% at week 160 [5]. This is the longest randomised weight-management dataset for the drug.
Adolescents (Kelly, NEJM 2020) randomised 251 adolescents with obesity. Liraglutide 3.0 mg produced a greater reduction in BMI standard-deviation score than placebo (estimated difference −0.22; P = 0.002), with 43.3% versus 18.7% achieving at least a 5% BMI reduction. After discontinuation, BMI z-score rose again more in the liraglutide group [6] — the clearest published demonstration of weight regain on stopping.
Cardiovascular outcomes: LEADER
LEADER (Marso, NEJM 2016) randomised 9,340 people with type 2 diabetes at high cardiovascular risk, median follow-up 3.8 years. The primary composite of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke occurred in 13.0% on liraglutide versus 14.9% on placebo (HR 0.87, 95% CI 0.78–0.97; P = 0.01 for superiority). Cardiovascular death was lower (4.7% vs 6.0%, HR 0.78) and all-cause death was lower (8.2% vs 9.6%, HR 0.85). Gastrointestinal events were the commonest reason for discontinuation [7].
LEADER is a diabetes trial. It does not establish cardiovascular benefit for liraglutide in obesity without diabetes — that evidence exists for semaglutide (SELECT), not for liraglutide.
Head to head against semaglutide
STEP 8 (Rubino, JAMA 2022) randomised 338 adults to weekly semaglutide 2.4 mg or daily liraglutide 3.0 mg for 68 weeks. Mean weight change was −15.8% with semaglutide versus −6.4% with liraglutide (difference −9.4 percentage points, 95% CI −12.0 to −6.8); 70.9% versus 25.6% achieved at least 10% loss [8]. This is the trial that moved liraglutide from first-line to second-line for weight management in most practices, and it is why I would not start liraglutide for weight loss in someone who can access and afford a weekly agent.
Dosing
For informational purposes only — this summarises doses used in research and practice; it is not a prescription or individual medical advice.
| Goal | Dose | Route | Frequency / timing | Cycle length | Basis |
|---|---|---|---|---|---|
| Weight management (BMI ≥30, or ≥27 with a comorbidity) | 0.6 mg week 1 → 1.2 → 1.8 → 2.4 → 3.0 mg from week 5 | SC (abdomen, thigh, upper arm) | Once daily, any time, with or without food | Indefinite maintenance; reassess at 16 weeks | Label (Saxenda) + Trial — Pi-Sunyer 2015, PMID 26132939 |
| Type 2 diabetes | 0.6 mg for ≥1 week → 1.2 mg → 1.8 mg if needed | SC | Once daily | Indefinite | Label (Victoza) + Trial — Marso 2016, PMID 27295427 |
| Adolescents 12–17 with obesity | Same escalation to 3.0 mg or maximum tolerated | SC | Once daily | Indefinite | Trial — Kelly 2020, PMID 32233338; label |
| Holding a diet-induced weight loss | 3.0 mg | SC | Once daily | 56 weeks studied | Trial — Wadden 2013, PMID 23812094 |
| Nausea-limited titration | Hold each step 2–4 weeks instead of 1; maintain at 1.8 or 2.4 mg if 3.0 mg is not tolerated | SC | Once daily | Indefinite | Practice protocol — standard in obesity-medicine practice; SCALE Diabetes shows 1.8 mg retains ~4.7% weight loss [3] |
The 16-week rule, which is on the label and worth keeping. If a patient has not lost at least 4% of body weight after 16 weeks at the maintenance dose, continuing rarely pays off. Switch rather than persist.
Timing. A fixed daily time is easier to sustain than “whenever”. Many people prefer the evening so that peak nausea falls during sleep. If doses are missed for more than a day or two and nausea was an issue, resume at the last comfortably tolerated step rather than at 3.0 mg.
Stacks and combinations commonly used.
- Protein intake of roughly 1.6–2.2 g/kg ideal body weight plus resistance training — not a drug, but the intervention that most changes the outcome. Lean-mass loss is the main body-composition cost in this class; the protocol is set out in preserving muscle on GLP-1 therapy.
- Metformin: standard, additive on glycaemia, no dose adjustment needed. See metformin for longevity.
- Insulin or sulfonylureas: reduce those agents before escalating liraglutide. This is where hypoglycaemia actually happens.
- Injection technique, site rotation and needle choice are covered in the peptide injection guide.
What people report: what works and what doesn’t
Sources: the randomised trials above, plus the open community record on r/liraglutide and r/Saxenda, and published obesity-medicine practice guidance. Community material shows patterns, not proof; no individual account is treated as evidence.
Reported to work
- Appetite suppression starting within the first few days, well before meaningful weight change. The trial data support the mechanism: the effect is on energy intake.
- Reduction of “food noise” — intrusive thoughts about eating. Not a trial endpoint, consistently described across the whole class.
- Weight loss in the 5–10% range over the first year, which matches SCALE closely. People expecting semaglutide-scale results from liraglutide are routinely disappointed; people expecting SCALE-scale results usually are not.
- Nausea improving substantially once titration is finished.
