Retatrutide Dosage Calculator

Category: Other Health Author: Henrick Yau
- August 22, 2025
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Calculate retatrutide dosing schedules based on clinical trial protocols. Retatrutide is a novel triple-hormone receptor agonist (GIP/GLP-1/Glucagon) currently in Phase 3 trials for obesity and metabolic disorders. This calculator helps healthcare providers understand evidence-based dosing regimens.

Important: Retatrutide is investigational and not yet FDA-approved. This calculator is for educational purposes only based on published clinical trial data. Always consult current medical literature and regulatory guidelines.

Patient Information

Patient's current body weight in kilograms
Patient's height in centimeters

Dose Escalation Protocol

Clinical Considerations

Understanding Retatrutide: Clinical Trial Data & Dosing

Retatrutide (LY3437943) is a novel triple-hormone receptor agonist that targets GIP, GLP-1, and glucagon receptors. Phase 2 clinical trials have demonstrated unprecedented weight loss efficacy, with the 12 mg dose achieving mean weight reductions of up to 24.2% at 48 weeks.

Clinical Trial Dosing Protocols
  • Starting Doses: 2 mg or 4 mg weekly based on GI tolerance
  • Escalation Interval: Every 4 weeks in Phase 2 trials
  • Maintenance Doses: 4 mg, 8 mg, or 12 mg weekly
  • Escalation Strategy: Gradual dose increases to minimize GI side effects
  • Maximum Duration: 48+ weeks studied in clinical trials
Phase 2 Efficacy Results (NEJM 2023)
  • 4 mg dose: 17.1% mean weight loss at 48 weeks
  • 8 mg dose: 22.8% mean weight loss at 48 weeks
  • 12 mg dose: 24.2% mean weight loss at 48 weeks
  • ≥5% weight loss: Achieved in 92-100% of patients (doses ≥4mg)
  • ≥15% weight loss: Achieved in 60-83% of patients (doses ≥4mg)
Triple Mechanism of Action
  • GLP-1 Agonism: Delays gastric emptying, increases satiety
  • GIP Agonism: Enhances insulin sensitivity, glucose metabolism
  • Glucagon Agonism: Increases energy expenditure, hepatic fat oxidation
  • Synergistic Effects: Combined mechanisms provide superior efficacy
  • Central Effects: Hypothalamic appetite regulation
Safety Profile from Clinical Trials
  • GI Side Effects: Most common (nausea, diarrhea, vomiting)
  • Severity: Mostly mild-to-moderate, occurring during dose escalation
  • Heart Rate: Dose-dependent increases, peak at 24 weeks
  • Discontinuation: 6-16% due to adverse events vs 0% placebo
  • Serious AEs: Similar frequency to placebo (4% each group)
Special Populations & Indications
  • Type 2 Diabetes: HbA1c reductions up to 2.02% with weight loss
  • NAFLD/MASLD: Up to 82% reduction in liver fat content
  • Cardiovascular: Improvements in BP, lipid profile observed
  • Phase 3 Trials: TRIUMPH program studying OSA, knee OA
  • Long-term Data: Duration studies ongoing for safety/efficacy
Dose Escalation Strategies
  • 2 mg Start: Better GI tolerance, recommended for most patients
  • 4 mg Start: Faster escalation, higher initial GI side effects
  • Individualized Dosing: Based on tolerance and response
  • Dose Reductions: May be needed for BMI <22 or intolerance
  • Maintenance Strategy: Lowest effective dose for weight maintenance

Medical Disclaimer: Retatrutide is investigational and not FDA-approved. This calculator is based on published Phase 2 clinical trial data for educational purposes only. It does not constitute medical advice. Healthcare providers should consult current medical literature, regulatory guidelines, and clinical protocols before considering any treatment. Individual patient factors, contraindications, and local regulations must be considered. Always follow applicable medical standards and regulatory requirements.

Key formulas used by the calculator
BMI: \[ \mathrm{BMI} = \frac{W}{\left(\frac{H}{100}\right)^2} \]
Expected weight loss at time \(t\): \[ \Delta W_t = W_0 \times \frac{\%\ \text{loss at } t}{100} \] Projected weight at time \(t\): \[ W_t = W_0 - \Delta W_t \]
Escalation interval adjusted for GI tolerance: \[ I_{\text{adj}} = I_{\text{protocol}} \times M_{\text{tolerance}}\quad \text{where } M_{\text{tolerance}} \in \{1.0,\ 1.2,\ 1.5\} \] Steps typically progress through 2 → 4 → 8 → 12 mg once weekly as tolerated.

What the Retatrutide Dosage Calculator Does

The Retatrutide Dosage Calculator builds an evidence-based weekly dosing schedule for an investigational triple-agonist (GIP/GLP-1/glucagon). It estimates when a patient may reach a selected maintenance dose, what weight change the clinical trials reported at 24 and 48 weeks, and which safety checks to plan along the way.

The tool is for education and planning. It does not give medical advice or replace clinical judgment.

