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Liraglutide

Also known as Victoza, Saxenda, NN2211

Daily GLP-1 receptor agonist for type 2 diabetes and weight management.

clinically proven Metabolic & weight approved drug

At a glance

Category
Metabolic & weight
Status
approved drug
Made from
recombinant The peptide precursor is expressed in Saccharomyces cerevisiae, then chemically acylated with a palmitic acid side chain via a glutamic acid spacer.
Route
subcutaneous, 1x per day
Half-life
approximately 13 hours in humans after subcutaneous administration 4
Onset
weight loss from a few weeks onwards; maximum effect after 6-12 months
Molecular weight
3751.2 g/mol (molecular formula C172H265N43O51) 4
Sequence
31-amino acid GLP-1(7-37) analogue; Lys34 replaced by Arg and Lys26 acylated with palmitic acid (C16) via a γ-glutamate linker

Registered by the EMA and FDA: Victoza (type 2 diabetes, up to 1.8 mg/day) and Saxenda (weight management, up to 3.0 mg/day). Since the patent expired, generic versions have become available. Prescription only.

Doping status: Not listed by WADA

Checked against the WADA 2026 Prohibited List. For a specific product and country, Global DRO is the lookup athletes are expected to use — the List names substances, not brand names.

Mechanism of action

Liraglutide is an acylated GLP-1 analogue with 97% homology to human GLP-1. It binds to the GLP-1 receptor and enhances glucose-dependent insulin secretion, inhibits glucagon release and slows gastric emptying.

The weight effect arises mainly via central appetite suppression: liraglutide reaches GLP-1 receptor populations in the hypothalamus, area postrema and nucleus tractus solitarii, increasing satiety and reducing hunger. Studies with controlled meals showed lower ad libitum energy intake.

The palmitic acid chain provides reversible binding to albumin and self-association into heptamers in the subcutaneous depot; both slow absorption and degradation. The resulting half-life of approximately 13 hours makes daily dosing possible — considerably shorter than the approximately 7 days of semaglutide.

What the research shows

Extensively studied in large randomised phase 3 programmes (LEAD in diabetes, SCALE in obesity) and in a cardiovascular outcomes study (LEADER). The effect size on weight is clearly smaller than that of semaglutide and tirzepatide, which has been confirmed in direct comparative studies.

Research in humans

SCALE Obesity and Prediabetes (n=3731, 56 weeks) showed a mean weight loss of 8.0% (8.4 kg) with liraglutide 3.0 mg versus 2.6% (2.8 kg) with placebo 1. LEADER (n=9340) showed, in type 2 diabetes with high cardiovascular risk, a significant reduction in cardiovascular mortality and the composite MACE endpoint. In STEP 8, semaglutide 2.4 mg per week produced considerably more weight loss than liraglutide 3.0 mg per day.

Animal and lab research

In rat and mouse studies, liraglutide caused dose- and duration-dependent C-cell hyperplasia and tumours of the thyroid. Post-marketing registries in humans have so far not demonstrated a clearly raised risk of medullary thyroid carcinoma, but the duration of follow-up is limited.

Caveats. The registration studies were funded by Novo Nordisk. Daily injections lead to lower adherence than weekly alternatives. Weight regain after stopping has been described. The effect on weight is clinically relevant but modest compared with the newer incretin drugs.

What it is used for

  • Type 2 diabetes mellitus, as an adjunct to diet and exercise (Victoza)
  • Chronic weight management in obesity or overweight with comorbidity (Saxenda), also in adolescents from 12 years of age weighing more than 60 kg 5
  • Reduction of cardiovascular risk in type 2 diabetes with established cardiovascular disease
  • Historically used as a first-generation GLP-1 option; in practice largely superseded by weekly agents

