# Retatrutide dosage & reconstitution (30 mg vial)

Retatrutide dosage: calculations for a 30 mg vial use the same amounts described in the literature. Adding 3 mL of bacteriostatic water produces 10 mg/mL, so each U-100 unit contains 100 mcg.

- **Vial contents:** 30 mg Retatrutide
- **Final volume:** 3 mL
- **Concentration:** 10 mg/mL
- **One U-100 unit:** 100 mcg in 0.01 mL

## Dosing & Reconstitution Guide
Educational guide for reconstitution and weekly dosing

### Phase 2 Trial Schedule (3 mL = ~10 mg/mL)

| Study phase | Weekly dose | Units per injection (mL) |
|---|---|---|
| Weeks 1 to 4 | 2 mg (2000 mcg) | 20 units (0.20 mL) |
| Weeks 5 to 8 | 4 mg (4000 mcg) | 40 units (0.40 mL) |
| Weeks 9 to 12 | 8 mg (8000 mcg) | 80 units (0.80 mL) |
| Weeks 13+ | 12 mg (12000 mcg) | Split: 2 × 60 units (0.60 mL each) |

Frequency: Once weekly, subcutaneously, at a consistent time.

### Reconstitution Steps

1. Draw 3 mL of bacteriostatic water with a sterile syringe.
2. Inject slowly down the vial wall; avoid shaking to prevent foaming.
3. Gently swirl or roll until fully dissolved (clear solution).
4. Label with the reconstitution date and refrigerate at 2–8 °C, protected from light; use within 4 weeks.

### Phase 3 Trial Schedule (3 mL = ~10 mg/mL)

| Study phase | Weekly dose | Units per injection (mL) |
|---|---|---|
| Weeks 1 to 4 | 2 mg (2000 mcg) | 20 units (0.20 mL) |
| Weeks 5 to 8 | 4 mg (4000 mcg) | 40 units (0.40 mL) |
| Weeks 9 to 12 | 6 mg (6000 mcg) | 60 units (0.60 mL) |
| Weeks 13 to 16 | 9 mg (9000 mcg) | 90 units (0.90 mL) |
| Weeks 17+ | 12 mg (12000 mcg) | Split: 2 × 60 units (0.60 mL each) |

Frequency: Once weekly, subcutaneously, at a consistent time.

Important: this guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.

## U-100 Conversion Table

| U-100 units | Volume | Contains | Yield per vial |
|---|---|---|---|
| 2 | 0.02 mL | 200 mcg | 150 injections |
| 5 | 0.05 mL | 500 mcg | 60 injections |
| 10 | 0.10 mL | 1 mg (1000 mcg) | 30 injections |
| 20 | 0.20 mL | 2 mg (2000 mcg) | 15 injections |
| 30 | 0.30 mL | 3 mg (3000 mcg) | 10 injections |
| 50 | 0.50 mL | 5 mg (5000 mcg) | 6 injections |
| 100 | 1.00 mL | 10 mg (10000 mcg) | 3 injections |

## Supplies Needed

**Retatrutide vials (30 mg each)**
- Phase 2 Trial Schedule, 12 weeks: Minimum 2 vials (56 mg required).
- Phase 2 Trial Schedule, 24 weeks: Minimum 7 vials (200 mg required).
- Phase 3 Trial Schedule, 12 weeks: Minimum 2 vials (48 mg required).
- Phase 3 Trial Schedule, 24 weeks: Minimum 6 vials (180 mg required).

**U-100 syringes (1 mL)**
- Phase 2 Trial Schedule, 12 weeks: 12 new syringes for 12 injections.
- Phase 2 Trial Schedule, 24 weeks: 36 new syringes for 24 injections.
- Phase 3 Trial Schedule, 12 weeks: 12 new syringes for 12 injections.
- Phase 3 Trial Schedule, 24 weeks: 32 new syringes for 24 injections.

**Bacteriostatic water**
- Phase 2 Trial Schedule, 12 weeks: 6 mL total (3 mL per vial) → 2 × 3 mL vials.
- Phase 2 Trial Schedule, 24 weeks: 21 mL total (3 mL per vial) → 7 × 3 mL vials.
- Phase 3 Trial Schedule, 12 weeks: 6 mL total (3 mL per vial) → 2 × 3 mL vials.
- Phase 3 Trial Schedule, 24 weeks: 18 mL total (3 mL per vial) → 6 × 3 mL vials.

