How many units is 2.5 mg of tirzepatide?

It depends entirely on the vial concentration. On a 10 mg/mL vial, 2.5 mg is 0.25 mL = 25 units on a U-100 insulin syringe. On 15 mg/mL it is about 17 units; on 17 mg/mL about 15 units; on 20 mg/mL 12.5 units; on 30 mg/mL about 8 units. Always divide the dose in mg by the concentration in mg/mL, then multiply by 100 to get units.

What is the tirzepatide dosing schedule for weight loss?

The Zepbound label schedule: 2.5 mg once weekly for 4 weeks, then 5 mg. After at least 4 weeks at each step, increase by 2.5 mg to 7.5, 10, 12.5 and up to 15 mg as needed and tolerated. Maintenance doses are 5, 10 or 15 mg. Compounded tirzepatide follows the same milligram schedule.

How do I convert tirzepatide mg to units?

Units = (dose in mg ÷ vial concentration in mg/mL) × 100. Example: 7.5 mg from a 15 mg/mL vial = 0.5 mL = 50 units. Example: 10 mg from a 20 mg/mL vial = 0.5 mL = 50 units. Use the concentration printed on your vial label and Certificate of Analysis, never a chart from another pharmacy.

What syringe should I use for compounded tirzepatide?

A U-100 insulin syringe. For doses under 30 units a 0.3 mL (30-unit) syringe with half-unit marks is most accurate; for 30-50 units a 0.5 mL syringe; for larger volumes a 1 mL (100-unit) syringe. Needle length 4-6 mm (29-31 gauge) for subcutaneous injection into abdomen or thigh.

Why is my tirzepatide dose in units different from someone else's?

Because compounding pharmacies supply different concentrations — 10, 15, 17, 20 and 30 mg/mL are all common — and some vials come as powder you reconstitute yourself, which sets the concentration based on how much water you add. The same 5 mg dose is 50 units at 10 mg/mL and 25 units at 20 mg/mL. Comparing units between people is meaningless; compare milligrams.

What are the most common tirzepatide dosing mistakes?

Two account for most emergency calls: reading a chart for the wrong concentration (drawing 50 units from a 20 mg/mL vial thinking it is 10 mg/mL gives 10 mg instead of 5 mg), and confusing mL with units on the syringe (0.5 mL is 50 units, not 5). A third is restarting at a high dose after a gap of two or more weeks. Verify concentration, verify syringe type, and restart lower after breaks.

Back to blog

Tirzepatide Dosing in Units: mg to Units Chart for Every Common Vial Concentration

The weekly tirzepatide schedule in milligrams, converted to insulin-syringe units for 10, 15, 17, 20 and 30 mg/mL vials — plus the formula, the right syringe, and the two errors that send people to urgent care.

October 8, 2026Healthy-Weight Editorial8 min read

Medically reviewed by Dr. Sarah Chen, MD

Medically reviewed|US-licensed providers|Compounded GLP-1|No insurance needed

Doctor-backedCompounded GLP-1No insurance neededShips in 3-5 days

Lose 15-22% body weight with doctor-backed GLP-1s

Compounded semaglutide & tirzepatide from ~~$350/mo~~ $147/mo. Free online consultation with a US-licensed provider. If approved, medication ships to your door in 3-5 days. No insurance needed.

⚡ Limited spots this month — 50,000+ patients already started

See if I qualify — Free consultation

Available online · Shipped to your door anywhere in the US

Paid partnership · Prescription product requiring a physician consultation · Not everyone qualifies · Results vary

Tirzepatide Dosing in Units: mg to Units Chart for Every Common Vial Concentration

The formula

Units = (dose in mg ÷ vial concentration in mg/mL) × 100. A U-100 insulin syringe has 100 units per millilitre, so units are just millilitres × 100. The only number you need from your pharmacy is the concentration on the vial label — and it must match the Certificate of Analysis. Nothing on this page replaces that label.

Tirzepatide mg → units chart

Weekly dose	10 mg/mL	15 mg/mL	17 mg/mL	20 mg/mL	30 mg/mL
2.5 mg	25 u (0.25 mL)	16.7 u (0.17 mL)	14.7 u (0.15 mL)	12.5 u (0.13 mL)	8.3 u (0.08 mL)
5 mg	50 u (0.50 mL)	33.3 u (0.33 mL)	29.4 u (0.29 mL)	25 u (0.25 mL)	16.7 u (0.17 mL)
7.5 mg	75 u (0.75 mL)	50 u (0.50 mL)	44.1 u (0.44 mL)	37.5 u (0.38 mL)	25 u (0.25 mL)
10 mg	100 u (1.00 mL)	66.7 u (0.67 mL)	58.8 u (0.59 mL)	50 u (0.50 mL)	33.3 u (0.33 mL)
12.5 mg	125 u (1.25 mL)	83.3 u (0.83 mL)	73.5 u (0.74 mL)	62.5 u (0.63 mL)	41.7 u (0.42 mL)
15 mg	150 u (1.50 mL)	100 u (1.00 mL)	88.2 u (0.88 mL)	75 u (0.75 mL)	50 u (0.50 mL)

"u" = units on a U-100 insulin syringe. Round to the nearest half-unit mark your syringe shows. If your vial is a different concentration, apply the formula above. Brand Zepbound and Mounjaro pens are pre-filled at fixed doses and do not use units; LillyDirect Zepbound vials are single-dose (2.5-15 mg per 0.5 mL) and are drawn up whole.