Dosing

Dose
Victoza: 0.6 mg to 1.8 mg per day. Saxenda: 0.6 mg to 3.0 mg per day.
Frequency
1x daily, at any time but preferably a fixed one, independent of meals
Route
Subcutaneous in the abdomen, thigh or upper arm
Duration
Chronic; both labels set a stopping rule at the 3.0 mg Saxenda dose, but the EU and US thresholds differ — see the dosing notes
  • Saxenda titration schedule: week 1 0.6 mg/day, week 2 1.2 mg/day, week 3 1.8 mg/day, week 4 2.4 mg/day, from week 5 onwards 3.0 mg/day. Increases in steps of 0.6 mg per week 5.
  • Victoza titration schedule: start at 0.6 mg/day for at least one week — a starting dose intended to reduce gastrointestinal effects and not effective for glycaemic control — then 1.2 mg/day. If needed, increase to 1.8 mg/day (maximum) after at least one week 4.
  • If a titration step is not tolerated, the increase can be postponed by approximately a week.
  • If a dose is missed, the next dose is taken at the usual time; no double dose is given. After an interruption of more than 3 days, treatment is restarted at 0.6 mg and re-titrated 4.
  • The two Saxenda labels disagree on when to stop for lack of effect, and the difference is not trivial. The EU SmPC says to discontinue after 12 weeks on 3.0 mg/day if the patient has not lost at least 5% of initial body weight 2. The US label says to evaluate at 16 weeks and discontinue if the patient has not lost at least 4% of baseline body weight 5. A patient judged a non-responder under one rule can still be on treatment under the other.
  • The doses are the official registered schedules. This is reference information, not treatment advice.
  • A grey-market and 'microdosing' pattern also circulates for liraglutide and is set out as a circulating protocol below. The label directs a fixed titration ladder in a metered pen 45; the circulating use borrows the numbers but self-titrates, microdoses below the studied range or reconstitutes powder on an insulin syringe. Those figures come from user reports and compounding or research-chemical labelling, not from any trial, and are recorded because readers meet them, not because they are validated.

These figures describe what the literature and published protocols report. They are not advice and not a dosing instruction.

Protocols

Saxenda titration (weight management)

approved product information

Source: FDA prescribing information for Saxenda (DailyMed)

Week 10.6 mg subcutaneously once daily
Week 21.2 mg once daily
Week 31.8 mg once daily
Week 42.4 mg once daily
Week 5 onward3 mg once daily (maintenance)

Steps are weekly, not four-weekly, because this is a daily injection rather than a weekly one. In paediatric patients a dose that is not tolerated may be lowered to the previous level and escalation may take up to 8 weeks; if 3 mg cannot be tolerated the paediatric maintenance dose may be 2.4 mg. Adults who cannot tolerate 3 mg should discontinue.

Victoza titration (type 2 diabetes)

approved product information

Source: FDA prescribing information for Victoza (DailyMed)

Week 10.6 mg subcutaneously once daily (initiation; not effective for glycaemic control)
Week 2 onward1.2 mg once daily
After at least one week at 1.2 mg1.8 mg once daily, if additional glycaemic control is required

Same molecule as Saxenda, different ceiling: Victoza stops at 1.8 mg where Saxenda continues to 3 mg. The two are not interchangeable pens.

Grey-market and 'microdosing' self-use (circulating)

user protocol — not validated

Source: GLP-1 and weight-loss forums, compounding-pharmacy and research-chemical labelling

This is not a validated schedule. It is a pattern that circulates among users and sellers, reproduced because it is what people actually follow — not because it has been tested. No trial established these doses, this interval or this duration, and nobody is checking what is in the vial. Treat every number below as an assertion, not a finding.

