IMHO, my opinion and what i do, not a doc, i am lucky to get my shoes on the correct foot most days, but i have played with this a good amount.
Take 2 ML of bac water and put into vial. Each ml is 5 mg of pt-141. you want to start off at 1-1.5 and maybe even 2 mg if you feel daring. I would start at 1mg and go up from there.
If you want 1 mg then use a slin pin and put in 1/5 of a ml or in this case 2 iu of liquid pt-141, this will give you 1 mg of 141. Shoot subcutaneous only under the skin and in a few minutes you will feel flushing, possible gut gurgles, and then not long after, just rub your head of your dick across anything in the world, whamo, blamo, rigid erection and often increased girth and length.
Will last over night and next day.
With 2 iu's, i am golden for 3 days give or take.
Do not wear gym pants or baggy shorts as its like being a damn teenager and the boner can come from nowhere and surprise yourself and anyone around, if you have a dick of decent proportions...
I know i sound like a dweeb, but i am in a good mood and not feeling scientific in my explanations. But true words are typed above.