Your prescription involves three different measurements, and it helps to know how they relate to each other.
Dose is the amount of medication or active ingredient you're meant to receive, usually measured in milligrams (mg).
Concentration is how much medication is packed into each milliliter of liquid in your vial, written as mg/mL.
Units are the numbered lines on your syringe. They measure the volume of liquid you're drawing up, not the strength of the medication itself.
NOTE: Because concentration can differ between vials, the same dose can correspond to a different number of units depending on how your medication was prepared.
Always draw up to the unit number listed on your prescription label or the instructions your clinician gave you. If those numbers don't match what you're seeing on your vial or syringe, don't guess: contact your clinician through the portal before injecting.