Spartan Peptides LLC
All dosage protocols

Retatrutide dosage chart

30 mg Vial

Retatrutide is a multi-receptor peptide that targets GIP, GLP-1, and glucagon receptors to support weight management, appetite control, metabolic health, and improved insulin sensitivity. Spartan Peptides protocol: mix 30mg Retatrutide with 3mL BAC water for 10mg per mL — all three vial strengths dose identically.

Mixing guide
Mix 30MG Retatrutide with 3mL BAC water.
Concentration
10 mg/mL (10 units = 1mg, 1 unit = 0.1mg)
Recommended dosage
Starting at 0.5mg, up to 12mg
Injection frequency
Once weekly — same day each week.
Syringe
Use an insulin syringe (U-100) for accurate dosing. 1 unit = 0.01 mL.
Storage
Store reconstituted vial refrigerated at 2–8 °C, protected from light. Do not freeze.
Dosing schedule
1 injection per week, 7 days apart. Hold titration steps for the listed number of weeks before increasing.

Retatrutide dosing guide (30mg / 3mL BAC water)

Units (insulin syringe)MG (approximate)
5 units0.5mg
10 units1mg
15 units1.5mg
20 units2mg
25 units2.5mg
30 units3mg
40 units4mg
50 units5mg
60 units6mg
75 units7.5mg
100 units10mg
120 units12mg

Reconstitution steps

  1. 1Draw 3mL of bacteriostatic water into a sterile syringe.
  2. 2Inject the water slowly down the inside wall of the 30MG Retatrutide vial.
  3. 3Swirl gently until fully dissolved — do not shake.
  4. 4Use a U-100 insulin syringe for accurate dosing.
  5. 5Store reconstituted solution refrigerated at 2–8 °C, protected from light.

Dosing Cycle & Timing

This compound follows a once-weekly schedule, not the 5 days on / 2 days off cycle used for daily peptides.

  • Frequency: once weekly — one injection every 7 days.
  • Pick a fixed dosing day (for example every Sunday) and keep it consistent week to week.
  • If a dose day is missed, administer within 48 hours; otherwise skip it and resume the normal day.
  • Do not split the weekly amount into daily doses — GLP-1 compounds have a long half-life.
  • Stay at each titration step for the full number of weeks shown in the schedule table before stepping up.

Spartan Peptides Official Protocol

All doses are once weekly.

  • Mixing guide: mix 30MG Retatrutide with 3mL BAC water.
  • Concentration after mixing: 10 mg/mL (10 units = 1mg, 1 unit = 0.1mg).
  • Recommended dosage: Starting at 0.5mg, up to 12mg.
  • Injection frequency: once weekly.
  • Use an insulin syringe (U-100) for accurate dosing.

Reported Research Focus

Research purposes only. Premium quality. Built on legacy. Backed by science.

  • Supports weight loss*
  • Supports appetite suppression*
  • Improves metabolic health*
  • Enhances insulin sensitivity*

Important Notes

Practical considerations for consistency and safety.

  • Use new sterile insulin syringes for each injection; dispose in a sharps container.
  • Rotate injection sites (abdomen, thighs, upper arms) systematically to reduce local irritation and lipohypertrophy.
  • For volumes >1.0 mL, split into 2 separate injections at different sites for better absorption.
  • Inject slowly; 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; never skip escalation steps.

How This Works

Retatrutide’s unique mechanism of action stems from its triple-agonist design. By activating GLP-1 and GIP receptors, it enhances insulin secretion (when glucose is present) and suppresses appetite, similar to existing incretin therapies. Additionally, Retatrutide’s glucagon receptor agonism raises metabolic rate and promotes energy expenditure, further amplifying fat burning and weight loss beyond GLP-1/GIP effects alone. The peptide is engineered with a fatty-acid moiety to extend its circulation time (half-life ~6 days), allowing for once-weekly dosing. The combined hormonal activation leads to reduced calorie intake, increased satiety, and enhanced lipid oxidation, yielding potent weight loss and glycemic control. Preclinical studies confirmed that adding glucagon activity helps counteract the body’s adaptive slowing of metabolism during weight loss. In essence, Retatrutide tackles three metabolic pathways at once, resulting in greater efficacy in lowering blood glucose and body fat than single- or dual-agonist therapies.

Clinical Benefits & Side Effects

Observations from Phase 2 human clinical trials.

  • Exceptional weight loss: Patients with obesity (without diabetes) lost an average of 22–24% of body weight at 48 weeks on 8–12 mg doses.
  • Glycemic control: In type 2 diabetes patients, HbA1c dropped by 1.3–2.0% (from ~8.0% to ~6.0%) with 4–12 mg doses; ~82% reached HbA1c ≤6.5%.
  • Cardiometabolic improvements: Reductions in blood pressure, LDL cholesterol, waist circumference, and liver fat content (>80% resolution of hepatic steatosis on high doses).
  • Universal response: 100% of participants on 8–12 mg achieved at least 5% weight reduction.
  • Gastrointestinal symptoms: Most common adverse effects were mild-to-moderate nausea, vomiting, and diarrhea, occurring primarily during dose escalation.
  • Side effects were dose-dependent and transient; gradual titration (4-week intervals) significantly reduced GI discomfort compared to rapid escalation.
  • No severe hypoglycemia or serious treatment-related adverse events reported in trials.
  • Safety profile comparable to GLP-1 agonists when properly titrated.