Mixed or unclear
- Whether shifting the time of the daily dose reduces nausea. Over a 13-hour half-life this should matter little, and reports go both ways.
- Appetite “wearing off” late in the day. Plausible given daily pharmacokinetics; not an established trial finding.
- Staying at 1.8 mg versus pushing to 3.0 mg. SCALE Diabetes suggests 1.8 mg retains most but not all of the effect [3], and many people stay there for tolerability.
- Hair shedding and gallbladder symptoms: both are reported and both appear in trial safety data, but they track rapid weight loss as much as the drug itself.
Reported not to work / disappointing
- Weight maintenance after stopping. This is the dominant disappointment, and the trials agree that regain is the expected course [5, 6].
- Matching weekly agents. STEP 8 quantified the gap at roughly 9 percentage points [8].
- Pushing through severe nausea by holding 3.0 mg. Practice protocols step back down instead, and tolerability-driven dose reduction is common.
- Daily-injection fatigue and injection-site reactions are the practical reasons people switch to a weekly drug even when liraglutide is working.
What a properly designed trial would still need to show: whether liraglutide reduces cardiovascular events in obesity without diabetes. SELECT answered that question for semaglutide; the equivalent trial for liraglutide was never run, and now never will be.
Safety and side effects
Common. Nausea (the dose-limiting effect in most patients), vomiting, diarrhoea, constipation, dyspepsia, headache, fatigue, injection-site reactions. Gastrointestinal effects cluster during escalation and improve with time.
Serious but uncommon. Acute pancreatitis (stop and do not restart if confirmed); gallstone disease and cholecystitis, more frequent with faster weight loss; acute kidney injury in the context of volume depletion from vomiting or diarrhoea; hypersensitivity reactions. Rodent studies showed thyroid C-cell tumours, which is why the label carries a boxed warning; human registry data have not confirmed a signal, but the contraindication stands.
Contraindications. Personal or family history of medullary thyroid carcinoma, MEN2, prior hypersensitivity to liraglutide, pregnancy and breastfeeding. Avoid with a history of pancreatitis and in severe gastroparesis.
Interactions. Delayed gastric emptying can alter the absorption rate of oral drugs, which matters most for narrow-therapeutic-index medicines. Combination with insulin or sulfonylureas requires pre-emptive dose reduction of those agents.
Monitoring I would want. Weight and waist circumference, HbA1c and fasting glucose, renal function, lipids, and a symptom check for gallbladder and pancreatic pain. In anyone at risk of sarcopenia, a body-composition measure rather than weight alone.
Sourcing. Liraglutide is a prescription medicine with an approved generic. There is no reason to buy it from a research-chemical vendor, and compounded “liraglutide” products carry the identity and sterility risks described in peptide sourcing.
Legal and regulatory status
United States. FDA approved: Victoza (2010) for type 2 diabetes, Saxenda (2014) for chronic weight management, with a paediatric indication from age 12. The first generic liraglutide injection was approved and launched in August 2025 — the single biggest practical change for access in this category, because it puts an effective GLP-1 at generic pricing for the first time.
European Union and Germany. EMA approved for both indications; prescription-only (verschreibungspflichtig). Reimbursement for weight management remains restrictive in Germany, where obesity pharmacotherapy is generally treated as a Lifestyle-Arzneimittel and paid privately.
Sport. GLP-1 receptor agonists are not currently on the WADA prohibited list as a class. Athletes should check the current list each season — the status of metabolic agents has been revisited more than once. See peptides and WADA rules.
How it fits: where a daily GLP-1 still makes sense
| Liraglutide 3.0 mg | Semaglutide 2.4 mg | Tirzepatide 15 mg | |
|---|---|---|---|
| Dosing | Daily | Weekly | Weekly |
| Trial weight loss | 8.4 kg / ~8% (56 wk) | ~15% (68 wk) | ~21% (72 wk) |
| Head-to-head | Reference | −15.8% vs −6.4% (STEP 8) | −20.2% vs −13.7% vs semaglutide (SURMOUNT-5) |
| CV outcome data | T2D (LEADER) | T2D and obesity (SELECT) | T2D (SURPASS-CVOT) |
| Approved from age 12 | Yes | Yes (Wegovy) | No |
| Generic available | Yes (US, 2025) | No | No |
| Half-life | ~13 h | ~7 days | ~5 days |
Liraglutide is now a second-line choice for weight, with three situations where I would still reach for it: cost or coverage puts the weekly agents out of reach; the patient needs a drug that clears quickly, for example before planned surgery or after severe GI intolerance; or the patient specifically wants the agent with the longest real-world safety record. For diabetes with established cardiovascular disease the question has become which GLP-1 rather than whether — and semaglutide’s and tirzepatide’s outcome data have moved ahead.
It is worth remembering what liraglutide did for the field. SCALE and LEADER established that this receptor is worth targeting, that the weight loss is real, and that the benefit is maintenance-dependent. Every drug in the comparison table above inherited that framework.
