Liraglutide
FDA-approved first-generation GLP-1 receptor agonist · once-daily (SC)
Liraglutide is an FDA-approved GLP-1 receptor agonist — a copy of the gut hormone GLP-1, and the first-generation predecessor to today's once-weekly drugs. It is sold as Victoza for type 2 diabetes and as Saxenda for weight management, and it works through exactly the same four mechanisms as semaglutide. The key difference is pharmacokinetic, not mechanistic: liraglutide's shorter (~13-hour) half-life means it must be injected once daily, seven times as often as weekly semaglutide or tirzepatide. It is also meaningfully less powerful on weight — the SCALE obesity trial produced about 7.9% mean weight loss, versus roughly 15% for semaglutide and over 20% for tirzepatide in their pivotal trials. Why it still matters: it was historically pivotal (the LEADER trial first established that GLP-1 drugs reduce cardiovascular events), it is still clinically used, and it became cheaper after US generics launched in December 2024. The same class caveats apply — gastrointestinal side effects, some lean-mass loss, weight regain after stopping, and a boxed thyroid warning.
The short version
Liraglutide is a man-made copy of GLP-1, the hormone your gut releases after a meal that tells the pancreas to make insulin, slows the stomach, and signals fullness. It is the older, first-generation version of this drug class — the one that came before the now-famous weekly injections.
It is an approved medicine sold under two brand names: Victoza, a once-daily injection for type 2 diabetes, and Saxenda, a higher-dose once-daily injection for weight loss. In December 2024 the first US generics arrived, making it cheaper than the newer branded options.
The honest framing is that liraglutide has largely been superseded. It works the same way as semaglutide (Ozempic/Wegovy) but has to be injected every day instead of weekly, and it produces less weight loss. It still matters historically — it was the first GLP-1 drug shown to cut heart attacks and strokes — and it remains a useful, lower-cost option, but on raw effectiveness the weekly drugs have moved ahead of it.
Molecular identity
Specs
- Molecular weight
- ~3751.2 Da
- Molecular formula
- C172H265N43O51
- Monoisotopic mass
- 3748.95 Da
- Molecular target
- GLP-1 receptor (agonist)
- Amino acids
- 31-residue backbone (97% homology to GLP-1(7-37))FDA label; PubChem CID 16134956
- Structure / class
- Acylated GLP-1 receptor agonist; Arg34, Lys26 C16-palmitoyl via γ-Glu spacer; >98% albumin-boundFDA label; review literature
- CAS / UNII
- 204656-20-2 · 839I73S42APubChem CID 16134956; FDA UNII
- Brand / approval
- FDA-approved — Victoza (T2D, 2010), Saxenda (obesity, 2014); US generics 2024FDA label
- Regulatory status
- FDA-approved drug; not prohibited by WADA (liraglutide not individually named on the 2026 Monitoring Program)FDA / WADA 2026
Plain English
Mechanism
Liraglutide is a GLP-1 receptor agonist — "agonist" means a molecule that switches a receptor on, and GLP-1 (glucagon-like peptide-1) is an incretin, a gut hormone released after eating. It acts on the same receptor as semaglutide and tirzepatide and produces the same four core effects.
First, glucose-dependent insulin secretion: it tells the pancreas to release more insulin (the hormone that lowers blood sugar), but mainly when blood sugar is high, so on its own it rarely causes hypoglycemia (dangerously low blood sugar). Second, glucagon suppression: it lowers glucagon (the hormone that tells the liver to release sugar), reducing the liver's glucose output. Third, slowed gastric emptying: food leaves the stomach more slowly, blunting the post-meal blood-sugar spike and prolonging fullness. Fourth, central satiety: it acts on appetite centers in the brain (the hypothalamus) to reduce hunger and calorie intake — the basis for the Saxenda weight-loss indication.
The key honesty point is that liraglutide's difference from the newer drugs is pharmacokinetic, not mechanistic. It is the same receptor and the same four mechanisms as semaglutide; what differs is how long it lasts. Its shorter ~13-hour half-life forces daily injection, whereas semaglutide's albumin-optimized longer half-life allows once-weekly dosing.