Reported self-titrationstarting around 0.6 mg daily and increasing by feel toward 1.8-3.0 mg, with the ladder compressed or stretched relative to the label depending on tolerance
'Microdosing'deliberately staying at low sub-therapeutic amounts (roughly 0.25-0.6 mg) long-term, to limit nausea or as claimed 'maintenance' — a pattern with no studied basis
How it is preparedgrey-market or compounded liraglutide, sometimes reconstituted from powder and drawn up on an insulin syringe rather than a metered pen

The two approved schedules above are fixed titration ladders in a metered multidose pen 45; the circulating use borrows those numbers but detaches them from the pen, the prescription and the monitoring. Liraglutide is daily and has largely been superseded by weekly agents, so it is less prominent on the grey market than semaglutide or tirzepatide, but it is sold the same way. Two divergences recur. First, self-titration: users compress or extend the ladder by feel, which mainly changes how badly they tolerate it. Second, 'microdosing' — staying deliberately below the studied doses — is promoted as gentler or as maintenance, but no trial has evaluated sub-therapeutic liraglutide for weight maintenance, so the claimed benefit is asserted rather than shown. Where powder is reconstituted and measured on an insulin syringe, the milligram-to-unit conversion is the documented failure point for this drug class: regulators have recorded patients self-administering many times the intended dose of a compounded GLP-1 after confusing millilitres, milligrams and syringe 'units'. Grey-market material also carries no assurance of identity, strength or sterility. These figures are recorded because they circulate, not because they are validated.

Schedules are reproduced as their source states them. Units, IU and milligrams explains why the figures are not interchangeable between products.

Reconstitution

Storage
Unused pens: 2-8 °C, do not freeze, protected from light. After first use, keeps for up to 1 month at a maximum of 30 °C or in the refrigerator.

Worked example

Not applicable. Liraglutide is supplied as a ready-to-use solution in a pre-filled multidose pen with a continuously adjustable dose dial; nothing is dissolved or mixed.

Liraglutide is chemically less stable than the weekly analogues and is sensitive to freezing; a pen that has been frozen must be discarded.

Safety

Side effects

  • Nausea, vomiting, diarrhoea, constipation — very common, especially in the first weeks
  • Headache, dizziness, fatigue
  • Injection site reactions
  • Gallstones and gallbladder inflammation, especially with rapid weight loss; cholelithiasis occurred in 2.2% of Saxenda-treated versus 0.8% of placebo-treated patients 5
  • Acute pancreatitis (rare); the label directs discontinuation if pancreatitis is suspected 4
  • Increased heart rate (mean increase of 2-3 beats per minute) 4
  • Hypoglycaemia in combination with sulfonylureas or insulin, which may require reducing the dose of those agents 4
  • Worsening of diabetic retinopathy with rapid glycaemic improvement
  • Delayed gastric emptying; rare reports of pulmonary aspiration of gastric contents during general anaesthesia, which the label says should be disclosed to the anaesthetist 4
  • Reports of suicidal thoughts and behaviour were reviewed by the EMA in 2024, which found no causal link. A 'Suicidal Behavior and Ideation' warning previously carried in the US Saxenda labelling was no longer present in the label version checked in July 2026 5

Do not use if

  • Personal or family history of medullary thyroid carcinoma (MTC) — a labelled contraindication 4
  • Multiple endocrine neoplasia type 2 (MEN2) — a labelled contraindication 4
  • Serious hypersensitivity to liraglutide or any of the excipients — a labelled contraindication 4
  • History of pancreatitis — relative contraindication
  • Severe heart failure (NYHA class IV) — insufficient data
  • Pregnancy and breastfeeding
  • FDA boxed warning: liraglutide causes thyroid C-cell tumours at clinically relevant exposures in both sexes of rats and mice, and it is unknown whether it causes medullary thyroid carcinoma in humans 4

Interactions

Liraglutide delays gastric emptying and may thereby affect the absorption of concomitantly administered oral medicines 4; clinically relevant interactions have proved limited in studies. In combination with sulfonylureas or insulin, a dose reduction of those agents is often needed because of the risk of hypoglycaemia. Concurrent use with other GLP-1 receptor agonists or with DPP-4 inhibitors is not recommended because of the overlapping mechanism of action without demonstrated added value. Because of delayed gastric emptying, anaesthesiology guidelines advise adjusting fasting policy around procedures.

Sources