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Faster Acting More Potent
by bladeofreality
Citation:   bladeofreality. "Faster Acting More Potent: An Experience with Fluorophenibut (exp108165)". Aug 4, 2016.

250 mg oral Smarts - Fluorophenibut (liquid)


This is a report for first-time use of a new gabaergic research chemical, F-Phenibut (CAS 52237-19-1). This is a derivative of Phenibut fluorinated at the para- or 4 position of the phenyl ring. It is very similar in structure to Baclofen, substituting a fluorine atom in the place of chlorine.

The result is a drug that maintains both the gabaergic and dopaminergic qualities of Phenibut, but appears to have a several-fold increase in potency, a faster onset (one half hour vs. four hours), and a limited duration of action (4-5 hours vs. a day and a half).

I obtained 2 grams of the hydrochloride salt from a US-based online nootropic vendor who recently added this to their product list, and the package insert indicated it was of Chinese manufacture. It came as a free-flowing, very fine white powder with no odor.

A little background--I am a several year user of Phenibut, have developed a mild tolerance, and take about 2 to 2.5 grams (20mg/Kg) every other day. The dopaminergic 'mood enhancing' effects have long faded away, but the anxiolytic effects have remained strong. My tolerance has gone both up and down at times, though I have always used the same supplier. On occasion when I've skipped doses or taken breaks I've had mild withdrawals, chiefly anxiety, depression, and insomnia, rarely lasting more than five days. The only side effect I've noticed are occasional extremely vivid and detailed dreams that feel completely real while they are happening (though no awareness that one is dreaming, alas.)

When I heard about F-Phenibut, I was intrigued by the initial reports of other users and decided to compare its effects in place of my regular dose of Phenibut. The following occurred after I had not taken Phenibut for two days, in the morning about an hour after waking.


I measured and weighed a 250mg (2 mg/Kg) dose, dissolved in a half glass of water, and drank it all at once, on an empty stomach. There was a weak but noticeable taste that would probably have been unpleasant if the dose were stronger or less diluted.


The first alert came as a noticeable 'change' in my thoughts, a calming effect familiar from Phenibut.


Very obvious onset of relaxation, calm, and focus. And, to my very happy surprise, a light euphoric 'this is going to be a great day' lift just like I remember from the first few weeks of Phenibut use. I began my work day and was able to do analytical thinking, engage with clients, and get into the usual flow quite easily.


Fully developed. Normally for me, with Phenibut, there is a 4 hour onset before the first alert, and an hour or two after that to reach maximum effect. F-Phenibut acts fast.

There is a increased appreciation of music I don't remember from Phenibut.

No effect on motor coordination or speech that I can tell (except for becoming very chatty).


I can tell it has peaked.


The main effects are over, though there is lingering calm, like the next day after a Phenibut dose.


I realize that I am back to baseline, and have been for a bit, but hadn't noticed.


I don't normally crave my Phenibut doses, but here there is somewhat of a 'that was great, let's do it again' feeling. (I don't.)


The overall experience was very similar to my usual 2 gram dose of Phenibut, except all crammed into a few hours instead of a day and a half. The faster onset indicates more rapid crossing into the brain and the shorter duration may indicate more rapid metabolism. The approximate 8-10x increase in potency means less drug to take, but with something like this it's not that important. The dopaminergic rush was light but very pleasant, and is likely to wear off with repeated use.

I've yet to see if this impacts my sleep or if there will be an onset of Phenibut withdrawal, but so far no.

Also, I don't have a feel yet for how frequent to dose this or what withdrawals would be like. I can find no information on human half-life or other pharmacokinetic parameters.


I see Phenibut as a something to take regularly to benefit from its great anxiety reducing effects. F-Phenibut seems more 'tactical', something one would take prior to a stressful event and have it wear off soon afterwards.

Exp Year: 2016ExpID: 108165
Gender: Male 
Age at time of experience: 48 
Published: Aug 4, 2016Views: 13,848
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Fluorophenibut (754) : First Times (2), Not Applicable (38)

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