Sources:DailyMed (Victoza)PMID 27295427
Why people reach for it
Potential benefits
Liraglutide is the original GLP-1 — less powerful than today's weekly agents, but approved, well-studied, and now cheaper. Here's what people still reach for it for, honestly framed.
- Genuine, approved weight loss — As Saxenda it produced about 7.9% mean weight loss in the SCALE trial — real and clinically meaningful, even if it's roughly half what Semaglutide or Tirzepatide deliver.
- Appetite turned down — It acts on the brain's appetite centers and slows the stomach, reducing hunger and making a calorie deficit easier to hold — the basis of its weight indication.
- Steadier blood sugar — As approved Victoza for type 2 diabetes, it lowers blood sugar through glucose-dependent insulin and glucagon suppression, and rarely causes lows on its own.
- A proven heart-risk reduction — It was the first GLP-1 shown to cut cardiovascular events — the landmark LEADER trial — which is a large part of why it still matters clinically.
- A lower-cost option — Since US generics launched in December 2024, it became the cheaper GLP-1, which matters in cost-sensitive or access-limited situations.
- Daily dosing can be a feature — A once-daily rhythm lets you read your appetite response day to day and adjust the routine around it — and it pairs naturally with a daily training schedule.
Sources:PMID 26132939PMID 27295427PMID 19515413DailyMed (Victoza)
What people reach for Liraglutide for, based on what the trials report and how it's used — real approved outcomes, but paired with their honest costs (daily injections, less weight loss than the weekly agents, GI side effects, some lean-mass loss, regain after stopping), not a cure or a guarantee.
Implied timing
Best time to dose
Implied best time
Same time daily
Most people take Liraglutide once a day at the same time — the consistency matters more than the exact hour, and the hour you pick can be tuned to how you handle it.
- Unlike the weekly GLP-1s, liraglutide's half-life is only about 13 hours — short enough that it must be injected once daily, and a fixed daily time keeps plasma levels even from one day to the next.
- It can be taken with or without food; the label places no meal restriction, so the choice of hour is about your routine, not absorption.
- Morning vs evening is a personal tuning call: a morning dose lets you read appetite suppression through the day, while an evening dose lets you sleep through any early nausea — both are valid, so pick the one that fits how you tolerate it.
- Effects build over weeks of titration, so no single dose's timing changes the result — daily consistency does.
No study establishes an ideal time of day for Liraglutide — this is reasoned from its ~13-hour half-life and how it's used. The usual peptide-dosing default is the midday-to-evening window; for this daily agent the real lever is the same time every day, with morning or evening tuned to your own tolerance.
Sources:DailyMed (Victoza)
How to run it
Dosing & protocol
Liraglutide is FDA-approved with a genuine published titration schedule — the numbers below are straight from the label. The defining practical feature: it is injected once daily because its ~13-hour half-life is too short for weekly dosing. Slow escalation is the protocol — titration is how you minimize nausea and stay on the drug long enough for it to work.
FDA-approved prescribing information. These titration steps are the genuine label schedule, not community guesswork. They describe the approved regimens for context; this is not a self-medication guide.
Titration schedule
Both Victoza and Saxenda start far below the maintenance dose and step up weekly — gut side effects are dose-related, so a gradual climb keeps nausea manageable.
- Victoza (T2D):
- 0.6 mg once daily × ≥1 week (tolerability dose only — not yet effective for glucose control) → 1.2 mg once daily → increase to 1.8 mg once daily if further blood-sugar control is needed. Maximum: 1.8 mg/day.
- Saxenda (weight management):
- 0.6 mg once daily × 1 week → 1.2 mg × 1 week → 1.8 mg × 1 week → 2.4 mg × 1 week → 3.0 mg/day (maintenance). If a step is not tolerated, hold at the previous dose for an additional week before escalating. If 3.0 mg is still not tolerated, the label advises discontinuing.
- The key difference from weekly agents:
- Daily injection is not a design choice — it is a pharmacokinetic constraint. Liraglutide's C16 palmitoyl chain extends the half-life to ~13 h, enough for once-daily but not once-weekly. The newer drugs' longer chains and optimized albumin binding reach a full week. Seven injections per week vs one is the single biggest practical trade-off against semaglutide or tirzepatide.
