Concentration and dosage are two important concepts when it comes to medication.

Concentration: This refers to how much of the active ingredient is present in a given volume of the medication. It's like looking at how much coffee is in your cup. For example, if you have a cup of coffee with a high concentration of caffeine, it means there's a lot of caffeine packed into that small cup. Similarly, in medication, concentration tells us how strong or potent the medicine is per unit of volume. It's usually measured in milligrams (mg) per milliliter (ml) or another appropriate unit.

Dosage: Dosage, on the other hand, is the amount of medication you should take at one time, or over a certain period, as prescribed by your doctor or indicated on the medication label. It's like how many cups of coffee you drink in a day. For instance, if your doctor prescribes you to take 200 mg of a medication, that's your dosage. It doesn't tell you how concentrated the medication is; it just specifies the amount you should take. In summary, concentration tells you how strong the medication is in a given volume, while dosage tells you how much of the medication you should take based on your prescription or instructions.

This patient was prescribed Tirzepatide 5mg/week. The concentration is 5mg/0.5mL, meaning there’s 5mg in every 0.5mL solution. There’s a total of 2mL solution in the entire vial: 5mg/0.5mL x 2mL = 20mg Tirzepatide in the entire vial, enough for the whole month (5mg/week x 4 weeks = 20mg Tirzepatide).

Alternative scenario based on image above:

If the patient was prescribed Tirzepatide 2.5mg/week and if the vial had the same concentration, the total amount of solution would be 1mL (half the amount of solution in the image above): 5mg/0.5mL x 1mL = 10mg Tirzepatide in the entire vial (2.5mg/week x 4 weeks = 10mg Tirzepatide)

This patient was prescribed Tirzepatide 7.5mg/week. The concentration is 10mg/mL, meaning there’s 10mg in every 1mL solution. There’s a total of 3mL solution in the entire vial: 7.5mg/mL x 3mL = 30mg Tirzepatide in the entire vial, enough for the whole month (7.5mg/week x 4 weeks = 30mg Tirzepatide). Note: if you don’t see the total amount of solution on the front of the label, be sure to look at the side of the label on the vial to see the total amount of solution as in this case

This patient was prescribed Semaglutide 0.25mg/week. The concentration is 1mg/mL, meaning there’s 1mg in every 1mL solution. There’s a total of 1mL solution in the entire vial: 1mg/mL x 1mL = 1mg Semaglutide in the entire vial, enough for the whole month (0.25mg/week x 4 weeks = 1mg Semaglutide). This label looks a bit different because it’s compounded with vitamin B12 so the label looks a tad different: 1mg/0.5mg/mL. It means there’s 1mg Semaglutide and 0.5mg B12 in every 1mL solution.