It typically goes:
Day 1: 1 gram
Day 2: 1.5 grams
Day 3: 3 grams
Day 4: 5 grams
Day 5: 8 grams
Day 6: Shit, maybe I shouldn't be taking so much...can't sleep. 10 grams.
Day 12: Damn! Damn! Damn! Why did I ever take this shit in the first place?! Damn! Infinite grams.
Day ?: Withdraw
Day ?: Withdraw
Day ?: I'm in hell!
Moral of the story? Moderation is key. Never take more than once or twice a week. Tolerance builds quickly and addiction is easily obtained. Personally, I'd suggest flushing that garbage down the toilet.
Pretty much what happened to me, except I only took it for 3 days.
The first day I dosed 2 grams. Felt a little relaxed, not much else. 'They' told me it takes a few hours to kick in.
Second day, I became greedy and dosed around 5 grams in the morning, I'll be damned if this chemical doesn't get me buzzed, after all 'they' seem to be getting really high off this powder. Started feeling REALLY relaxed, and 'they' just got another tub of phenibut in the mail. Because my 100g tub was finished between the bunch of them in a day! So then I dosed another 5g twice later in the day. Felt an inexhaustible physical energy, like I could workout for hours. And mentally my IQ seemed to have raised 7 or 8 points, perhaps my focus was just dramatically increased.
The 3rd day I said, why not? And took 10 massive scoops of powder as I had fed the little Asian man (they called him 'Cheese') 30g of phenibut yesterday with no adverse effects. Granted he must have had tolerance. I was now 'rolling' on the third day of my unintended phenibut binge. The effects were as strong as a substantial dose of mdma. I was taking other nootropics to synergise with the 'bute', so I cannot attribute the dramatic effects to the phenibut alone, although 'they' were only taking phenibut and were quite silly off it. They told me I was going to be withdrawaling the next day, because it had already been 3 days in a row of continually dosing. I thought, how bad can phenibut withdrawal be? I haven't even been taking it more than a couple days.
Sometime the next day I felt as though I had entered into a living hell, I'm talking schizophrenic delusions and paranoia, feeling like I could have a massive seizure at any moment (if that's even possible?), and being afraid that if I called an ambulance the doctors (aliens) would kill me at the 'hospital'. I thought the drug I had taken was not phenibut at all, but rather a powder given to me by aliens who then abducted me and were taking me to planet Phenibut. I thought that the reality in front of me was a form of anesthesia the aliens were projecting onto my mind while they were performing tests...anyways enough about that all in all the delusions lasted about a week before they started to subside. I was afraid to tell a doctor what was happening because I knew they would scream schizophrenia, and that would lead to an institution.
All in all, don't fuck with phenibut. Never take more than the recommended dose at the recommended frequency.