Nasal SprayFrom $166/mo
InjectionFrom $166/mo
Medically reviewed by Vanessa Niles, R.N., M.D., F.A.C.O.G. —
The short answer
Volume to draw (mL) = prescribed dose (mg) ÷ vial strength (mg/mL). On a U-100 insulin-style syringe, units = mL × 100. The right dose for you is the one your provider prescribes; the calculator only does the math.
- Enter your prescribed dose in mg and the strength printed on your vial in mg/mL.
- 1 mL equals 100 units on a U-100 syringe.
- Double-check the result against your pharmacy label and instructions.
- If anything doesn't match, call your pharmacy or provider before injecting.
How to use the calculator
Find your prescribed dose in milligrams on your instructions, and the strength (mg per mL) and size (mL) on your vial label. Type them in and the calculator shows the volume to draw in mL, the matching units on a U-100 syringe and roughly how many doses the vial holds.
Why getting the units right matters
In 2024 the FDA reported dosing errors with compounded injections caused by confusion between milliliters, milligrams and syringe units. Some patients gave themselves 5 to 20 times the intended dose.
The FDA has also noted that compounded labels often show strength per mL more prominently, which can be mistaken for the total amount in the vial.
The formula
Three numbers you need
Your prescribed dose, your vial's strength and your syringe type. With those, drawing the right amount is simple arithmetic.
Worked example
Say your provider prescribes 100 mg and your vial is 200 mg/mL. 100 ÷ 200 = 0.5 mL, which is 50 units on a U-100 syringe. A 5 mL vial at 200 mg/mL, the size NADMedics ships, holds 1,000 mg, or about 10 doses of 100 mg.
These numbers are only an example of the math, not a recommended dose.
NAD+ terms used in this guide
Questions
Questions people also ask
Can this calculator tell me what dose to take?
No. Only your provider can set your dose. The calculator converts the dose you've been prescribed into a volume to draw.
What's a U-100 syringe?
A syringe marked in units where 100 units equals 1 mL. Insulin syringes are the common example.
My answer is over 100 units. What now?
That's more than 1 mL and more than a 1 mL syringe holds. Stop and check your numbers with your pharmacy or provider.
Why does the calculator start with a 5 mL vial?
That's the NADMedics injection: 200 mg/mL in a 5 mL vial. Change the numbers if your label is different.
Can I use this calculator for nasal spray?
No. Nasal spray is measured per spray, not drawn into a syringe. See our NAD+ nasal spray dosage guide instead.
What if the result doesn't match my instructions?
Follow your pharmacy label and call your pharmacy or provider before you inject.
Keep reading
Related NAD+ guides
- How Much NAD+ Should I Inject? Dosage Made Simple for YouHow much NAD+ should you inject? There's no FDA-approved dose, so your provider sets it. Learn what shapes that dose, what studies used and how to measure it.NAD+ injections
- How to Inject NAD+: A Safe Step-by-Step Guide for BeginnersHow to inject NAD+ at home: prepare, draw your dose from the vial, inject under the skin, rotate sites and dispose of needles safely. A beginner's guide.NAD+ injections
- NAD+ Injection Dosage Per Day: How Much Is Truly Safe Daily?Is there a safe daily NAD+ injection dose? No limit has been established. See what studies show about daily NAD+, side effects and why your provider sets it.NAD+ injections
Official sources
Sources and official resources
Official government and research sources behind this page, so you can check the facts yourself.
- U.S. Food and Drug AdministrationFDA alerts about dosing errors with compounded injectable products (2024)
Mix-ups between milliliters, milligrams and syringe units led to overdoses.
- U.S. Food and Drug AdministrationDifferences in strength expression on compounded product labels may lead to dosing errors
Why reading mg per mL correctly matters.
- MedlinePlus (National Library of Medicine)Drawing medicine out of a vial
Step-by-step guide to drawing a dose from a vial into a syringe.
- MedlinePlus (National Library of Medicine)Subcutaneous (SQ) injections
Step-by-step guide to giving a shot into the fatty tissue under the skin.
- U.S. Food and Drug AdministrationSafely Using Sharps (Needles and Syringes) at Home, at Work and on Travel
How to store and throw away used needles and syringes safely.
Medically reviewed by Dr. Vanessa Niles, R.N., M.D., F.A.C.O.G., on October 12, 2026. This article is general education, not medical advice. NAD+ has no FDA-approved use, and compounded NAD+ is not FDA-approved or evaluated by the FDA for safety or effectiveness. Only your provider can set your dose.
Talk it through with a provider
Book a free online consultation. If NAD+ fits, a licensed U.S. provider prescribes the nasal spray or injection, with plans from $166 a month.
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