- Efficacy benchmark:
- Saxenda at 3.0 mg/day produced ~7.9% mean weight loss (−8.4 kg) in the SCALE trial — real and clinically significant, but less than semaglutide (~15%) or tirzepatide (~20%+). Set expectations accordingly.
Subcutaneous administration
Liraglutide is injected subcutaneously (under the skin). Site choice and timing are the daily-execution decisions.
- Injection site:
- Abdomen (staying a few inches clear of the navel), upper thigh, or upper arm. Rotate sites between doses — same mechanism, same lipohypertrophy risk as any daily SC injection. Using the same spot repeatedly creates fatty nodules that slow absorption unpredictably.
- Time of day:
- Any time of day, independent of meals — but pick one fixed daily time and hold it, since the ~13 h half-life means a consistent hour keeps plasma levels even. Morning or evening can be tuned to how you tolerate it (see Best time to dose above). The label places no meal restriction on liraglutide.
- Food window:
- No meal restriction. Unlike some metabolic agents, subcutaneous liraglutide absorption is not affected by food timing. Consistent site + consistent time = consistent plasma levels.
- Pre-filled pen (branded form):
- Victoza and Saxenda come as pre-filled multi-dose pens (0.6 mg, 1.2 mg, 1.8 mg dial steps for Victoza; Saxenda pen dials 0.6 mg increments). For a reconstituted research vial, use the calculator on this page to convert each dose to syringe units.
Cycle / duration
Liraglutide is approved as an ongoing, chronic therapy — there is no planned washout because the benefit depends on continued use.
- Duration:
- Open-ended continuous therapy, not a timed cycle. This distinguishes it from research peptides that are pulsed on fixed schedules. Stopping = losing the effect: as with the whole GLP-1 class, weight (and glycemic benefit) gradually returns after discontinuation, over weeks to months.
- Stopping decision:
- The Saxenda label recommends reassessment at 16 weeks: if a patient has not lost at least 4% of baseline body weight, continuing is unlikely to produce meaningful benefit — the label says to consider stopping.
- Lean-mass caveat:
- A fraction of weight lost is muscle, not fat. Protein 1.6–2.0 g/kg/day + resistance training is the counter (see Cofactors) — this has to be proactive because appetite suppression makes it easy to under-eat protein by default.
Reconstitution at a glance
Branded pens come ready to use. For a research vial, the calculator on this page handles the math; the standard reference for a 5 mg vial:
- Standard mix:
- 5 mg vial + 2 mL bacteriostatic water = 2.5 mg/mL (2,500 mcg/mL). On a 100-unit (1 mL) insulin syringe: 0.6 mg = 24 IU · 1.2 mg = 48 IU · 1.8 mg = 72 IU · 3.0 mg = 120 IU (two draws from a 100-unit syringe).
Substrate the signal needs
Nutritional cofactor precision
The GLP-1 mechanism creates predictable costs: GI side effects during titration, lean-mass loss alongside fat loss, and micronutrient gaps from eating less. Cofactors here are MITIGATE-dominant — the most important work is managing side effects and preserving muscle so the weight lost is the right kind of weight.
Reasoned from GLP-1 physiology and weight-loss nutrition — not a liraglutide supplement trial. Supplement doses are evidence-informed community ranges; liraglutide-specific cofactor studies do not exist.
MITIGATE — GI side effects (nausea + constipation)
Nausea is worst during the titration weeks; constipation is a persistent downstream effect of slowed gastric emptying. These are the two that knock people off the drug.
- Ginger (nausea):
- 1–2 g ginger (as capsules or crystallized) 20–30 minutes before injection or a meal during titration weeks. Ginger's 5-HT3 antagonism targets the same nausea signaling pathway activated by GLP-1 agonists. This is the frontline move for titration nausea.
- Vitamin B6 (nausea):
- 25–50 mg pyridoxine daily — the standard adjunct to ginger for GI-related nausea. Take with the ginger or at the same meal.
- Magnesium (constipation):
- 300–400 mg magnesium glycinate or citrate at night. Slowed gastric emptying extends all the way through the gut; magnesium draws water into the colon and supports motility. Glycinate form avoids the additional loose-stool risk of magnesium oxide.
- Dietary fiber + hydration (constipation):
- 25–35 g/day dietary fiber (psyllium, vegetables, legumes) plus ≥2 L water. Fiber without adequate hydration worsens constipation. On the daily rhythm of liraglutide, this is a daily discipline, not a one-time fix.
