mg, mL & Units on Compounded Semaglutide Labels
These terms describe different measurements. This page explains the terminology generally; it does not provide dosing or injection instructions.
General education only
This article does not provide dosing or injection instructions. Follow the directions provided for your current prescription by your prescribing clinician and dispensing pharmacy.
What the terms mean
mg (milligrams) describes an amount of medication.
mL (milliliters) describes a volume of liquid.
mg/mL describes concentration—the amount of medication in each milliliter of liquid.
Syringe units are markings used to measure volume on some syringes. They are not milligrams.
A simple way to think about concentration
Imagine two cups containing the same amount of liquid. One has more drink mix than the other, so it is more concentrated.
Medication concentration follows the same general idea: the same liquid volume can contain different amounts of medication.
Why the terms are not interchangeable
Some compounded injectable semaglutide products are available in different concentrations. When concentration differs, the same liquid volume or syringe marking cannot be assumed to contain the same amount of medication.
Only your licensed prescribing clinician or dispensing pharmacy can confirm how the directions apply to your specific prescription, medication container, and syringe.
Why the FDA has raised this issue
The FDA has received reports of dosing errors involving compounded injectable semaglutide. The agency has identified confusion among milligrams, milliliters, syringe units, and varying concentrations as factors that may contribute to these errors.
The FDA encourages patients to talk with their healthcare provider or compounder about how to measure and administer an intended dose.
Read the FDA dosing-error alert and its information about unapproved GLP-1 drugs.
If something is unclear
Do not use this page, another person's directions, or instructions from an earlier prescription to calculate or convert a dose. Contact your licensed prescribing clinician or dispensing pharmacy before using the medication if your current label or written instructions are unclear.
Sources and further reading
This article is for general educational purposes only. It is not medical advice or a dosing guide. For questions about your prescription, contact your prescribing clinician or dispensing pharmacy. Compounded medications are not FDA-approved or reviewed by the FDA for safety, effectiveness, or quality.