Tirzepatide and semaglutide dosage calculator: mg to units

Worked examples

Tirzepatide 2.5mg from a 10 mg/mL vial. 2.5 ÷ 10 = 0.25 mL. 0.25 × 100 = 25 units. You draw to the 25 mark.

Tirzepatide 5mg from a 20 mg/mL vial. 5 ÷ 20 = 0.25 mL. 0.25 × 100 = 25 units. Note that this is the same 25 units as the first example, for twice the dose, because the vial is twice as strong. That is exactly why "how many units is 5mg" has no single answer.

Semaglutide 0.5mg from a 2.5 mg/mL vial. 0.5 ÷ 2.5 = 0.2 mL. 0.2 × 100 = 20 units.

Twenty units is always 0.2 mL. What that 0.2 mL contains is the part that changes. Check your label every time you start a new vial, because a refill can arrive at a different concentration than the one before it.

Tirzepatide

Tirzepatide is given once weekly. It starts at 2.5mg, which is a tolerance-building dose rather than a treatment dose, and increases in 2.5mg steps no sooner than every four weeks. The maximum approved dose is 15mg once weekly.

Four weeks is a minimum interval, not a deadline. Holding at a dose longer, or stepping back down, are both ordinary clinical decisions and neither means starting over. Many people stay at 5mg or 10mg indefinitely because it is working and they tolerate it. Anything above 100 units will not fit in a standard 1 mL syringe, which is usually a sign that the concentration needs checking rather than that you need two syringes.

Semaglutide

Semaglutide is also once weekly, starting at 0.25mg with increases no sooner than every four weeks. The maximum approved dose for chronic weight management is 2.4mg once weekly. Note that this is a completely different ladder from tirzepatide: 2.5mg to 15mg is the tirzepatide range and does not apply to semaglutide.

Ozempic®, which is semaglutide approved for type 2 diabetes rather than weight management, uses a different ladder and tops out at 2mg once weekly. Wegovy®, semaglutide approved for chronic weight management, follows the schedule above and is titrated up to 2.4mg, with a higher-dose version running to 7.2mg.

Limits

It does not reconstitute anything. If you have been dispensed a powder that has to be mixed with bacteriostatic water before use, the concentration you enter here is the concentration after mixing, which your pharmacy states on the label. Choosing a diluent, choosing a volume and setting a beyond-use date are pharmacy decisions, not patient decisions. Do not calculate your own reconstitution volume from a forum post.

It does not check whether your dose is right for you. It converts a dose you were already prescribed. Whether that dose should go up, stay where it is, or come down is a clinical judgement made by the provider who knows your history.

It does not apply to pens. Zepbound®, Mounjaro®, Wegovy® and Ozempic® pens deliver a fixed dose. There is nothing to measure and no unit conversion to do. If you use a pen, the only number that matters is the one on the dose display or the label.

Reading a U-100 syringe. Most 1 mL U-100 syringes are marked in 2 unit increments, so a 25 unit draw sits on a line. Some 0.3 mL and 0.5 mL syringes are marked in 1 unit or half-unit increments. If your calculated dose lands between marks, that is a question for your pharmacy about which syringe you should have been dispensed, not something to estimate by eye. Hold the syringe at eye level, read from the flat top edge of the plunger stopper rather than the rounded tip, and expel air bubbles before you read the final number, because a bubble takes up volume.

Three situations are worth a phone call rather than a judgement call. The calculator gives a unit number different from your pharmacy label. Your refill arrived at a different concentration from your last vial. Your calculated volume is more than a 1 mL syringe holds. None of these are emergencies. They mean one number needs confirming before you inject. Society support typically replies within 24 hours at support@societyofyou.com or (888) 584-5602.

Questions

This calculator performs arithmetic only. It does not provide medical advice and does not replace the instructions from your prescriber or the labeling supplied with your medication. If you want a licensed US practitioner to review your history and set a dose in the first place, the free 2-minute evaluation is where that starts. Semaglutide from $149 per month, tirzepatide from $249 per month, delivered in 1 to 2 days, free and discreet, no insurance required.

* Individual results may vary, and not all patients will qualify for treatment. Always consult a licensed healthcare provider before starting or modifying any medical treatment.

Society facilitates access to consultations with independent, licensed healthcare providers who evaluate each patient and determine eligibility for treatment. Prescription products require an online medical evaluation. Medications are prescribed by independent physicians and dispensed by licensed U.S. pharmacies or a patient's preferred pharmacy. Only a qualified healthcare provider can determine whether a treatment is appropriate for an individual's specific medical needs.
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‍Society partners with licensed U.S. pharmacies. Certain treatments may include compounded medications, which are not FDA-approved and have not been evaluated by the Food and Drug Administration for safety, efficacy, or quality. Compounded medications may be prescribed by a healthcare provider based on individual patient needs or during periods of drug shortages. FDA-approved GLP-1 medications—such as Ozempic® (semaglutide), Wegovy® (semaglutide), and Zepbound® (tirzepatide)—are not compounded. Society is not affiliated with, endorsed by, or sponsored by the manufacturers of these products. All trademarks and brand names belong to their respective owners.
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