My compounded sema journey — 12 months, 6 pharmacies, lessons learned

Wait I'm confused. My vial says 3mg not 5mg. Do I just use the same formula?

Previously posted:

My vial says 3mg not 5mg. Do I just use the same formula?

Same exact formula, just different numbers. The universal formula is:

Volume to inject (mL) = Desired dose (mg) ÷ Concentration (mg/mL)

And concentration = Total mg in vial ÷ mL of BAC water added

So for your 3mg vial, if you add 1.5mL BAC water:

• Concentration = 3mg / 1.5mL = 2mg/mL
• 0.25mg dose = 0.25 / 2 = 0.125mL = 12.5 units (draw to halfway between 10 and 15)
• 0.5mg dose = 0.5 / 2 = 0.25mL = 25 units

Or if you want easier numbers, add 1.2mL BAC water to get 2.5mg/mL, then 0.25mg = 10 units. Same as the 5mg vial example. The total number of doses per vial will be different of course (3mg total instead of 5mg).

you are an absolute angel. I just did my first reconstitution and injection — 10 units, right in the belly, barely felt it. This community is the best. Thank you all so much!! 🙏🥹

Pinning this thread. We get this question at least twice a week. Excellent explanations as always from our knowledgeable members. For anyone reading this in the future, we also have a reconstitution calculator in the Tools section of the wiki.

And a reminder: always verify your math before injecting. If something seems off, ask here or call your provider. It's never a dumb question when it comes to dosing.