MITIGATE — electrolytes (eating less = losing electrolytes)
Reduced food volume cuts sodium, potassium, and magnesium intake. On daily dosing, those deficits accumulate steadily.
- Sodium:
- Do not over-restrict salt while on a GLP-1 agonist. Eating less means getting less dietary sodium; hyponatremia symptoms (brain fog, fatigue, headache) are common and often misattributed to the drug. Add salt to food or use electrolyte drinks with meals.
- Potassium:
- Maintain potassium-rich foods (avocado, leafy greens, banana, salmon) or add a potassium supplement 100–200 mg/day. Low potassium + low food volume is a common hidden depletion.
- Magnesium (double duty):
- The 300–400 mg magnesium from the constipation card above covers the electrolyte gap as well — one supplement, two jobs.
SUPPLY / PRESERVE — lean mass (the most important cofactor group)
GLP-1 agonists suppress appetite indiscriminately — protein intake drops alongside calorie intake. Muscle preservation is not automatic; it requires deliberate overcorrection.
- Protein target:
- 1.6–2.0 g protein per kilogram of body weight per day (roughly 0.7–0.9 g/lb). This is more than default dietary habits and has to be structured: protein-first at each meal before appetite suppression ends the meal. This is the single highest-leverage move on any GLP-1 protocol.
- Resistance training:
- 2–4 sessions per week of resistance training is the evidence-based complement to high protein. The combination preserves significantly more lean mass during caloric deficit than either alone. Liraglutide's daily injection cadence makes daily consistency easier to pair with a structured training schedule.
- Creatine monohydrate:
- 3–5 g/day creatine monohydrate, any time. Creatine supports muscle performance during energy-deficit training and has decades of safety data. On a reduced-calorie protocol this is the cheapest insurance for the lean mass you are trying to keep.
- Multivitamin (micronutrient density):
- A broad-spectrum multivitamin daily covers the micronutrient gaps from eating less overall. Focus on vitamin D, B12, iron (especially in women), and zinc — nutrients whose dietary sources shrink on reduced food volume.
AMPLIFY — GI microbiome (modest upside)
Slowed gastric emptying gives gut bacteria more time with each meal — a prebiotic and probiotic context is the natural complement, though evidence here is class-general, not liraglutide-specific.
- Fermented foods + probiotics:
- Daily fermented foods (yogurt, kefir, sauerkraut, kimchi) or a broad-spectrum probiotic (10–50 billion CFU) support gut diversity. The longer transit time from GLP-1-slowed digestion gives probiotics extended exposure — a passive upside of the mechanism.
- Prebiotic fiber:
- Inulin or FOS-containing foods (chicory root, garlic, onion, asparagus) 5–10 g/day feeds the beneficial bacterial species and promotes butyrate production. Pairs with the fiber recommendation from the constipation card — the same fiber serves both purposes.
Combinations + timing
Stacking notes + timing windows
Liraglutide is a GLP-1 receptor agonist. Before reaching for a stack, the first question is: does the partner compound activate the same receptor? If yes — same lever, not a stack. The useful pairings are those that add a different axis of appetite or metabolic control, or that directly address liraglutide's known weak points (lean-mass loss, daily-injection burden).
Mechanistically reasoned combinations — not tested head-to-head with liraglutide. In practice, the decision to add a partner to liraglutide often means switching to a more potent agent rather than stacking; these are the combinations where staying on liraglutide and adding something new makes sense.
Liraglutide + Cagrilintide (the non-overlapping axis)
Cagrilintide is an amylin analog — a different gut-hormone receptor, a different satiety pathway. This is the logic behind CagriSema (cagrilintide + semaglutide), applied here to liraglutide.
- Why it works:
- Amylin (signaling through the CGRP-related amylin receptor in the brainstem) acts on a different neural circuit than GLP-1. Amylin primarily slows gastric emptying and signals satiety via the area postrema; GLP-1 acts via the nucleus tractus solitarius and hypothalamic pathways. Two separate brakes, not the same one pushed twice.
