Liraglutide
Liraglutide (Victoza / Saxenda) — evidence, the pioneer story & status

Class: peptide
Synonyms: liraglutide
GLP-1 receptor agonist
brands Victoza (type-2 diabetes), Saxenda (obesity)
Saxenda (obesity brand)
Victoza (type-2 diabetes brand)
Function tags: metabolic
type-2 diabetes
obesity / weight
cardiovascular (all approved)
Overall evidence grade: A
WADA prohibited: no
WADA note: Sport: GLP-1 agonists are not currently on the WADA Prohibited List.
Last updated: 2026-07-13

In brief: Liraglutide is the pioneer GLP-1 — the first in wide use and the first approved for obesity (Saxenda, 2014), the drug that opened the field for semaglutide and tirzepatide. It is FDA-approved for type-2 diabetes, obesity and cardiovascular risk (grade A), and in 2024–2025 became the first GLP-1 to go generic, meaningfully widening access. Its trade-offs are honest: it's a daily injection and less potent than the newer drugs (~8% weight loss vs semaglutide ~15% and tirzepatide ~22%) — eclipsed on efficacy, but proven, long-tracked, and now affordable.

## Identity an **acylated GLP-1 analog** — a ~31-amino-acid peptide (< 40 aa → peptide) based on human GLP-1 with a palmitoyl fatty-acid chain that binds albumin, giving a **~13-hour half-life** and therefore a **once-daily** injection (the defining contrast with semaglutide's once-weekly). It is marketed under the trade names **Victoza** (type-2 diabetes) and **Saxenda** (obesity/weight management). ## Mechanism (as proposed) a GLP-1 receptor agonist — enhances **glucose-dependent insulin** secretion, suppresses **glucagon**, slows **gastric emptying**, and reduces **appetite**. The palmitoyl-albumin design gives a ~13-hour half-life → **daily** dosing (vs semaglutide's weekly), which is also why it clears faster (an advantage before surgery or pregnancy).

Evidence grades by outcome:
outcome: Type-2 diabetes glycemic control
grade: A
base: Phase 3 (LEAD programme); FDA-approved
effect: Robust HbA1c reduction
caveat: Slightly less than semaglutide (SUSTAIN-10)
outcome: Chronic weight management (obesity)
grade: A
base: SCALE Phase 3 (~8.4% at 56 wk); FDA-approved (first GLP-1 for obesity)
effect: Meaningful weight loss
caveat: Less than semaglutide (~15%) / tirzepatide (~22%); daily injection; head-to-head STEP 8 = 6.4% vs 15.8%
outcome: Cardiovascular risk reduction (T2D + CVD)
grade: A
base: LEADER (n=9,340); FDA-approved
effect: 13% reduction in major CV events
caveat: In T2D + established CVD only — not generalisable to non-diabetic obesity (unlike semaglutide's SELECT)
outcome: Pediatric obesity (adolescents 12+)
grade: A
base: Kelly 2020 (NEJM); FDA-approved
effect: Reduced BMI standard-deviation score
caveat: Longest pediatric track record in the class
outcome: Safety
base: Large trials + 15+ years post-marketing
effect: Well-characterised (longest record in class)
caveat: GI effects; gallbladder events (1–2%); rare pancreatitis; boxed thyroid C-cell warning (rodent); more injection-site reactions (7× the injections of a weekly drug)

Legal status:
region: US
status: Approved / prescription
note: FDA- and EMA-approved (Victoza, Saxenda, and generics). Unlike semaglutide/tirzepatide, it is not caught in the shortage/compounding situation — approved generics exist.

Cosmetic claims:

Note: Reference entry — NOT a sellable lane. An FDA-approved prescription drug (now also generic), not a cosmetic or research peptide. It earns its place in the register for two reasons that are genuinely historic: it was the first GLP-1 approved for obesity, and it was the first GLP-1 to go generic. No dosing published here.

Sources:
Marso SP, et al. Liraglutide and cardiovascular outcomes in type-2 diabetes (LEADER). N Engl J Med. 2016.
Pi-Sunyer X, et al. (SCALE Obesity and Prediabetes — liraglutide for weight management.) N Engl J Med. 2015.
Rubino DM, et al. (STEP 8 — semaglutide vs liraglutide head-to-head for weight loss.) JAMA. 2022.
Kelly AS, et al. (Liraglutide for adolescents with obesity.) N Engl J Med. 2020.
FDA prescribing information (Victoza/Saxenda) and generic approvals (Teva/Hikma, 2024–2025).