Peptide Comparison
LiraglutidevsRetatrutide
FDA-approved once-daily GLP-1 receptor agonist (Victoza/Saxenda) that reduces HbA1c by 0.9–1.6%, promotes 5–10% body weight loss, and demonstrated a 13% reduction in major adverse cardiovascular events in the landmark LEADER trial of 9,340 patients
The world's first triple-action weight loss peptide that simultaneously activates three hormone receptors—GIP, GLP-1, and glucagon—delivering unprecedented weight loss results of up to 24% body weight in clinical trials.
At a Glance
Quick
comparison
Dose Range
Liraglutide
0.6–3.0 mg
Retatrutide
1–12 mg
Frequency
Liraglutide
Once daily
Retatrutide
Once weekly
Administration
Liraglutide
Subcutaneous injection
Retatrutide
Subcutaneous injection
Cycle Length
Liraglutide
Ongoing/indefinite
Retatrutide
12+ weeks
Onset Speed
Liraglutide
Gradual (3-4 weeks)
Retatrutide
Moderate (1-2 weeks)
Evidence Level
Liraglutide
Strong human trials (Phase 3 or FDA approved)
Retatrutide
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Weight Management
Metabolic
Healing & Recovery
Weight Loss Power
Metabolic Health
Appetite Control
Technical Data
Compound
specifications
Liraglutide
Molecular Formula
C172H265N43O51
Molecular Weight
3,751 Da
Half-Life
~13 hours (enabling once-daily dosing); Tmax 8–12 hours; steady state in 3–5 days
Bioavailability
~55% after subcutaneous injection; >98% plasma protein binding to albumin via C16 fatty acid moiety
CAS Number
204656-20-2
Retatrutide
Molecular Formula
C221H342N46O68
Molecular Weight
4731 g/mol
Half-Life
~6 days (allows once-weekly dosing)
Bioavailability
High via subcutaneous injection
CAS Number
2381089-83-2
Protocols
Dosing
tiers
Liraglutide
Retatrutide
Applications
Best
suited for
Liraglutide
Type 2 diabetes patients with HbA1c >7% requiring both glycemic control and weight management
Liraglutide is particularly well-suited for individuals focused on type 2 diabetes patients with hba1c >7% requiring both glycemic control and weight management. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Obese individuals (BMI ≥30) or overweight (BMI ≥27) with weight-related comorbidities seeking FDA-approved pharmacotherapy
Liraglutide is particularly well-suited for individuals focused on obese individuals (bmi ≥30) or overweight (bmi ≥27) with weight-related comorbidities seeking fda-approved pharmacotherapy. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Patients with established cardiovascular disease or high cardiovascular risk seeking cardioprotective diabetes therapy
Liraglutide is particularly well-suited for individuals focused on patients with established cardiovascular disease or high cardiovascular risk seeking cardioprotective diabetes therapy. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Patients on metformin requiring add-on therapy with favorable weight and cardiovascular profile
Liraglutide is particularly well-suited for individuals focused on patients on metformin requiring add-on therapy with favorable weight and cardiovascular profile. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Retatrutide
Significant Obesity Management
If you need to lose a substantial amount of weight, retatrutide is showing unprecedented results. Phase 2 trials demonstrated average weight loss of 24% at the highest dose—that's nearly 60 pounds for someone weighing 250 lbs. No other medication has matched this.
Type 2 Diabetes with Obesity
Retatrutide tackles both problems at once. It dramatically improves blood sugar control (HbA1c reductions of up to 2%) while delivering major weight loss. The dual benefit makes it especially valuable for diabetics struggling with weight.
Metabolic Syndrome Warriors
If you're dealing with the cluster of issues that includes high blood sugar, excess belly fat, abnormal cholesterol, and high blood pressure, retatrutide's triple mechanism attacks multiple aspects of metabolic dysfunction simultaneously.
Fatty Liver Disease (MASLD)
Early research shows retatrutide may significantly reduce liver fat. For people with non-alcoholic fatty liver disease, this peptide offers hope through weight loss plus direct metabolic improvements that benefit liver health.
Safety Profile
Side
effects
Liraglutide
Common
- Nausea
- Diarrhea
- Vomiting
- Decreased appetite and headache
Uncommon
- Injection site reactions
Serious
- Acute pancreatitis
- Gallbladder disease
Retatrutide
Common
- Nausea
- Diarrhea
- Constipation
- Decreased appetite
Uncommon
- Increased heart rate
- Injection site reactions
Serious
- Pancreatitis
- Gallbladder problems
Research Status
Safety
& evidence
Liraglutide
Evidence Level
Strong human trials (Phase 3 or FDA approved)
FDA Status
FDA approved for this use
Safety Overview
Liraglutide (Victoza, Saxenda) is FDA-approved with extensive safety data from 15+ years of clinical use in diabetes (GLP-1 agonist) and obesity indications. Gastrointestinal side effects (nausea, vomiting, diarrhea) occur in 30-40% of patients during dose escalation but diminish significantly after 2-3 weeks of stable dosing. Black box warnings include risk of medullary thyroid carcinoma and pancreatitis, though absolute incidence remains rare. Injection site reactions are minimal. The compound shows no hepatotoxicity, nephrotoxicity, or major drug interactions at approved doses.
Contraindications
- xPersonal or family history of medullary thyroid carcinoma (MTC) — black box warning based on rodent thyroid C-cell tumor findings
- xMultiple Endocrine Neoplasia syndrome type 2 (MEN 2)
- xKnown hypersensitivity to liraglutide or any excipients
- xPregnancy (Saxenda indication) — contraindicated; effective contraception required
Retatrutide
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Retatrutide has shown a generally favorable safety profile in Phase 1 and Phase 2 clinical trials involving over 600 participants. Most side effects are gastrointestinal and tend to improve over time. The medication appears well-tolerated when doses are increased gradually. No major safety signals have emerged, but larger Phase 3 trials are still ongoing.
Contraindications
- xPersonal or family history of medullary thyroid carcinoma (MTC)
- xMultiple Endocrine Neoplasia syndrome type 2 (MEN 2)
- xPregnancy or planning to become pregnant
- xHistory of severe pancreatitis
- xKnown allergy to GLP-1 receptor agonists
Decision Guide
Which is
right for you?
Choose Liraglutide if...
- Type 2 diabetes patients with HbA1c >7% requiring both glycemic control and weight management
- Obese individuals (BMI ≥30) or overweight (BMI ≥27) with weight-related comorbidities seeking FDA-approved pharmacotherapy
- Patients with established cardiovascular disease or high cardiovascular risk seeking cardioprotective diabetes therapy
- Patients on metformin requiring add-on therapy with favorable weight and cardiovascular profile
Choose Retatrutide if...
- Significant weight loss
- Type 2 diabetes management
- Metabolic health improvement
- Body composition optimization