Compounded tirzepatide with a provider who sets your dose and concentration — from $119/month.

Check my eligibility

Available online. Shipped directly to your door.

Weekly titration schedule

Weeks	Dose	Notes
1-4	2.5 mg	Starter; minimal weight effect, tolerability only
5-8	5 mg	First maintenance-eligible dose
9-12	7.5 mg	Optional step; many hold here
13-16	10 mg	Maintenance dose in SURMOUNT (~19-20% loss)
17-20	12.5 mg	Optional step
21+	15 mg	Maximum (~21% loss at 72 weeks)

Hold each step at least 4 weeks; longer is fine. Increases are a prescriber decision. Expected loss by dose is in tirzepatide dosage for weight loss.

Choosing the syringe

Under 30 units: 0.3 mL (30-unit) syringe with half-unit markings — most accurate for 2.5-5 mg on concentrated vials.
30-50 units: 0.5 mL (50-unit) syringe.
Over 50 units: 1 mL (100-unit) syringe; consider asking for a higher concentration to keep volume under 0.5 mL.
Needle: 29-31 G, 4-6 mm (5/16" or 1/4"), subcutaneous in abdomen (2 inches from navel) or front of thigh, rotating sites. See GLP-1 needle size.

Reconstituting powder vials

Some pharmacies ship lyophilised tirzepatide with bacteriostatic water. The concentration is set by how much water you add: 30 mg powder + 3 mL water = 10 mg/mL; + 1.5 mL = 20 mg/mL. Follow the pharmacy's instructions exactly, write the resulting concentration on the vial, and use the matching column above. Step-by-step in the reconstitution guide; storage rules in the storage guide.

The two errors that cause overdoses

Wrong-concentration chart. Drawing 50 units because "5 mg is 50 units" — true at 10 mg/mL, but 10 mg at 20 mg/mL. Doubling a tirzepatide dose produces severe nausea and vomiting for days. Always check your vial.
mL vs units confusion. 0.5 mL is 50 units. Someone told "take 0.5" who draws 5 units gets one-tenth of the dose; someone told "50" who reads it as 0.50 mL on a 1 mL syringe and then draws 50 mL-marks… cannot, but a 3 mL syringe makes the error possible. Use insulin syringes only.

A third, less dramatic error: restarting at the old dose after 2+ weeks off. Drop back a step. If you suspect an overdose, see GLP-1 overdose: what to do.

Switching from semaglutide to tirzepatide

Milligrams do not transfer between the two drugs. Regardless of your semaglutide dose, tirzepatide starts at 2.5 mg one week after the last semaglutide injection. Details and effect-equivalents in switching semaglutide to tirzepatide.

Compare compounded tirzepatide providers by price and pharmacy transparency.

Check my eligibility

Related guides

Compounded GLP-1Results in 4-8 weeks

Lose 15-22% body weight — GLP-1s from $147/month

Compounded semaglutide & tirzepatide prescribed online by US-licensed providers. No insurance needed — medication shipped to your door in 3-5 days.

⚡ Limited spots this month — 50,000+ patients already started

See if I qualify — Free consultation

From $147/month · No insurance needed · Ships nationwide in 3-5 days · Paid partnership · Results vary

Doctor-backed GLP-1 weight loss from $147/month

Compounded semaglutide & tirzepatide. Online consultation with a US-licensed provider. No insurance needed.

⚡ Limited spots this month — 50,000+ patients already started

See if I qualify — Free consultation

Paid partnership · Prescription product · Not everyone qualifies · Results vary

Real patients. Real results.

Join 50,000+ patients who transformed their lives with GLP-1 medications

"I tried everything — keto, intermittent fasting, gym memberships. Nothing worked long-term. GLP-1 changed everything. I lost 47 pounds in 8 months and finally feel like myself again. The online process was so easy — I had my prescription in 2 days."

Jessica M., 38

Texas

-47 lbs

in 8 months

Compounded semaglutide

"At 52, my doctor said I was heading toward diabetes. I started tirzepatide through a telehealth program and lost 62 pounds. My A1C is back to normal, my blood pressure dropped, and I'm off two medications. Wish I'd done this years ago."

David R., 52

Florida

-62 lbs

in 11 months

Tirzepatide (Zepbound)

"I was skeptical about doing this online, but the whole process was professional and easy. My provider answered all my questions, and the medication arrived in 4 days. I've lost 38 pounds and finally have energy to play with my kids again."

Aisha K., 34

California

-38 lbs

in 6 months

Compounded semaglutide

Results vary. These testimonials reflect individual experiences and are not typical. Weight loss depends on diet, activity, and adherence to medication.

How it works — 3 simple steps

Take the 60-second quiz

Answer a few questions about your health, weight goals, and medical history. It's free and confidential.

1 min

Meet your US-licensed provider

A board-certified clinician reviews your profile and prescribes the right GLP-1 medication for you — entirely online.

24-48 hrs

Get medication shipped to your door

Your prescription is filled by a US pharmacy and delivered in discreet packaging in 3-5 business days.

3-5 days

Get GLP-1 savings alerts & weekly tips

Join 50,000+ readers. Price drops, new coupons, and expert weight-loss advice — delivered weekly. Unsubscribe anytime.

Free. No spam. Unsubscribe anytime.

or check my eligibility now