Free tools

GLP-1 calculators & simulators

Evidence-based, FDA-label-cited interactive tools for patients on or considering weight-loss medications. Every calculation is educational and the underlying clinical sources are documented on each tool page.

Decision support
GLP-1 Drug Decision Quiz
Multi-step decision engine that maps BMI, comorbidities, form preference, and special populations to the FDA-approved GLP-1 medication match — Wegovy, Zepbound, Mounjaro, Ozempic, Saxenda, Foundayo, or Rybelsus — with cited trial evidence (STEP, SURMOUNT, SELECT, FLOW, STEP-HFpEF, SURMOUNT-OSA, STEP-TEENS) at every branch.
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Weight loss predictor
GLP-1 Weight Loss Calculator
STEP-1, SURMOUNT-1, and ATTAIN-1 trial-data-backed predictor. Enter your starting weight and target week to see week-by-week predicted weight loss across all three drugs.
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BMI + eligibility
GLP-1 BMI Calculator
BMI calculator with a GLP-1 outcome overlay. See your current WHO BMI category, your Wegovy/Zepbound FDA eligibility, and what category you'd land in at each trial endpoint.
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Calorie + deficit
Calorie Deficit Calculator
Enter your sex, age, height, weight, and activity level to get your BMR, maintenance calories (TDEE), and the daily calorie target for losing 0.5–2 lb per week — Mifflin-St Jeor, with a built-in safety floor and the GLP-1 appetite-deficit context.
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Cost comparison
GLP-1 Savings Calculator
Compare 10 different access paths — brand-name, manufacturer direct-pay, compounded vials, and Foundayo at $149/month — and see your monthly, yearly, and 5-year savings or extra cost. Updated with current pricing.
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Dosage calculator
GLP-1 Unit ↔ mg Converter
Convert prescribed milligrams of compounded semaglutide or tirzepatide to insulin syringe units (and back) at any vial concentration. Now includes a reconstitution (BAC water) calculator for lyophilized vials. FDA prescribing information cited.
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Pharmacokinetics
GLP-1 Dose & Concentration Plotter
Visualize how semaglutide, tirzepatide, orforglipron, and retatrutide build up in the body across the standard titration schedule. Sourced from FDA prescribing information and the published pharmacokinetic literature.
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Pharmacokinetics
GLP-1 Washout Calculator
How long does semaglutide / tirzepatide / orforglipron stay in your system after your last dose? See exactly when you reach 50%, 25%, 5%, 1% remaining — built on FDA-label half-lives. Includes clinical scenarios for switching, surgery hold, pregnancy planning, and trial enrollment.
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Drug interactions
GLP-1 Drug Interaction Checker
Search any medication to see how it interacts with Wegovy, Ozempic, Zepbound, Mounjaro, or Foundayo. Severity-tiered results — contraindicated, serious, moderate, minor — with FDA prescribing-information citations and what-to-do guidance.
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Side effects
GLP-1 Side Effect Timeline
When does each GLP-1 side effect peak and resolve? Interactive 6-drug × 7-side-effect × 5-week-bucket matrix. Every cell anchored to an FDA label (DailyMed) or a pivotal-trial publication, with verbatim primary-source quote on click.
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Pen tracker
GLP-1 Pen Leftover Calculator
How many doses are left in your Ozempic or Saxenda pen? Built on FDA-label fill volumes and dose counts. Explains why Wegovy, Zepbound, and Mounjaro pens are single-dose and cannot be extended.
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Insurance coverage
Insurance Employer Checker
Look up Wegovy, Zepbound, Ozempic, and Mounjaro coverage at 30 large US employers including Amazon, Walmart, Google, Microsoft, and the federal government. Patient-reported and publicly-sourced — verify with your HR before assuming coverage.
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Pre-op planning
GLP-1 Pre-Op Stop-Date Calendar
Surgery date in, last-safe-dose date out. ASA 2023 + 2024 multisociety guidance translated into specific calendar dates for Wegovy, Ozempic, Zepbound, Mounjaro, Saxenda, Rybelsus, Foundayo, and compounded GLP-1s. Includes 'I forgot to stop' recovery branch and a print-friendly summary for your anesthesia team.
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Injection technique
GLP-1 Injection-Site Rotation Calendar
Log your last few injections by site; the tracker picks the next FDA-label-compliant site (abdomen / thigh / upper arm) and shows a body diagram. Prevents lipohypertrophy and stacked site reactions. Printable rotation card for the fridge.
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Insurance coverage
Skin-Removal Cost & Insurance Qualifier
Will insurance cover your panniculectomy, brachioplasty, or thighplasty? Maps your profile (peak BMI, current BMI, months stable, documented complications, insurer) to the medical-necessity criteria in Aetna CPB 0211, Cigna 0192, UnitedHealthcare CDG 2023T0570U, and Anthem CG-SURG-58. ASPS cash-pay ranges when coverage is unlikely.
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Editorial guides

Tools answer “how much” and “when”; the editorial guides answer “which drug,” “at what cost,” and “will my insurance cover it.”

Weight loss injections guide →

Every FDA-approved injectable option (Wegovy, Zepbound, Saxenda) plus off-label T2D injectables, the investigational pipeline, and cross-trial caveats.

Live GLP-1 pricing index →

Brand list prices, NovoCare / LillyDirect / Costco self-pay, and compounded cash-pay across every channel we track. Refreshed monthly.

Full GLP-1 medication list →

Reference table of every FDA-approved GLP-1 with brand, manufacturer, indication, dose ladder, route, and primary-source DailyMed SetID links.

Insurance coverage by program →

Medicare Part D rules, the 6-state Medicaid taxonomy (TX / CA / NY / FL / OH / IL), commercial PBM dynamics, and FEHB. Primary-source verified.

These tools are educational and do not provide medical advice, diagnosis, or treatment recommendations. Dosing decisions should always be made with a qualified healthcare provider.