Side-by-side · Research reference

GLP-1 (7-37)vsLiraglutide

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AHuman-MechanisticHUMAN-REVIEWED16/43 cited

BFDA-ApprovedFlagship14/45 cited

GLP-1 (7-37)

Incretin Hormone · Native Peptide

~2 minHalf-lifeAlavi 2021 Ding 2017

3297.7 DaMolecular weightAlavi 2021

1922Discovery year

Research use only · IV/SC in experimental settings

Liraglutide

Daily GLP-1 RA · FDA-Approved

0.6–3.0 mgDaily doseSAXENDA (liraglutide) injectio 2014

5–10%Body-weight ↓SAXENDA (liraglutide) injectio 2014

~13 hrHalf-lifeSAXENDA (liraglutide) injectio 2014

SQ · Abdomen / thigh / arm · Once daily

01Mechanism of Action

Parameter

GLP-1 (7-37)

Liraglutide

Primary target

GLP-1 receptor (class B GPCR)Koole 2015

GLP-1 receptor (GLP-1R)SAXENDA (liraglutide) injectio 2014

Pathway

GLP-1R activation → cAMP production → PKA signaling → insulin secretion (pancreatic β-cells)Lu 2025 Koole 2015

GLP-1R agonism → ↑glucose-dependent insulin, ↓glucagon, ↓gastric emptying, ↓appetiteSAXENDA (liraglutide) injectio 2014 Marso 2016

Downstream effect

Glucose-dependent insulin release, glucagon suppression, delayed gastric emptying, reduced food intakeLu 2025 Ding 2017

Glycemic improvement, modest body-weight reduction, cardiovascular event reduction in high-risk T2DMarso 2016

Feedback intact?

Yes — physiological secretion and degradation preserved

Glucose-dependent insulin release preserves physiological feedback

Origin

Endogenous peptide cleaved from proglucagon in intestinal L cells; secreted postprandially

Modified GLP-1(7-37) with Lys26 substitution (Arg34) and C-16 palmitoyl-glutamate acylation for albumin bindingSAXENDA (liraglutide) injectio 2014

Antibody development

—

02Dosage Protocols

Parameter

GLP-1 (7-37)

Liraglutide

Clinical use

None — native GLP-1 not used therapeutically

Engineered analogues (semaglutide, liraglutide) used clinically.Friedman 2024

—

Research dosing

Variable — 0.1–10 nmol/kg in animal models

Used as reference standard for analogue comparison.

—

Half-life

~2 minutes (plasma)Alavi 2021 Ding 2017

Requires continuous infusion for sustained effect.

~13 hrSAXENDA (liraglutide) injectio 2014

Modified analogues

t½ extended to 13 h (liraglutide), 165 h (semaglutide)

Via DPP-4 resistance + fatty acid acylation.

—

Standard dose (T2D, Victoza)

—

1.2–1.8 mg / daySAXENDA (liraglutide) injectio 2014

Standard dose (weight, Saxenda)

—

3.0 mg / day (after 5-week titration)SAXENDA (liraglutide) injectio 2014

Frequency

—

Once daily, same time each day

Titration schedule

—

0.6 → 1.2 → 1.8 → 2.4 → 3.0 mg over 5 weeks

Mitigates GI side effects.

Evidence basis

—

FDA-approved · Phase 3 RCTs (LEADER, SCALE)Marso 2016 SAXENDA (liraglutide) injectio 2014

Duration

—

Indefinite for chronic indication

Reconstitution

—

Pre-filled commercial pen (no reconstitution)

Timing

—

Any time of day; consistent

03Metabolic / Fat Loss Evidence

Parameter

GLP-1 (7-37)

Liraglutide

Mechanism

GLP-1R activation in hypothalamic satiety centers (arcuate nucleus) reduces food intakeLu 2025

Effect demonstrated with long-acting analogues (liraglutide).Lu 2025

—

Native GLP-1 efficacy

Minimal — rapid degradation prevents sustained appetite suppression

—

Gastric emptying

Delayed in animal models, contributing to satiety

—

Body weight impact

Not observed with native GLP-1 — requires analogue formulations

—

04Side Effects & Safety

Parameter

GLP-1 (7-37)

Liraglutide

Native GLP-1

Well-tolerated in research settings; no prolonged exposure data

—

Hypoglycemia risk

Low — insulin secretion is glucose-dependent

—

Analogue side effects

Nausea, vomiting, diarrhea (GLP-1R agonists)

Not applicable to native GLP-1 due to non-therapeutic use.

—

GLP-1 resistance

High glucose-induced PKCβ overexpression may reduce GLP-1 responsiveness in endothelial cellsPujadas 2016

—

GI symptoms

—

Nausea, vomiting, diarrhea (very common during titration)SAXENDA (liraglutide) injectio 2014

Pancreatitis risk

—

Rare; discontinue if suspected

Thyroid C-cell tumours

—

Boxed warning — contraindicated in MEN2 / MTC historySAXENDA (liraglutide) injectio 2014

Hypoglycemia

—

Low risk as monotherapy; elevated with sulfonylureas / insulin

Heart rate

—

Modest ↑ resting HR (~2-3 bpm)

Cardiovascular benefit

—

↓ MACE in high-risk T2D (LEADER trial)Marso 2016

Pregnancy / OB

—

Contraindicated

Absolute Contraindications

GLP-1 (7-37)

—

Liraglutide

·MTC personal or family history; MEN2
·Pregnancy / breastfeeding
·Hypersensitivity to liraglutide

Relative Contraindications

GLP-1 (7-37)

—

Liraglutide

·Severe gastroparesis
·History of pancreatitis
·Severe gastrointestinal disease

05Administration Protocol

Parameter

GLP-1 (7-37)

Liraglutide

1. Research use only

Native GLP-1(7-37) is not formulated for therapeutic use. Administered IV or SC in experimental protocols to study GLP-1R pharmacology and as reference standard for analogue development.

Commercial pre-filled pen, no reconstitution required.

2. Storage

Lyophilised peptide stored at -20°C or below. Reconstituted solutions should be prepared fresh and used immediately due to rapid degradation.

SQ — abdomen, thigh, or upper arm. Rotate sites.

3. Clinical alternatives

For therapeutic GLP-1R activation, use FDA-approved long-acting analogues: semaglutide (once weekly), liraglutide (once daily), dulaglutide (once weekly), or exenatide (twice daily or once weekly).

Once daily, same time each day. Take with or without food.

4. Storage

—

Refrigerate 2–8 °C unopened; room temp ≤30 °C up to 30 days after first use.

5. Needle

—

Pen-supplied 32G needle.