Lifestyle Factors

Complementary strategies for optimal metabolic outcomes.

  • Maintain a balanced, protein-forward diet with adequate micronutrients to support lean mass during weight loss.
  • Combine resistance training (2–3×/week) with regular aerobic activity to preserve muscle and enhance metabolic adaptations.
  • Prioritize sleep (7–9 hours) and stress management to support adherence and hormonal balance.
  • Stay well-hydrated and monitor for signs of dehydration, especially during GI side effects.
  • Work with healthcare providers to monitor metabolic markers (HbA1c, lipids, liver function) throughout the protocol.

Injection Technique

Subcutaneous injection guidance from clinical best-practice resources.

  • Clean the vial stopper and injection site with alcohol; allow to dry completely.
  • Pinch a skinfold; insert the needle at 45–90° into subcutaneous tissue.
  • Do not aspirate for subcutaneous injections; inject slowly and steadily.
  • For volumes >1.0 mL, split into 2 injections at different sites (e.g., left and right abdomen).
  • Rotate sites systematically (abdomen preferred; also thighs, upper arms) to avoid lipohypertrophy.
  • Wait a few seconds after injecting before withdrawing needle to ensure full dose delivery.
  • Dispose of used syringes immediately in an FDA-approved sharps container.

Important Note

This content is intended for therapeutic educational purposes only and does not constitute medical advice, diagnosis, or treatment. Retatrutide is not FDA-approved and is available only for research purposes. All information presented is based on published clinical trial data and is not intended to encourage off-label use.

Supplies needed

Plan covers the full 12-week protocol at the lowest listed starting dose: 0.5 mg per dose, once weekly (12 administrations in total), using 30 mg vials. After mixing with 3 mL, the concentration is 10 mg/mL and each dose requires 0.05 mL total.

Retatrutide vials (30 mg each)

Vials are rounded up only after calculating the whole protocol: ceil(6 ÷ 30) = 1. Usable peptide remaining in an opened vial carries forward to the next dose.

Full protocol (12 weeks)
1 vial (6 mg needed ÷ 30 mg)

Insulin syringes (U-100, 1 mL)

One fresh syringe per administration.

Full protocol (12 weeks)
12 syringes

Bacteriostatic water (10 mL bottles)

Use 3 mL per vial for reconstitution (1 × 3 mL = 3 mL).

Full protocol (12 weeks)
1 × 10 mL bottle

Alcohol swabs

One for the vial stopper per draw + one for each injection site (once weekly).

Full protocol (12 weeks)
24 swabs

Retatrutide dosage FAQs

How do you reconstitute a 30 mg Vial vial of Retatrutide?

Add bacteriostatic water slowly down the inside wall of the 30 mg Vial Retatrutide vial, swirl gently until clear, and use the reconstitution calculator to convert your chosen water volume into syringe units.

What is a typical Retatrutide dose?

Recommended dosage: Starting at 0.5mg, up to 12mg. Figures are research reference values only.

How often is Retatrutide administered in research protocols?

Injection frequency: Once weekly — same day each week.

What concentration does reconstituted Retatrutide end up at?

Concentration: 10 mg/mL (10 units = 1mg, 1 unit = 0.1mg). On any insulin syringe 1 unit = 0.01 mL, so unit counts convert directly across brands.

What does the Retatrutide retatrutide dosing guide (30mg / 3ml bac water) look like?

5 units — 0.5mg; 10 units — 1mg; 15 units — 1.5mg; 20 units — 2mg. The full table above lists every step with matching syringe units.

What are the mixing steps for Retatrutide?

Draw 3mL of bacteriostatic water into a sterile syringe. Inject the water slowly down the inside wall of the 30MG Retatrutide vial. Swirl gently until fully dissolved — do not shake.

How should reconstituted Retatrutide be stored?

Storage: Store reconstituted vial refrigerated at 2–8 °C, protected from light. Do not freeze..

How many insulin syringe units equal a Retatrutide dose?

Units depend on the water volume you used. Divide your target dose by the vial concentration to get millilitres, then multiply by 100 — 1 unit on a U-100 insulin syringe is 0.01 mL. The Spartan Peptides reconstitution calculator does this conversion for you.

Is Retatrutide approved for human use?

No. Retatrutide is sold and referenced strictly as a research chemical. Nothing on this page is medical advice and the material is not for human consumption.

Educational and research information only. Not medical advice, not for human consumption. Values are reference figures — always verify your own math with the reconstitution calculator.

On any insulin syringe, 1 unit = 0.01 mL, so unit counts above hold across brands.