- The protocol:
- Liraglutide at the prescribed daily dose (0.6 mg escalating to 1.8–3.0 mg per the titration card above) + cagrilintide subcutaneously, typically 0.3 mg once weekly escalating to 1.2–2.4 mg/week (investigational doses from the SCALE-CAMEO / CagriSema trials). Cagrilintide's weekly dosing sits alongside liraglutide's daily schedule.
- Outcome:
- The combination targets two independent satiety axes — the incretin axis (GLP-1) and the amylin axis — and is the mechanistic basis for the significant efficacy step-up seen in CagriSema trials. In practice this is a research-level combination; the existing CagriSema trials used semaglutide as the GLP-1 component, not liraglutide.
Liraglutide + Ipamorelin / CJC-1295 (lean-mass preservation)
The GH secretagogue pairing targets liraglutide's biggest weakness: the lean-mass loss that comes with GLP-1-driven caloric restriction.
- Why it works:
- Ipamorelin (a selective GHRP) and CJC-1295 (a GHRH analog) stimulate GH pulses, which promote fat oxidation and lean-mass preservation during caloric deficit. They act on the somatotropic axis — completely separate from the GLP-1 receptor. Adding a GH secretagogue while in GLP-1-driven restriction is the explicit counter to muscle loss on a prolonged daily protocol.
- The protocol:
- Liraglutide at the daily prescribed dose + ipamorelin 100–300 mcg subcutaneously at bedtime (or CJC-1295 DAC 2 mg weekly SC, or the non-DAC form 100 mcg 2–3× daily). The GH pulse timing (bedtime for ipamorelin) is independent of liraglutide's any-time daily injection.
- Outcome:
- The combination users reach for when weight loss is proceeding but body composition (fat vs muscle ratio) matters — a longer liraglutide course where lean mass preservation becomes the primary goal.
Why semaglutide or tirzepatide are NOT stack partners
A common question: can I add semaglutide or tirzepatide to liraglutide to boost efficacy? No — this is the same-lever problem.
- Same receptor:
- Semaglutide is also a GLP-1 receptor agonist. Two GLP-1 agonists together do not double the effect — they compete for the same receptor. The result is not more potency; it is overlapping side-effect risk and no added mechanism.
- Tirzepatide is GLP-1 + GIP:
- Tirzepatide adds a GIP axis, but its GLP-1 component is already saturating the receptor more potently than liraglutide. Adding liraglutide alongside tirzepatide is still redundant on the GLP-1 axis.
- The correct move:
- If liraglutide's effect is insufficient, the right decision is switching to semaglutide or tirzepatide — not stacking. Daily injection + lower efficacy + a second injectable is not a protocol; it is a reason to switch agents. The weekly drugs' efficacy advantage is large enough (roughly 2× on weight loss) that switching is almost always the better clinical decision.
Reconstitution math
Reconstitution calculator
Reconstitution calculator
Calculated for a 1 mL U-100 insulin syringe (100 units/mL).
Units per dose
72
Draw to this mark on a U-100 syringe
- Volume per dose
- 0.72 mL
- Doses per vial
- 2
- Concentration
- 2.5 mg/mL
One vial lasts
- Daily
- 2 days
- Every other day
- 5 days
- 5×/week
- 3 days
- Large draw (72 units). Double-check the vial size and dose — a mcg/mg mix-up produces values like this.
Research use only. Not for human consumption. Outputs are reference values based on research literature — verify all measurements independently.
From the studies
Side effects from research
Liraglutide carries an FDA boxed warning for thyroid C-cell tumors: in rodents it caused dose- and duration-dependent thyroid C-cell tumors (adenomas and carcinomas), and it is unknown whether it causes these tumors, including medullary thyroid carcinoma (MTC), in humans. It is contraindicated in people with a personal or family history of MTC or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
The most common adverse effects are gastrointestinal — nausea, diarrhea, vomiting, constipation, dyspepsia, and decreased appetite — which are dose-related and worst during titration. Other labeled warnings include pancreatitis (discontinue if suspected), gallbladder disease (more prominent at the 3.0 mg Saxenda dose), acute kidney injury from dehydration during heavy GI symptoms, increased heart rate, and hypoglycemia when combined with insulin or sulfonylureas. Saxenda's label also notes monitoring for suicidal ideation.
