Calculators
Calculators for dose, cost and timing
15 tools for the arithmetic that sits either side of a GLP-1 purchase: how much drug is actually in the vial, when it clears, and what a year on each access path adds up to. Every input and source is listed on the tool page itself.
Milligrams are not units
Compounded semaglutide and tirzepatide are sold by vial concentration, so one prescribed dose is a different number of syringe units at 2.5 mg/mL than at 10 mg/mL. The converter and the reconstitution calculator exist because that is the step people get wrong.
A month is not a year
The advertised GLP-1 figure is often a first month, a prepay term or a membership fee. The savings calculator runs each path out to a year and to five, and it will report a higher total as readily as a lower one.
Every number has a source
Half-lives, titration schedules, fill volumes and side-effect windows come from FDA prescribing information on DailyMed or from the pivotal trial publications. Each page names what it used, so the math can be checked against the label rather than against us.
Decision support
GLP-1 Drug Decision Quiz
Answer for BMI, comorbidities, form preference and special populations, and each branch names the FDA-approved match: Rybelsus, Saxenda, Ozempic, Mounjaro, Zepbound, Foundayo or Wegovy. The trial behind every branch is cited, from STEP-TEENS and SURMOUNT-OSA through STEP-HFpEF, FLOW, SELECT, SURMOUNT and STEP.
→Weight loss predictor
GLP-1 Weight Loss Calculator
Enter a starting weight and a target week to see predicted week-by-week loss on all three drugs. The curves are built from ATTAIN-1, SURMOUNT-1 and STEP-1 trial data rather than from any seller's own figures.
→BMI + eligibility
GLP-1 BMI Calculator
Your current WHO BMI category, whether you meet the FDA eligibility thresholds for Wegovy or Zepbound, and the category you would land in at each trial endpoint. Eligibility is a label question before it is a seller question.
→Calorie + deficit
Calorie Deficit Calculator
Sex, age, height, weight and activity level in; BMR, maintenance calories (TDEE) and the daily target for losing 0.5-2 lb a week out. It runs on Mifflin-St Jeor, holds a safety floor, and sets the GLP-1 appetite deficit in context.
→Cost comparison
GLP-1 Savings Calculator
Ten access paths set side by side: compounded vials, manufacturer direct-pay, brand-name, and Foundayo at $149/month. It returns the monthly, yearly and 5-year difference, which lands as an extra cost as often as a saving. Updated with current pricing.
→Dosage calculator
GLP-1 Unit ↔ mg Converter
Prescribed milligrams of compounded semaglutide or tirzepatide into insulin syringe units, and back again, at any vial concentration. A BAC water reconstitution calculator for lyophilized vials is built in. Cited to FDA prescribing information.
→Pharmacokinetics
GLP-1 Dose & Concentration Plotter
How semaglutide, tirzepatide, orforglipron and retatrutide accumulate in the body over the standard titration schedule, drawn as a curve. Built from the published pharmacokinetic literature and from FDA prescribing information.
→Pharmacokinetics
GLP-1 Washout Calculator
The time from a last dose of semaglutide, tirzepatide or orforglipron to 50%, 25%, 5% and 1% remaining, worked from FDA-label half-lives. Clinical scenarios cover switching drugs, holding for surgery, pregnancy planning and trial enrollment.
→Drug interactions
GLP-1 Drug Interaction Checker
Search a medication and see how it interacts with Foundayo, Mounjaro, Ozempic, Wegovy or Zepbound. Results are tiered contraindicated, serious, moderate and minor, each carrying an FDA prescribing-information citation and what to do about it.
→Side effects
GLP-1 Side Effect Timeline
A 6-drug by 7-side-effect by 5-week-bucket matrix showing when each effect peaks and when it settles. Every cell is anchored to an FDA label on DailyMed or to a pivotal-trial publication, and a click shows that primary source verbatim.
→Pen tracker
GLP-1 Pen Leftover Calculator
Doses remaining in an Ozempic or Saxenda pen, worked out from FDA-label fill volumes and dose counts. It also sets out why the Mounjaro, Zepbound and Wegovy pens hold a single dose that cannot be stretched further.
→Insurance coverage
Insurance Employer Checker
Coverage for Mounjaro, Ozempic, Zepbound and Wegovy at 30 large US employers, among them Walmart, Microsoft, Amazon, Google and the federal government. The entries are patient-reported and publicly sourced, so confirm with your own HR before you assume anything.
→Pre-op planning
GLP-1 Pre-Op Stop-Date Calendar
Give it a surgery date and it returns the last safe dose date. The ASA 2023 and 2024 multisociety guidance is turned into calendar dates for Saxenda, Rybelsus, Ozempic, Mounjaro, Wegovy, Zepbound, Foundayo and for compounded GLP-1s. There is a branch for having already missed the stop date, and a summary you can print for the anesthesia team.
→Injection technique
GLP-1 Injection-Site Rotation Calendar
Record where your last few injections went and the tracker returns the next site that is compliant with the FDA label, abdomen, thigh or upper arm, on a body diagram. The point of rotating is to avoid lipohypertrophy and stacked site reactions. A printable card is included for the fridge.
→Insurance coverage
Skin-Removal Cost & Insurance Qualifier
Whether an insurer is likely to pay for a panniculectomy, brachioplasty or thighplasty. Your insurer, current BMI, peak BMI, months stable and documented complications are matched against the medical-necessity criteria set out in Anthem CG-SURG-58, UnitedHealthcare CDG 2023T0570U, Cigna 0192 and Aetna CPB 0211. Where coverage looks unlikely it falls back to ASPS cash-pay ranges.
→
Longer reference pages
The calculators handle the arithmetic. These pages handle the parts that have to be read: which drug the label actually covers, what each channel is charging this month, and what an insurer will and will not pay for.
Nothing here is medical advice, a diagnosis, or a treatment recommendation. These pages are arithmetic and citations. Any change to a dose belongs with a licensed clinician who knows your history.
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Gala
Moving between compounded and brand without changing seller
From $129/mo
Get started →Synergy Rx
Knowing which pharmacy fills the vial — it names Belmar Pharmacy
From $199/mo
Get started →Strut Health
Semaglutide at $99/month, 48% under the register median
From $99/mo
Get started →