Retatrutide is a multi-agonist peptide used in research settings for significant weight reduction and metabolic improvements. It is administered via weekly subcutaneous injections, with dosage typically starting low and gradually increasing over several weeks. Reconstitution involves mixing the 30 mg vial with 3.0 mL of bacteriostatic water to achieve a concentration that allows for precise dose measurements.
- Triple-agonist affecting GLP-1, GIP, and glucagon receptors.
- Achieved up to 24% body weight loss in clinical trials for obesity.
- Administered once weekly via subcutaneous injection.
- Gradual dose escalation is crucial to minimize gastrointestinal side effects.
- Available for research use only, not FDA-approved.
Reconstitution
Vial strength
30 mg
Bacteriostatic water
3 mL
Concentration
10 mg/mL
1 unit = 0.01 mL = 100 mcg on a U-100 insulin syringe
- 1Draw 3.0 mL of bacteriostatic water using a sterile syringe.
- 2Slowly inject the water down the inner wall of the Retatrutide vial to prevent foaming.
- 3Gently swirl or roll the vial until the peptide is fully dissolved; do not shake vigorously.
- 4Label the vial with the reconstitution date and refrigerate it at 2-8 °C (35.6-46.4 °F), protected from light.
- 5Utilize the reconstituted solution within 4 weeks.
Dosing schedule
| Phase | Dose | On a U-100 syringe |
|---|---|---|
| Weeks 1-4 | 2 mg | 20 units (0.20 mL) |
| Weeks 5-8 | 4 mg | 40 units (0.40 mL) |
| Weeks 9-12 | 6 mg (Standard) / 8 mg (Advanced) | 60 units (0.60 mL) / 80 units (0.80 mL) |
| Weeks 13+ | 8 mg (Standard) / 12 mg (Advanced) | 80 units (0.80 mL) / 120 units (1.20 mL) |
Protocol detail
| Start | Begin with 2 mg weekly for 4 weeks to assess individual tolerance. |
|---|---|
| Escalate | Increase the dose by 2–4 mg every 4 weeks as tolerated. |
| Target | Aim for 6–8 mg weekly for standard protocols, or up to 12 mg weekly for advanced/aggressive approaches. |
| Frequency | Administer once per week (subcutaneously) on the same day each week. |
| Cycle Length | Maintain for a minimum of 24 weeks, with trials extending up to 48 weeks. |
| Timing | Any consistent day or time is suitable; remember to rotate injection sites with each dose. |
Overview at a glance
| Goal | Support significant weight reduction and metabolic improvements through triple-receptor activation. |
|---|---|
| Schedule | Weekly subcutaneous injections for 12–48 weeks. |
| Dose Range | 2–12 mg weekly with gradual 4-week titration steps. |
| Reconstitution | 3.0 mL per 30 mg vial (~10.0 mg/mL) for accurate unit measurements. |
| Storage | Lyophilized frozen at -20 °C (-4 °F); reconstituted refrigerated at 2–8 °C (35.6–46.4 °F) for up to 4 weeks. |
How it works
Retatrutide functions as a triple-agonist, activating GLP-1, GIP, and glucagon receptors. This multi-pathway approach significantly suppresses appetite and enhances insulin secretion in the presence of glucose, while also increasing metabolic rate and energy expenditure. The glucagon agonism helps counteract the metabolic slowdown often observed during weight loss. Designed with a fatty-acid moiety, Retatrutide has an extended half-life, enabling once-weekly dosing. The combined effect results in reduced calorie intake, increased satiety, and improved fat burning, leading to potent weight loss and better glycemic control by addressing multiple components of metabolic regulation.
Reported effects
- Exceptional weight loss (average 22–24% in obesity trials)
- Significant glycemic control for type 2 diabetes (HbA1c reductions of 1.3–2.0%)
- Improved cardiometabolic markers (reduced blood pressure, LDL cholesterol, waist circumference)
- Resolution of hepatic steatosis (liver fat) in over 80% of cases with high doses
- Universal response with 100% of participants achieving at least 5% weight reduction on higher doses
Reported side effects
- Nausea (mild-to-moderate, most common)
- Vomiting (mild-to-moderate)
- Diarrhea (mild-to-moderate)
- Gastrointestinal symptoms primarily occur during dose escalation
- Side effects are dose-dependent and transient
- No severe hypoglycemia or serious treatment-related adverse events reported
Storage
Lyophilised (unmixed)
Store at -20 °C (-4 °F) or colder in dry, dark conditions for up to 24 months.
After reconstitution
Refrigerate at 2-8 °C (35.6-46.4 °F) and use within 4 weeks. For longer storage, aliquot and freeze at -20 °C, thawing only once before use.
Supplies
| Peptide vials | Recommended based on protocol length: 2 vials for 12 weeks (Standard to 6 mg or Aggressive to 8 mg), 5 vials for 24 weeks (Standard to 8 mg). |
|---|---|
| Insulin Syringes (U-100, 1 mL capacity) | 1-2 syringes per week (depending on dose); 12-24 syringes for 12 weeks, 24-48 syringes for 24 weeks. |
| Bacteriostatic Water (10 mL bottles) | Approximately 3.0 mL per vial for reconstitution; 1 x 10 mL bottle for 12 weeks, 2 x 10 mL bottles for 24 weeks. |
| Alcohol Swabs | 2-4 swabs per week; ~50 swabs for 12 weeks, ~100 swabs for 24 weeks. |
Important notes
- Use a new, sterile insulin syringe for each injection and dispose of it in a sharps container.
- Rotate injection sites (abdomen, thighs, upper arms) to prevent irritation and lipohypertrophy.
- For injection volumes exceeding 1.0 mL, split the dose into two separate injections at different sites to ensure proper absorption.
- Inject slowly and wait a few seconds before withdrawing the needle to ensure full dose delivery.
- Document weekly dose, date, and injection sites to maintain consistency.
- Gradual titration is essential to minimize gastrointestinal side effects; avoid skipping escalation steps.
Frequently asked questions
What makes Retatrutide different from other weight loss peptides?
Retatrutide is a unique 'triple-agonist,' meaning it targets three different hormonal receptors: GLP-1, GIP, and glucagon. This multi-target approach aims to provide more comprehensive effects on appetite suppression, metabolism, and energy expenditure compared to peptides that only target one or two of these pathways, leading to potentially greater weight loss and metabolic improvements.
Why is gradual dose titration recommended for Retatrutide?
Gradual dose titration, typically increasing the dose every 4 weeks, is crucial for Retatrutide to help the body adapt to the peptide's effects. This method significantly reduces the incidence and severity of gastrointestinal side effects, such as nausea, vomiting, and diarrhea, which are common when starting or increasing the dose too quickly.
How should I store Retatrutide once it's reconstituted?
After reconstituting your Retatrutide vial with bacteriostatic water, it should be stored in the refrigerator between 2-8 °C (35.6-46.4 °F) and protected from light. It is stable under these conditions for up to 4 weeks. For longer storage after reconstitution, you can aliquot the solution into smaller, single-use portions and freeze them at -20 °C, but only thaw each aliquot once before use.
Can I split a single Retatrutide dose into multiple injections?
Yes, if your weekly Retatrutide dose requires an injection volume greater than 1.0 mL, it is recommended to split the dose into two separate injections. These should be administered at different subcutaneous sites to ensure proper absorption and minimize discomfort. Remember to rotate injection sites with each dose regardless of volume.
Educational reference only. These figures summarise how Retatrutide is commonly described in research literature and supplier documentation, including the Retatrutide listing at peptidesuk4u.co.uk. They are not a prescription, not medical advice, and not a recommendation to self-administer anything.
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