The same two honesty points that apply across the class apply here: a fraction of the weight lost is lean (muscle) mass rather than fat, and weight is regained after stopping, so the benefit depends on continued use rather than being locked in. None of this makes the drug unsafe in supervised use — it is approved and widely prescribed — but these are the trade-offs an honest summary has to state.
As reported in literature
Research dosing ranges
These are the doses tested in the major published trials, shown separately so the trial evidence is never mistaken for a recommended regimen. Liraglutide's evidence base is large, randomized, and human — landmark cardiovascular-outcome and weight-loss trials. All were given as the approved subcutaneous (under-the-skin) once-daily form under medical supervision.
| Dose | Route | Model | Outcome | Sources: |
|---|---|---|---|---|
| 1.8 mg (or max tolerated) | SC daily (~3.8 yr) | Human (LEADER, T2D high CV risk, n=9,340) | Reduced major cardiac events, plus CV and all-cause mortality, vs placebo | PMID 27295427 |
| 3.0 mg | SC daily (56 wk) | Human (SCALE, obesity, no diabetes, n=3,731) | Weight −8.4 kg (~7.9%) vs −2.8 kg placebo; ≥5% loss in 63.2% vs 27.1% | PMID 26132939 |
| 1.8 mg | SC daily (26 wk) | Human (LEAD-6, T2D, vs exenatide twice daily) | HbA1c −1.12% vs exenatide −0.79% (Δ −0.33%, p<0.0001); HbA1c <7% in 54% vs 43% | PMID 19515413 |
Quick answers
Frequently asked
What is liraglutide?
It is an FDA-approved GLP-1 receptor agonist — a copy of the gut hormone GLP-1, and the first-generation predecessor to today's weekly drugs. It is sold as Victoza for type 2 diabetes and Saxenda for weight management, and it lowers blood sugar and reduces appetite by activating the GLP-1 receptor. It is injected once daily.
How is liraglutide different from semaglutide?
They work through the same receptor and the same four mechanisms — the difference is pharmacokinetic. Liraglutide's shorter ~13-hour half-life means a daily injection, whereas semaglutide lasts about a week and is dosed weekly. Liraglutide also produces less weight loss, so it has largely been superseded by the newer weekly agents.
How much weight does liraglutide cause in trials?
In the SCALE obesity trial, the 3.0 mg daily dose (Saxenda) produced about 7.9% mean weight loss (−8.4 kg) over 56 weeks, versus about 2.6% on placebo, with 63.2% of participants losing at least 5%. That is meaningfully less than semaglutide (~15%) or tirzepatide (~20%+) in their pivotal trials.
Why does liraglutide have to be injected daily?
Its half-life is only about 13 hours. The C16 fatty-acid chain that binds it to blood albumin extends its action to roughly half a day — enough for once-daily dosing, but not the full week that the newer drugs' longer chains and optimized albumin binding achieve. Daily injection is the main practical drawback versus weekly agents.
Is liraglutide banned in sport?
As of the 2026 WADA list, the GLP-1 class is on the Monitoring Program (tracked but not prohibited, with no sanctions). Semaglutide and tirzepatide are named individually; liraglutide is not separately named. One secondary source incorrectly claims a ban — the best-supported conclusion from WADA's own communications is that liraglutide is currently permitted, with the class under monitoring.
Why is liraglutide still used if newer drugs are stronger?
It was historically pivotal — the LEADER trial first showed a GLP-1 drug reduces cardiovascular events — and it remains clinically useful. Since US generics launched in December 2024, it is also cheaper, which matters for cost-sensitive or access-limited situations even though the weekly drugs are more effective.
Primary sources
References
- PubChem CID 16134956PubChem CID 16134956 (Liraglutide)
- DailyMed (Victoza)DailyMed — Victoza (liraglutide) label
- DailyMed (Saxenda)DailyMed — Saxenda (liraglutide) label
- PMID 27295427Marso et al., NEJM 2016 (LEADER, CV outcomes)
- PMID 26132939Pi-Sunyer et al., NEJM 2015 (SCALE, obesity)
- PMID 19515413Buse et al., Lancet 2009 (LEAD-6, vs exenatide)
- WADA 2026WADA 2026 Monitoring Program (GLP-1 class monitored, not prohibited)
Research use only · Not medical advice · Updated 2026-06-01