Feeling pretty calm at 1.5g, although I dont know whether I'm feeling the first dose or second dose. I'll have to try this again in a few days and compare results.
Seeing as this is your first time I don't know if you know that Phenibut lasts A LONG TIME, not as long as F-Phenibut, but a long time, and it also take me about an hour and 15 minutes for a dose to kick in, but there are times I've not felt it for 2 hours, so you don't want to jump the gun and re-dose unless you've waited like a good 2 1/2 hours and still don't feel anything.
Once you get a sense for how long it usually takes you to feel it (as everyone is different) then MAYBE you can redose in an hour and a half, but I have never had it kick in in less than an hour and 15 mins.
I would honestly say that on average Phenibut lasts for me for about 18 hours, sometimes even 20 or so max, and when I say 18 hours I really mean I feel high from it that long. I will take it at night at times, wake up, and STILL be on it most of the next day.
F-Phenibut on the other hand would sometimes last me THIRTY hours.
So yeah, be aware that it takes a very long time to kick in and to take it slow, and be prepared for it to possibly last a day, pretty much around 24 hours give or take from your 1st dose, and if you take a few doses then obviously it's going to take that long for each one to wear off, so I would write down when you dose and if you don't know how it will effect you then don't use it if you have something planned for the next day.
I know how it effects me and I feel I can be functional and even drive or do things on doses up to 3 grams, but I certainly wouldn't recommend to go around driving on it if you don't have to, especially not those higher doses as it is a sedative, and my doing so is not necessarily the smartest thing, but at lower doses it can be KIND of like Kratom, not really in how it feels, but in the sense that you can do things like work out, study, play music, talk to people, whatever, and they won't know you are on it and you can be sociable and productive, but if you use too much it will knock you on your ass and you won't feel good, so I'd suggest taking it slow.
And I would REALLY recommend not taking it more than 2 days a week, preferably not in a row, and while my rule for myself is not to exceed 8,000mgs in a week, on the tub it says 4,000 a week, so proceed with caution.
I would say exceeding 8,000mgs a week is playing with fire, even though I've done up to 10,500mgs in a week, but I always write down how many mgs I have taken in a week and what days and times I took them so I always know where I am at until it's a new week and the slate is wiped clean (though I don't consider it a truly "clean slate" till it has been 7 FULL days where I not only didn't take it, but didn't even feel like I was on any left over from the last dose, seeing as it lasts almost 24 hours.)