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liraglutide

the first GLP-1 weight loss drug. saxenda and victoza. now outclassed by semaglutide and tirzepatide.

tier S · weight loss · FDA '14 Saxenda · obesity

verdict

the first GLP-1 for weight loss. saxenda for obesity, victoza for T2D. outclassed by semaglutide and tirzepatide now, but still on the shelf and still labeled.

if you're asking whether to start liraglutide today — STEP 8 ended the default. semaglutide 2.4 mg hit 15.8% weight loss vs liraglutide 3 mg's 6.4% in the head-to-head. daily injection vs weekly is the practical dealbreaker. the remaining case for lira is insurance pathway, pediatric eligibility, or tolerance for lira but not the weekly drugs.

if you're asking about pediatric or adolescent use — Saxenda still has the deepest pediatric obesity data in the class, including the 2025 extension into children 6-12. semaglutide caught up for adolescents (≥12 years) but liraglutide remains the molecule with the longer pediatric outcome record.

if you came in for the cost angle — Meitheal launched a generic April 2025; Teva followed in August 2025. pricing has dropped versus branded but absolute cost still sits above most weekly branded competitors under common insurance pathways. the cost gap is closing slowly.

based on published evidence and disclosed clinical practice. not medical advice. dose and protocol conversations belong with a clinician.

why S-tier

the drug that started the modern GLP-1 era. first GLP-1 agonist approved for obesity (2014). mechanism works, cardiovascular benefit documented, pediatric approval for adolescents. weight loss is meaningful (6-8%) but dwarfed by sema/tirz/reta. daily injection is the clinical dealbreaker for most patients vs weekly alternatives. S because the bar for S is drug-tier evidence and lira has it. But it's the bottom of S. Practically obsolete for weight loss in 2026 except for pediatric/adolescent use.

the core tension

It walked so semaglutide could run. The first GLP-1 agonist approved for obesity, the drug that proved the mechanism in humans, the foundation the entire GLP-1 boom sits on. Now the established budget option as newer molecules carry the category forward.

what it is

A 31-amino-acid GLP-1 receptor agonist. One amino acid swap (Lys to Arg at position 34) and a fatty acid chain at position 26 stretch the half-life from native GLP-1's 2 minutes to about 13 hours. Sold by Novo Nordisk as Victoza (T2D, 2010) and Saxenda (obesity, 2014). Teva shipped an authorized Victoza generic June 2024. FDA approved the first ANDA generic referencing Victoza in December 2024. Meitheal launched generic Saxenda April 2025, Teva followed in August 2025. More manufacturers since February 2026 are forcing price compression. The first generic GLP-1s, and the floor is still moving.

what it does

Same GLP-1 pharmacology as semaglutide: cuts appetite, delays gastric emptying, glucose-dependent insulin secretion, glucagon suppression. SCALE Obesity & Prediabetes: 8.0% mean weight loss at 3mg daily over 56 weeks. LEADER: 13% relative MACE reduction in T2D patients with high cardiovascular risk. The effect is real. Sema and tirzepatide just doubled it.

origin

Built at Novo Nordisk under Lotte Bjerre Knudsen, the second-generation GLP-1 program after exenatide proved the class could work. Victoza FDA approved 2010 for type 2 diabetes. Saxenda 2014 for obesity, the first GLP-1 ever approved specifically for weight loss. Pediatric approval 2020 for adolescents 12-17. Without liraglutide's commercial success, semaglutide doesn't get developed.

why researchers are interested

Historical respect for the molecule that started everything. Practical use today is narrower: insurance forces it when sema and tirzepatide aren't covered, pediatric obesity where lira has data beyond the adolescent frame, patients who tolerate lira but not the weekly drugs. Newer pediatric data extending to children 6-12 has strengthened the niche.

does it work

Yes, but. STEP 8 was the moment clinicians stopped defaulting to liraglutide for adult obesity: semaglutide 2.4mg hit 15.8% weight loss vs lira 3.0mg's 6.4% at 68 weeks. Daily injection is the clinical dealbreaker against weekly competitors. Cardiovascular benefit documented, pediatric efficacy documented, generic price has barely moved (~$1,165/month). In adult obesity, liraglutide is the legacy GLP-1. The remaining relevance is pediatric use, insurance-driven access, and a long safety record.

claims vs the data

  • causes meaningful weight loss — supported — SCALE trial: 8% avg weight loss at 3mg daily over 56 weeks. less than sema/tirz but real.
  • reduces cardiovascular events — supported — LEADER trial 2016: 13% MACE reduction in T2D patients with high CV risk, n=9340.
  • works in adolescents — supported — first GLP-1 approved for pediatric obesity (12-17yo) in 2020. n=251 trial showed similar efficacy.
  • better than newer GLP-1s — contradicted — sema 2.4mg head-to-head: 15.8% vs lira's 6.4% at 68 weeks. tirz does even better.
  • keeps weight off after stopping — contradicted — SCALE maintenance: regained most loss within 12 months off-drug. same as sema/tirz.
  • daily injection is fine actually — weak — adherence data shows substantially worse compliance vs weekly options. most patients switch.
  • generic versions are identical — supported — authorized generics via Teva are manufactured by Novo Nordisk. ANDA generics FDA-verified bioequivalent.
  • liraglutide is obsolete everywhere — overreach — For adult weight loss, weekly semaglutide and tirzepatide beat it clearly. The page changes when pediatric obesity, adolescent data, cardiovascular outcomes, and generic access enter the frame. Liraglutide is a legacy adult drug, not a dead molecule.

key facts

  • molecular formula: C₂₁₂H₂₆₃N₄₃O₆₂
  • molecular weight: 3751.2 g/mol
  • amino acids: 31
  • half-life: ~13 hours
  • type: GLP-1 receptor agonist
  • CAS: 204656-20-2
  • ~6-8% avg weight loss
  • 2010 victoza FDA approval
  • 2025 first generic for obesity
  • daily injection (vs weekly sema)

frequently asked questions

What is liraglutide?

Liraglutide is a once-daily GLP-1 receptor agonist, 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).

What does liraglutide do?

Liraglutide reduces appetite and improves insulin response via GLP-1 receptor activation. The Saxenda trials showed mean weight loss of approximately 8% of body weight over 56 weeks. Weight loss is more modest than semaglutide due to shorter half-life and daily rather than weekly dosing.

How is liraglutide typically administered?

Liraglutide is administered as a once-daily subcutaneous injection. FDA-approved Saxenda dosing starts at 0.6mg per day and titrates over 4-5 weeks to the maintenance dose of 3.0mg per day. Victoza dosing for diabetes is lower, typically maintaining at 1.2-1.8mg per day.

What are the side effects of liraglutide?

The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, and constipation. Side effect intensity is typically milder than semaglutide, but daily dosing means daily exposure. The class-wide boxed warning for thyroid C-cell tumors based on rodent studies applies.

Is liraglutide FDA approved?

Yes. Liraglutide is FDA-approved as Victoza (2010, type 2 diabetes) and Saxenda (2014, chronic weight management). Generic liraglutide was approved in 2024.

How much does liraglutide cost?

Branded Saxenda retails for approximately $1300 per month without insurance; Victoza is similarly priced. Generic liraglutide launched in 2024 at roughly half the price of branded versions. Liraglutide has largely been displaced in the market by more effective weekly-dosed alternatives like semaglutide and tirzepatide.

related peptides

  • semaglutide — weekly successor from the same company
  • tirzepatide — dual-agonist alternative
  • retatrutide — triple-agonist in development

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.