GHRP6 how to know it's 100mcg in syringe

Greetings everyone.
I've been using ghrp6 from 5 days now and i wanted to make sure if I'm taking the right amount... My ghrp6 is 10mg/flasche
I put 2.5ml of sterile water, using a 1ml syringe that shows 40units.
I've been putting ghrp6 to 3units. Is it 100mcg?
If not then how much actually is?
P.S. I take a shot in the morning first thing after waking up on empty stomach and eat after 30mins.
Second shot at bed time 2hrs after my last meal.

10mg powder/2.5mL dilutent =4mg/mL agent;;
40 units of 4mg/mL (40% of 4mg) = 1.6 mg Is this your question? Or, is this just the way you put the dilutent into the powder?
Not sure I understand your question but, if you want to inject 100 mcg (pretty low) then dilute powder to 1mg/mL, by using 10mL of dilutent and injecting the first large-bold .1 gradation, on the 1mL syringe