What Is Liraglutide? Dosage, Half-Life & How to Track It

What liraglutide is and how it works

Liraglutide was the first once-daily GLP-1 receptor agonist to reach the market, years before semaglutide. It works the same way every drug in this class does — mimicking GLP-1, slowing gastric emptying, and quieting appetite signaling — but it uses a shorter fatty-acid modification to bind albumin than semaglutide does, which is the molecular reason its half-life tops out around 13 hours instead of a full week.

That half-life difference is the whole story behind why liraglutide is a once-daily injection while semaglutide and tirzepatide are once weekly. The same molecule is sold under two brand names for two indications: Victoza for type 2 diabetes (up to 1.8 mg/day) and Saxenda for chronic weight management (up to 3.0 mg/day) — same drug, different approved dose ceiling and indication.

Because it predates semaglutide, liraglutide has the longest track record among once-daily GLP-1 drugs, but head-to-head data generally shows semaglutide and tirzepatide producing more weight loss at their respective maximum doses — part of why liraglutide has become the older, less commonly prescribed option for weight management specifically.

Typical dosing & titration

Liraglutide ships in a pre-filled pen, and like every drug in this class, the escalation is gradual and weekly to manage nausea:

• Week 1: 0.6 mg
• Week 2: 1.2 mg
• Week 3: 1.8 mg
• Week 4: 2.4 mg
• Week 5+: 3.0 mg (Saxenda maintenance) or 1.8 mg (Victoza max)

The approved pen ships pre-mixed at a fixed concentration; reconstitution math only applies to compounded or research-vial formats. Unlike a weekly compound, a missed liraglutide dose behaves more like a missed daily medication than a missed weekly shot — there is no multi-week accumulation to fall back on.

Half-life & what it means for frequency

Liraglutide’s roughly 13-hour half-life is long enough to support once-daily dosing — each dose is still meaningfully present the next day — but far short of the roughly week-long half-lives that let semaglutide, tirzepatide, and the newer GLP-class drugs go once weekly. That gap comes down entirely to how tightly the drug’s fatty-acid tail binds albumin.

The practical upshot: liraglutide reaches steady state faster (within a few days) than a weekly compound does (which can take a month), but it also clears faster if stopped — appetite suppression fades within a couple of days rather than the multi-week tail seen after stopping semaglutide.

What to track & common side effects

Side effects follow the class-wide GI pattern — nausea, constipation, and diarrhea, concentrated around each weekly dose increase — generally comparable in kind to semaglutide, though many users report it as somewhat more nausea-prone at equivalent points in titration, likely related to the faster onset from daily dosing.

The tracking priorities are the same as any GLP-1: log the daily dose so a missed injection is visible immediately, since there is no week of cushion; trend weight and waist rather than any single reading; and keep protein intake in view since appetite suppression this effective makes under-eating protein easy.

Frequently asked questions