FormBlends Calculators · FormBlends network
Do your GLP-1 dosing arithmetic with the formula shown, so you can check it yourself.
Seven calculators for medication you already have a prescription for: units, schedules, projections, cost per mg, BMI and protein. Nothing is pre-filled.
- 7
- calculators, each with its formula in full
- Every calculator prints its formula and a dated note on what it assumes.
- 100 units = 1 mL
- on a U-100 syringe; units measure volume, not drug
- Syringe units measure volume, not drug. The concentration on your vial decides the dose.
- 4.333
- weeks in a month; using 4 understates annual cost by about 7.7%
- Weeks in an average month. Using 4 understates a year's cost by about 8%.
Start here
Three ways in, depending on what you need right now
Interactive
Calculators
Each runs in your browser, shows its formula, and prints a dated assumptions note. Nothing you type leaves the page.
CalculatorDose unit converter
mg, mcg, mL and syringe units at any vial concentration.
CalculatorInjection schedule generator
Titration dates from your start day, with a calendar file.
Weight-loss projection from trial averages
STEP 1 and SURMOUNT-1 arm averages applied to your weight.
CalculatorCost per month and per mg
Compare up to four options on a per-mg and per-month basis.
CalculatorBMI and context
BMI, WHO category, and the weights at each cut point for your height.
CalculatorProtein target
Daily and per-meal protein from body weight and a sourced range.
Reading
Guides
Each page opens with a plain-English summary, a figure drawn from the data, the numbers that matter, and what it means if you're considering treatment.
Guides
How to use the dose unit converter
You'll get: The converter turns the dose on your prescription and the strength on your vial into millilitres and syringe units.
A walkthrough of the converter: what to type, what each result means, and the two checks that catch almost every drawing-up error before it happens.
Guides
Units versus mL: the mistake that changes a dose tenfold
You'll get: Syringe units measure volume, not drug. On a U-100 syringe, 100 units equals 1 millilitre.
Why syringe units are a volume scale, how one word means three different things, and the arithmetic that keeps a 0.25 mL dose from becoming 2.5 mL.
Guides
How to use the injection schedule generator
You'll get: You enter a start date and dose steps. The tool dates every shot and exports a calendar file.
Turn a start date and your prescribed dose steps into dated injections and a calendar file, with the label rules the templates follow.
Guides
What a population average means: reading the weight-loss projection
You'll get: The projection scales a published trial endpoint to your starting weight and uses a formula for intermediate weeks.
Where the STEP 1 and SURMOUNT-1 numbers come from, what the curve between week 0 and the endpoint is and is not, and the three reasons your own result will differ from the line.
Live updates
What changed since this site was written
Sources checked October 23, 2026, refreshed every six hours.
Newest on PubMed
Papers indexed in the last year matching dosing and pharmacokinetics (51 in total).
- Clinical Feasibility of a Low-Dose Tirzepatide Strategy in Older Adults with Type 2 Diabetes: Persistence, Metabolic Benefit, and Treatment Simplification in a Real-World Cohort
Endocr Pract · October 15, 2026 · PubMed 42880590
- Tirzepatide persistence, adherence, and dose escalation in a real-world setting with high out-of-pocket costs: a Polish cohort study
Adv Med Sci · October 9, 2026 · PubMed 42854961
- Real-world effectiveness and safety of low-dose tirzepatide in Japanese people with type 2 diabetes: a multicenter, retrospective, single-arm, observational study-East Shizuoka Tirzepatide (ESTATE) study
Endocr J · September 29, 2026 · PubMed 42816319
- When dose follows response: Interpreting lower-dose semaglutide effectiveness in clinical practice
Diabet Med · September 16, 2026 · PubMed 42748286
- Tirzepatide and oral progestogens: A hypothesis-generating review of a biologically plausible pharmacokinetic interaction in gynaecologic disease control and menopausal hormone therapy
Maturitas · September 10, 2026 · PubMed 42721915
FDA and enforcement tracker
FormBlends research feed, data as of September 4, 2026.
September 1, 2026 · Adverse-event report update
FDA GLP-1 concerns page updated: 990 adverse-event reports for compounded semaglutide and >730 for compounded tirzepatide (as of May 31, 2026); border screening and fake-pharmacy labelsAugust 28, 2026 · Label or price event
FDA approves Mounjaro (tirzepatide) to reduce MACE risk in adults with type 2 diabetes (SURPASS-CVOT)August 27, 2026 · Court decision
Fifth Circuit affirms summary judgment for FDA in both GLP-1 shortage cases (Nos. 25-10600 tirzepatide; 25-10758 semaglutide)August 24, 2026 · FDA warning letter
FDA warning letters to five peptide vendors: Peak Performance Peptides (735127), Royal Peptides (734884), NuScience Peptides (733652), Peptide Partners (735063), TXP Innovations dba Tex Peptides (735067)August 24, 2026 · FDA warning letter
FDA warning letter: TXP Innovations LLC dba Tex Peptides (Unapproved New Drugs/Misbranded)
Compounded price index
Median all-in cash price per 28 days across providers, as of September 3, 2026.
- semaglutide, month 1 at 0.25 mg/week
- $197
- median of 14 providers
- semaglutide, month 4 at 1 mg/week
- $199
- median of 13 providers
- tirzepatide, month 1 at 2.5 mg/week
- $268
- median of 14 providers
- tirzepatide, month 4 at 5 mg/week
- $299
- median of 12 providers
- September 3, 2026: Index, All, baseline 51 rows. First weekly snapshot. Changes against this baseline will be listed here with the date they were observed.
PubMed lists come from NCBI E-utilities and are not reviewed by us before they appear. Feeds are FormBlends Research data (CC BY 4.0); FormBlends sells compounded GLP-1 drugs and appears in the price index under the same rules as every other provider. Compounded drugs are not FDA approved.
How these calculators are built
Each tool is a small, pure function you can read in the formula panel underneath it. Inputs stay in your browser. Where a tool uses a published number (a trial endpoint, a label titration step, a dietary reference intake) the number is cited inline with a PubMed id, an FDA label or the originating body, and the assumptions note carries the date we last checked it.
What these calculators are not
They are arithmetic aids for medication a licensed prescriber has already prescribed. They do not pre-fill doses, they do not recommend a dose, and they are not built for research chemicals. Compounded GLP-1s are not FDA approved and are not interchangeable with brand products. If a result surprises you, stop and ask your prescriber or pharmacist before you draw anything up.