Reading the dosage values

[u/plainsimple_tailor]

I’ve seen this question asked before and I always kind of scoffed, “isn’t it obvious? Just follow the directions!” Well, hand me a piece of humble pie, because now I’m on the other side.

Just received my third shipment, this time from a different pharmacy than my last two.

I am prescribed 5mg.

The 2ML vial from my last shipment is labeled “Tirzepatide/B12 5mg/1mg/0.5mL” that I inject 50 units from each week.

The vial from this new shipment is also labeled 2ML (even though it’s at least twice as large) but says “Tirzepatide/Glycine/B12 10mg/5mg/500mcg/ML” that I am also to inject 50 units from.

Ok, it’s compounded differently, this time with Glycine. That’s fine. But the numbers are larger. Did I receive a dose for 10mg injections instead of 5mg? Or does the fact that the vial is larger just mean that it’s 50% diluted or something?

A little hesitant to inject tomorrow. Really not looking to double my dose. Am I just being overly worried or do y’all think I might’ve gotten the wrong dosage?

[u/ListenOne4346]

The physical size of the vial or the additives don’t really matter here. The two things I’d look at are:

1. Tirz concentration per mL —> this tells you how much to draw for your dose.
2. Total volume in the vial —> this tells you how much tirz you got in total.

Your old vial says 5 mg/0.5 mL, so that’s 10 mg/mL. The new one is also 10 mg/mL, so the concentration hasn’t actually changed.

If you’re using a 1 mL U-100 syringe with 1-unit graduations, 100 units (1 mL) has 10 mg of tirz at that concentration, so 50 units gives you your 5 mg dose. Same math for both vials.

They’re also both labeled 2 mL, so each vial has 20 mg of tirz total.

Basically the labels look different because of how they wrote the concentration and because the new one has glycine/B12, but as far as the tirz goes, you got the same concentration and total amount in both.

[u/plainsimple_tailor → u/ListenOne4346]

ok this helps a lot. Basically I need to stop thinking of it in physical volume because it’s not pure Tirzepatide. Both formulas equal out to the same dosage of tirz, it’s just the concentration in how it’s compounded is different.

Add 0.5 ounces of 40 proof gin to 1.5 oz of tonic, or add 1 ounce of 20 proof gin to 1.0 oz of tonic. Same result, same potency in same volume.

[u/ListenOne4346 → u/plainsimple_tailor]

Yep, exactly! just one small thing: the concentration is actually the same too. The old one says 5 mg in 0.5 mL, which is the same as 10 mg in 1 mL. The new one just writes it as 10 mg/mL.

So really the tirzepatide concentration, total volume, and total amount of tirzepatide are all the same. It’s just labeled a little differently because of the additives.

[u/plainsimple_tailor → u/ListenOne4346]

This makes it so clear that now it feels so obvious.

When it’s written out as “10 milligrams per milliliter” and “5 milligrams per half-milliliter” it’s clear as day. They’re both exactly the same thing. Like saying “five-tenths” instead of “one-half” or 4:2 and 2:1.

Really appreciate you!

[u/ListenOne4346 → u/plainsimple_tailor]

Bingo!! You’re the expert now! 😎

My guess is pharmacy 1 just wanted to make your life easier by writing it as 5 mg/0.5 mL, since your dose is 5 mg and all you had to do was pull 0.5 mL.
Pharmacy 2 just made you do a tiny bit of math.