SingleMetabolic / GLP-1

Retatrutide 20mg

First-in-class GLP-1/GIP/glucagon triple agonist studied in metabolic research for weight regulation and glycemic control.

Mechanism

Simultaneously engages GLP-1, GIP, and glucagon receptors to synergistically curb appetite, improve glycemic regulation, and enhance energy expenditure.

Dosing

Protocols document an introductory dose of 2 mg administered once weekly for the initial four weeks.

Reconstitution

Reconstituting the 20 mg vial with 2.0 mL of bacteriostatic water yields a peptide concentration of 10 mg/mL.

Storage

Store the unmixed lyophilized vial frozen at -20 °C, and keep the reconstituted liquid refrigerated at 2–8 °C away from light for up to 2 to 4 weeks.

Mix & measure Retatrutide 20mg

Pre-filled with this protocol's recommended BAC water and documented starting dose — edit any field to run your own numbers.

Mix & measure Retatrutide 20mg

Vial strength → BAC water → target dose

Vial strength

BAC water

Target dose

Concentration10.0mg/mL

Draw volume0.200mL

On the syringe20.0units

Total doses in vial: 10.0

100u80u60u40u20u0

U-100 syringe: 100 units = 1 mL

Reconstitution math only — not dosing advice. U-100 syringe: 100 units = 1 mL. Advanced calculator →

Dosing Chart

Phase / Day(s)	Dose & Frequency	Volume (U-100 units / mL)
Weeks 1–4	2 mg once weekly	20 units (0.20 mL)
Weeks 5–8	4 mg once weekly	40 units (0.40 mL)
Weeks 9–12	8 mg once weekly	80 units (0.80 mL)
Weeks 13+	12 mg once weekly	120 units (1.20 mL)

Reconstitution Steps

1
Draw 2.0 mL of bacteriostatic water into a sterile syringe.
2
Introduce the liquid slowly down the interior glass wall of the 20 mg Retatrutide vial to prevent agitation.
3
Gently swirl or roll the vial until the lyophilized powder has completely dissolved, avoiding vigorous shaking.
4
Record the date of reconstitution and transfer the vial to refrigerated storage at 2–8 °C protected from direct light.

Supplies Needed

Peptide Vial

20 mg lyophilized Retatrutide powder

Insulin Syringes (U-100)

1 mL sterile syringes for weekly draw and administration

Bacteriostatic Water

2.0 mL diluent for reconstituting the lyophilized peptide

Alcohol Swabs

Sanitization of vial stopper and subcutaneous injection site

Why researchers study it

Investigation of substantial body-weight reduction

Appetite modulation and caloric intake signaling

Glycemic regulation and HbA1c dynamics in diabetes models

Hepatic lipid clearance and cardiometabolic parameters

These describe what is being studied, not proven benefits, approved uses, or promised results.

Overview

Retatrutide is an investigational synthetic peptide designed to act as a unimolecular triple agonist across three critical metabolic endocrine pathways: GLP-1, GIP, and glucagon receptors. By coordinating signaling across these distinct targets, it has demonstrated unprecedented efficacy in preclinical models and clinical trials focused on severe adiposity and type 2 diabetes management. In human clinical trials, the compound has displayed an extended biological half-life of approximately six days, facilitating a once-weekly dosing schedule. The concurrent engagement of glucagon receptors promotes energy expenditure and hepatic lipid turnover, complementing the satiety, delayed gastric emptying, and insulinotropic effects driven by the incretin components GLP-1 and GIP. Research implementations prioritize conservative initial dosing and systematic multi-week escalation intervals. This titration approach maintains tolerability while allowing experimental models to adapt progressively to multi-hormone metabolic signaling.

References

1.Jastreboff et al., New England Journal of Medicine, 2023 — Triple-Hormone-Receptor Agonist Retatrutide for Obesity
2.JAMA Network, 2023 — Retatrutide Phase 2 Obesity Trial: detailed efficacy and safety data
3.Rosenstock et al., The Lancet, 2023 — Retatrutide in type 2 diabetes: Phase 2 trial
4.PubMed / NEJM, 2023 — Retatrutide dosing and tolerability: starting at 2 mg vs 4 mg reduces GI adverse events
5.Metabolites (PMC), 2025 — Retatrutide—A Game Changer in Obesity Pharmacotherapy
6.Baylor University Medical Center Proceedings (PMC), 2025 — Efficacy and safety of retatrutide for obesity: meta-analysis of RCTs
7.PubMed, 2025 — Meta-analysis: Retatrutide achieves ~14% greater weight reduction vs placebo with no increase in adverse events
8.Molecular Metabolism, 2025 — Preclinical tri-agonist NN1706 (related compound): mechanism and pharmacokinetics
9.Nature Reviews Endocrinology, 2024 — Triple agonist therapies for obesity and diabetes: clinical landscape review