**Alcohol swabs**
- Phase 2 Trial Schedule, 12 weeks: 24 minimum; one box of 100 covers the calculation.
- Phase 2 Trial Schedule, 24 weeks: 72 minimum; one box of 100 covers the calculation.
- Phase 3 Trial Schedule, 12 weeks: 24 minimum; one box of 100 covers the calculation.
- Phase 3 Trial Schedule, 24 weeks: 64 minimum; one box of 100 covers the calculation.

## Storage Instructions

- Lyophilized (unopened): −20 °C for long-term storage; 2–8 °C if used within weeks. Protected from light.
- Reconstituted: 2–8 °C, do not freeze. Use within the documented period (typically up to 4 weeks with bacteriostatic water).
- Handling: do not shake; avoid temperature cycling; label with date and concentration.
- Discard: cloudy solutions, particulates or expired preparations are discarded.

## How This Works

Retatrutide (LY3437943) represents the frontier of metabolic pharmacology as the first triple agonist combining synchronized activation of GIP, GLP-1, and glucagon receptors. This acylated synthetic peptide (MW: ~5960 Da) incorporates: Innovative Molecular Design: Base structure: optimized sequence of the human glucagon peptide Strategic modifications for balanced tri-agonist activity C18-C20 acyl chain at a specific lysine residue (albumin binding >98%) Hydrophilic spacer for serum stability Resistance to DPP-4 and neprilysin degradation Triple Synergistic Mechanism of Action: GIP-R Activation (Insulinotropic Polypeptide): Glucose-dependent insulin secretion potentiation Lipid metabolism modulation in white adipocytes Anti-inflammatory effect in adipose tissue CNS neuroprotection GLP-1R Activation (Glucagon-Like Peptide-1): Insulin secretion + glucagon suppression Gastric emptying delay (75% reduction) Appetite suppression via hypothalamic nuclei Preservation of pancreatic β-cell mass Glucagon Receptor (GCGR) Activation: Paradoxical effect Increase in energy consumption 15-20% Hepatic lipolysis: mobilization of visceral/ectopic fat Thermogenesis in brown adipose tissue (BAT)…

## Research FAQ

**How does Retatrutide justify the inclusion of glucagon activity?** A: Paradoxically, glucagon promotes weight loss by increasing energy expenditure by 15–20% and hepatic lipolysis, while GIP/GLP-1 prevent hyperglycemia. This unique synergy cannot be achieved with dual agonists.
**Is it safe in models with liver impairment?** A: Studies show improved liver function (↓ ALT/AST 40%, reduction in fibrosis from F3 to F1) in experimental NASH. Glucagon activation increases hepatic β-oxidation without toxicity (Sanchez-Garrido et al., 2023).
**What is the optimal protocol to assess BAT thermogenesis?** PET-CT with ¹⁸F-FDG after controlled cold exposure (16-18°C, 2h); supraclavicular tissue biopsy for UCP1/PGC-1α analysis; infrared thermography of the interscapular region; 24h indirect calorimetry.
**Therapeutic window versus adverse effects?** A: Wide therapeutic range: effective doses of 0.1–0.5 mg/kg in rodents show excellent tolerability. Transient nausea (first week) in 15–25% cases; resolves spontaneously. Monitor cardiac function at supratherapeutic doses (>3x).
**Direct comparison with bariatric surgery in models?** A: Retatrutide 12 mg (replica 85-90%) provides metabolic benefits comparable to those of Roux-en-Y gastric bypass without surgery: comparable weight loss, similar resolution of diabetes (80% vs. 85%), and equivalent improvement in lipid profile.

## References

1. Jastreboff AM et al. N Engl J Med 2023;389(6):514-526. PMID 37355123
2. Jastreboff AM, et al. (2023) “Triple G Protein-Coupled Receptor Agonist Retatrutide for Obesity” – The New England Journal of Medicine 389(6):514-526. [PubMed: 37355123]
3. Rosenstock J, et al. (2023) “Retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in type 2 diabetes” – The New England Journal of Medicine 389(6):503-513. [PubMed: 37272513]
4. Sanchez-Garrido MA, et al. (2023) “GLP-1/glucagon receptor co-agonism for the treatment of obesity” – Diabetology 66(7):1281-1294. [PubMed: 37093254]
5. Coskun T, et al. (2022) “LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist” – Cell Metabolism 34(9):1234-1247. [PubMed: 35952662]
6. Eli Lilly Research (2023) “Pharmacology and efficacy of retatrutide” – Diabetes Obes Metab 25(4):944-956.

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Source: https://protocolopeptidos.com/en/compuestos/retatrutide-30mg · Important: this guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.