Related Articles
- Native GLP-1 (7-36 Amide): Why “Pure GLP-1” Fails as a Drug — the hormone liraglutide was engineered from.
- Semaglutide: Beyond Weight Loss — A Physician’s Assessment — the agent that superseded it on weight.
- Tirzepatide: The Dual GIP/GLP-1 Agonist in Full — current first-line for depth of weight loss.
- Preserving Muscle on Semaglutide and Tirzepatide — the protein and training protocol, which applies equally to liraglutide.
- Berberine vs Semaglutide: What the Evidence Actually Shows — for patients asking about non-prescription options.
- GLP-1 Drugs and Aging: Outcome Trials vs the Longevity Hype — what the outcome data do and do not support.
Frequently asked questions
How much weight do people lose on liraglutide 3.0 mg?
In SCALE Obesity (3,731 adults, 56 weeks), mean weight loss was 8.4 kg on liraglutide 3.0 mg versus 2.8 kg on placebo; 63% lost at least 5% of body weight and 33% lost more than 10%. In people with type 2 diabetes (SCALE Diabetes) the figure was smaller: 6.0% of body weight versus 2.0% on placebo.
Is liraglutide better than semaglutide?
Not for weight. STEP 8 compared them head to head: −15.8% with weekly semaglutide 2.4 mg versus −6.4% with daily liraglutide 3.0 mg over 68 weeks. Liraglutide's remaining advantages are cost (a US generic launched in August 2025), the longest post-marketing record in the class, and approval from age 12.
What is the difference between Saxenda and Victoza?
Same molecule, different dose and indication. Victoza is approved for type 2 diabetes at up to 1.8 mg daily; Saxenda is approved for weight management at up to 3.0 mg daily. Both are once-daily subcutaneous injections.
How is liraglutide titrated?
For weight management, 0.6 mg daily in week one, then an increase of 0.6 mg each week to 3.0 mg by week five. For diabetes, 0.6 mg for at least one week, then 1.2 mg, then 1.8 mg if needed. Slower escalation is commonly used when nausea is limiting.
Does liraglutide reduce cardiovascular risk?
In LEADER (9,340 people with type 2 diabetes at high cardiovascular risk, median 3.8 years), the primary composite endpoint occurred in 13.0% on liraglutide versus 14.9% on placebo (HR 0.87), with lower cardiovascular and all-cause mortality. That evidence is in diabetes, not in obesity without diabetes.
What happens when you stop liraglutide?
Weight returns. In the adolescent trial, BMI z-score rose again after discontinuation, and the three-year prediabetes trial showed the same pattern in adults. Obesity pharmacotherapy is maintenance treatment, not a course.
References
- Knudsen LB, et al. Potent derivatives of glucagon-like peptide-1 with pharmacokinetic properties suitable for once daily administration. J Med Chem. 2000;43(9):1664-9. PMID: 10794683. https://pubmed.ncbi.nlm.nih.gov/10794683/
- Pi-Sunyer X, et al. A randomized, controlled trial of 3.0 mg of liraglutide in weight management. N Engl J Med. 2015;373(1):11-22. PMID: 26132939. https://pubmed.ncbi.nlm.nih.gov/26132939/
- Davies MJ, et al. Efficacy of liraglutide for weight loss among patients with type 2 diabetes: the SCALE Diabetes randomized clinical trial. JAMA. 2015;314(7):687-99. PMID: 26284720. https://pubmed.ncbi.nlm.nih.gov/26284720/
- Wadden TA, et al. Weight maintenance and additional weight loss with liraglutide after low-calorie-diet-induced weight loss: the SCALE Maintenance randomized study. Int J Obes (Lond). 2013;37(11):1443-51. PMID: 23812094. https://pubmed.ncbi.nlm.nih.gov/23812094/
- le Roux CW, et al. 3 years of liraglutide versus placebo for type 2 diabetes risk reduction and weight management in individuals with prediabetes: a randomised, double-blind trial. Lancet. 2017;389(10077):1399-1409. PMID: 28237263. https://pubmed.ncbi.nlm.nih.gov/28237263/
- Kelly AS, et al. A randomized, controlled trial of liraglutide for adolescents with obesity. N Engl J Med. 2020;382(22):2117-28. PMID: 32233338. https://pubmed.ncbi.nlm.nih.gov/32233338/
- Marso SP, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes. N Engl J Med. 2016;375(4):311-22. PMID: 27295427. https://pubmed.ncbi.nlm.nih.gov/27295427/
- Rubino DM, et al. Effect of weekly subcutaneous semaglutide vs daily liraglutide on body weight in adults with overweight or obesity without diabetes: the STEP 8 randomized clinical trial. JAMA. 2022;327(2):138-50. PMID: 35015037. https://pubmed.ncbi.nlm.nih.gov/35015037/
- Holst JJ. The physiology of glucagon-like peptide 1. Physiol Rev. 2007;87(4):1409-39. PMID: 17928588. https://pubmed.ncbi.nlm.nih.gov/17928588/
- World Anti-Doping Agency. The 2026 Prohibited List, valid 1 January 2026.
