For starters, how old are you and how do you plan to use this phero?
And have you read this thread and the threads linked within - The info you need is all there:
Ahh - OK, found your original thread. Mid 30s and you want to use it with a woman (no age given) whom you are physically but not sexually close with.
Gent and M&M’s advice on the original thread is pretty much spot-on but you really need to do some testing as dose depends on a number of individual factors - For which the 1x TUTH would probably be best. If your sweet spot is higher, you can get the 2x as an economy measure later.