What the Calculator Uses

  • Weight & height to compute BMI and confirm the indication window.
  • Primary indication (e.g., obesity, overweight + comorbidity, Diabetes + obesity).
  • Target maintenance dose (4, 8, or 12 mg once weekly).
  • Starting dose and escalation speed (standard, conservative, or rapid intervals).
  • GI tolerance history to slow or maintain the pace of escalation.
  • Comorbidities to show extra monitoring reminders (e.g., diabetes, cardiovascular, liver disease).
  • Clinical checkboxes for heart-rate monitoring, lifestyle support, and safety follow-up.

How to Use the Calculator

  1. Enter weight (kg) and height (cm).
  2. Select the indication.
  3. Choose a target maintenance dose (4, 8, or 12 mg weekly).
  4. Pick a starting dose (2 mg is common) and an escalation speed.
  5. Set GI tolerance and any comorbidities.
  6. Leave helpful options on (e.g., Monitor heart rate, Lifestyle intervention), or adjust as needed.
  7. Click Generate Dosing Schedule.

Tip: Use kilogram and centimeter units. If an entry falls outside the valid range, the tool will prompt you to correct it.

What You Will See

  • Target Maintenance Dose card: the weekly dose and the week it is reached.
  • BMI, expected % loss, and projected target weight based on published trial results.
  • Weekly dosing schedule: initiation, escalation steps, and maintenance milestones (24, 36, 48 weeks).
  • Safety monitoring plan: baseline labs, early follow-ups, and comorbidity-specific items.
  • Clinical guidance: reminders on dose pacing, side-effect support, and expectation setting.

How This Tool Helps

  • Clarifies the plan: shows when dose changes happen and when maintenance is likely.
  • Sets expectations: displays trial-based 24-week and 48-week weight-change benchmarks.
  • Improves counseling: turns GI-tolerance input into a practical timeline you can discuss.
  • Supports safety: lists check-ins for vitals, labs, and heart rate during escalation.
  • Streamlines follow-up: creates a week-by-week schedule that teams can reference in clinic.

Quick Example

A patient at 80 kg and 170 cm with obesity selects an 8 mg target, a 2 mg start, and standard 4-week intervals. With good GI tolerance, the plan steps through 2 → 4 → 8 mg. The maintenance dose is typically shown around the early maintenance window, and the results panel displays the trial-reported percent weight change at 24 and 48 weeks, plus a safety checklist.

Reading the Calculations (Plain Language)

  • BMI uses your weight and height to check eligibility ranges.
  • Expected outcomes apply published percentages to the starting weight to estimate kilograms lost and projected weight.
  • Escalation timing multiplies the protocol interval by a tolerance factor to slow down if prior GI issues exist.

Safety and Limits

  • Retatrutide is investigational and not FDA-approved. This tool is educational.
  • Data source: published Phase 2 trial protocols and efficacy summaries; individual results vary.
  • Use clinical judgment: adjust for patient factors, drug interactions, local guidance, and access pathways.
  • Emergency care beats any schedule: new or severe symptoms require prompt evaluation.

FAQ

Is this medical advice?

No. The calculator supports learning and planning. Always confirm with current guidelines and prescriber direction.

Is retatrutide approved?

No. It is in late-stage research. The tool summarizes trial-based dosing patterns and monitoring reminders.

How are the expected weight changes calculated?

The tool applies published percentage changes to the entered starting weight using the formulas shown above.

What if a patient has GI sensitivity?

Select “Moderate” or “Poor” GI tolerance. The schedule widens the interval before each step-up to reduce side-effect risk.

Does it handle comorbidities?

Yes. Choose diabetes, cardiovascular, liver, or multiple comorbidities to display extra monitoring items (e.g., HbA1c checks, lipid profile, liver function tests).

Who should use this tool?

Clinicians, researchers, and trainees. Patients can review the schedule with their care team, but should not self-dose.

Can I use it for Other medications?

No. Parameters and intervals reflect retatrutide clinical trials. For other therapies, use a medication-specific Dose Calculator or official protocol.

Related Calculators People Also Use

Many teams pair this tool with other clinical calculators to round out assessment and follow-up:

  • Body Surface Area Calculator: review the body surface area formula when dosing other agents (calculate body surface area, BSA value calculation).
  • GFR Calculator / eGFR: check GFR estimation and glomerular filtration rate for renal function (eGFR calculation).
  • Blood Pressure Calculator: track vitals over time (blood pressure analysis, healthy blood pressure range).
  • Corrected Calcium Calculator: confirm corrected calcium levels when albumin varies (calcium correction formula).
  • Child-Pugh Calculator / FIB-4 score tool: review liver disease assessment and fibrosis risk in metabolic liver disease.
  • BUN/Creatinine Ratio Calculator: scan kidney function trends (BUN to creatinine ratio).
  • Maintenance Fluid Calculator: estimate maintenance fluid requirements during illness.
  • BAC (Blood Alcohol Concentration) Calculator: use BAC estimation or an alcohol consumption tracker during lifestyle counseling if relevant.

Best-Practice Tips

  • Confirm units before entering values.
  • Document the schedule in the chart and revisit at each check-in.
  • Combine with coaching on diet, activity, and sleep for better outcomes.
  • If side effects occur, pause escalation or step back, then reassess.

Important Notice

This calculator is for educational purposes only. Retatrutide is investigational. Always follow your local regulations, current literature, and prescriber instructions.