Side-by-side · Research reference

RetatrutidevsSurvodutide

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

APhase 2HUMAN-REVIEWED10/41 cited

BPhase 3HUMAN-REVIEWED25/54 cited

Retatrutide

Triple-receptor agonist · Phase 3

1–12 mgWeekly doseJastreboff 2023

24.2%Body-weight ↓Jastreboff 2023

~6 daysHalf-life (est)

SQ · Abdomen · Once weekly

Survodutide

GLP-1/Glucagon Dual Agonist · Phase 3

Once weeklyFrequency

Phase 3Development stageRubino 2026

GLP-1/GCGRDual targetZimmermann 2026

SQ · Once Weekly

01Mechanism of Action

Parameter

Retatrutide

Survodutide

Primary target

GLP-1R + GIPR + Glucagon receptor (triple agonism)Jastreboff 2023

GLP-1 receptor and glucagon receptor (GCGR)Yathindra 2026 Zimmermann 2026

Pathway

Triple-receptor activation → ↑insulin (GLP-1+GIP), ↓gastric emptying, ↑lipid handling, ↑energy expenditure (glucagon component)Jastreboff 2023

Central: CVOs → hypothalamic appetite regulation. Peripheral: GLP-1R → incretin effect; GCGR → hepatic lipid metabolism, energy expenditureZimmermann 2026 Long 2026

Downstream effect

Maximal weight loss across class. Glucagon component drives lipolysis and energy expenditure beyond GLP-1+GIP aloneJastreboff 2023

Decreased energy intake, increased energy expenditure, improved glucose homeostasis, hepatic fat reductionZimmermann 2026 Yathindra 2026

Feedback intact?

—

Origin

Synthetic peptide engineered for balanced affinity at three incretin / glucagon receptorsJastreboff 2023

—

Antibody development

—

02Dosage Protocols

Parameter

Retatrutide

Survodutide

Standard dose

12 mg / week (max efficacy)Jastreboff 2023

Phase 2 trial dose. Phase 3 dosing TBD.

Not yet disclosed (Phase 3 ongoing)

SYNCHRONIZE Phase 3 program underway.Rubino 2026

Frequency

Once weekly

Titration schedule

2 mg → 4 mg → 8 mg → 12 mg over 16 weeks

—

Evidence basis

Phase 2 trial; Phase 3 ongoingJastreboff 2023

Phase 2 RCT (obesity) · Phase 3 ongoing

Duration

Indefinite for chronic indication (presumed)

—

Reconstitution

Investigational; not commercially available

—

Timing

Any time of day

—

Half-life

~6 days (estimated from class)

—

Route

—

SubcutaneousYathindra 2026

Phase 2 findings

—

Significant weight loss and metabolic marker improvementYathindra 2026

MASH indication

—

Under investigation for MASH-cirrhosisPatil 2026 Andonie 2026

03Metabolic / Fat Loss Evidence

Parameter

Retatrutide

Survodutide

Primary fat target

—

Total body weight, visceral adipose tissue

Weight loss mechanism

—

Dual action: decreased energy intake + increased energy expenditureZimmermann 2026

Phase 2 efficacy

—

Significant weight loss demonstrated

Specific percentage not disclosed in abstracts.

Metabolic markers

—

Improvements in ALT, AST, LDL levels; significant ALT reduction (MD -22.10 vs placebo)Yathindra 2026 Abulehia 2026 Andonie 2026

MRI-PDFF reduction

—

Hepatic fat reduction demonstrated in MASH trialsAndonie 2026

Network meta-analysis

—

Favorable efficacy profile vs other glucagon receptor agonists

Hepatic requirement

—

Hepatic GCGR required for maximal weight loss and metabolic effectsLong 2026

Energy expenditure

—

Increased energy expenditure contributes to weight lossZimmermann 2026

Comparative efficacy

—

Network meta-analysis shows competitive efficacy in GRA class

04Side Effects & Safety

Parameter

Retatrutide

Survodutide

GI symptoms

Nausea, vomiting, diarrhea (very common, dose-dependent)Jastreboff 2023

Diarrhea, nausea, fatigue — class effect of GLP-1 agonists

Heart rate

↑ resting HR (3–7 bpm at 12 mg)Jastreboff 2023

—

Glucose handling

Glycemic improvement; rare hyperglycemia from glucagon component

—

Pancreatitis risk

Class warning

—

Thyroid C-cell tumours

Class warning (presumed)

—

Pregnancy / OB

Avoid (insufficient data)

—

Safety profile

—

Network meta-analysis: comparable safety to other GRAs

Serious adverse events

—

Monitored in Phase 2/3; no unique safety signals reported

Detailed SAE data pending Phase 3 completion.

Injection site reactions

—

Expected with subcutaneous administration

Glucagon-related effects

—

Potential for tachycardia, increased blood pressure — theoretical glucagon effect

Absolute Contraindications

Retatrutide

·MTC personal or family history (presumed class effect)
·Pregnancy / breastfeeding

Survodutide

·Personal or family history of medullary thyroid carcinoma (class effect)
·Multiple endocrine neoplasia syndrome type 2

Relative Contraindications

Retatrutide

·Severe gastroparesis
·History of pancreatitis
·Severe cardiovascular disease (HR signal)

Survodutide

·Severe GI disease (inflammatory bowel disease, gastroparesis)
·History of pancreatitis
·Cardiovascular disease (monitor closely for glucagon effects)

05Administration Protocol

Parameter

Retatrutide

Survodutide

1. Reconstitution

Investigational peptide. Research vials reconstituted with bacteriostatic water per label.

Specific reconstitution protocol not yet publicly disclosed. Follow manufacturer instructions upon approval.

2. Injection site

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

Subcutaneous — abdomen, thigh, or upper arm. Rotate sites weekly to minimize injection site reactions.

3. Timing

Once weekly, same day.

Once weekly, same day each week. Can be administered at any time of day, with or without meals.

4. Storage

Refrigerate 2–8 °C. Light-protected.

Store refrigerated (2–8 °C) until use. Do not freeze. Protect from light. Specific reconstituted storage duration pending labeling.

5. Needle

27–31G, 4–8 mm insulin syringe.

Subcutaneous injection with appropriate gauge needle (typically 27–31G). Use sterile technique.