View Full Version : Phenibut - mechanism of action and alternate methods of consumption

09-08-2006, 02:46
Recently I've begun investigating the relatively little-known substance commonly called phenibut. It's most often classed as a nootropic, and it bears some relation to benzodiazepines. I really enjoy its effects a lot, though it took me a little while to realize them for what they are. I find it to be an excellent mood enhancer, truly excellent, and anxiolytic, though it's not something I'd consider recreational. This is coming from someone who generally dislikes GABAergic drugs, including alcohol, GHB and its analogues, and benzos.

Generally it is taken orally. I've read about how it's almost entirely broken down in either the stomach or liver (can't remember exactly which or how at this point), and it definitely takes a long time to take effect, 3-4 hours for me. At a dose of 1 - 1.5 grams (depending on tolerance), it takes full effect in 3-4 hour hours and lingers all day, generally just improving my mood significantly and sometimes giving a little buzz. The mood lift sometimes becomes a very natural-feeling euphoria, as if I had just heard the greatest news or gotten a bonus at work or had really good sex.

My question is, does anyone know anything or speculate on any alternate forms of ingestion? There is one report on Erowid of snorting it, but it's not enough for me to try it. It claims that it's active in far, far lower doses that way, which would be nice since 1.5 grams is quite a lot. I believe the report claimed it's fully active in the range of 20mg or something. Does anyone know anything about its mechanism of action? I speculate that it might also be very effective rectally, which would be a preferrably form of ingestion over insufflation. I'm nervous to try either because I have no clue as to what kind of dose would be necessary, and having too much causes extreme sedation, dizziness, and the like.

Any speculation, discussion, or outright experience would be much appreciated. Thanks!

09-08-2006, 04:11
I'll speculate that no drug should be (or is) 50 times more potent when taken up your nose rather than by mouth. That 20mg report does seem sketchy.

Sorry, besides that I have nothing useful to say, never tried or heard first hand about phenibut

09-08-2006, 08:32
Well, try 20mg rectally :) . Rectal is more slowly absorbed than insufflated, so even if that 20mg report is accurate (I HIGHLY doubt it) then you're in the safe zone anyway.
Slowly build up your dosage till you find a nice comfortable level, then come on here and tell us all what it is as a mg/kg dosage :) . I'm really interested in this compound too :) .

09-08-2006, 23:54
I have tried it and my experience has been a bit different from yours. As far as I'm concerned it's a reasonably effective muscle relaxant but it doesn't do much else for me. I don't really find it euphoric at all.
I've wondered if lactamating the molecule would significantly alter absorption, but that's probably more trouble than it's worth.

Dr. Beat
10-08-2006, 08:10
I dont know if this helps, but i find Piracetam is about 10 times stronger if I put it under my tougue and let is dissolve over about 5-10 minutes, compared to swallowing.

10-08-2006, 21:49
You mean phenibut, or do you actually mean piracetam? And for reference, I take all of my nootropics and phenibut by dissolving them in water. I'm not sure I could put them under my tongue and absorb sublingually because they taste so bad, particularly phenibut. Talk about sour!

hussness: Yeah, phenibut is weird for me. Sometimes it'll make me very euphoric and other times it's like a long-lasting benzo. Also my reaction to it has generally been more positive than most. I achieved a very strong, wonderful bliss from it once, but most of the time it's just a general mood tonic for the day, which is nonetheless quite effective.

I guess I'll have to become a guinea pig to find out what I seek. If I do, I will certainly contribute my experience to the common good.

11-08-2006, 03:50
do not snort this stuff!!

I had over 100+ grams sometime back and was playing around with snorting it. yuck, it really gives you that nasty hangover effect that phenibut can have, and its not any better than taking orally. trust me on this one.

13-08-2006, 19:55
think i read somewhere the ph of phenibut dissolved in water was around 2.5, would a little base need to be added before IMing if one were to try that?

I wonder how soluble it is, - how much you can fit in the least amount of water.

13-08-2006, 20:42
So, definitely, the way to go with phenibut is ordering the bulk powder instead of the capsules?

13-08-2006, 23:21
Um, yes, absolutely yes. Getting anything in capsules is a big waste of money. The markup per dose is quite large, even tremendous.

01-09-2006, 18:31
Anyone know what a reasonable dosage range is for this drug? I think the fact that it is advertized on nootropic sites tends to give the false impression that it has a ridiculously high therapeutic index (like a lot of supplements, even if they're not therapeutic). How does it compare to baclofen?

03-09-2006, 19:58
1-2 grams, from what i can remember, seemed to be a good healthy dose to get positive effects.

23-03-2009, 19:46
I speculate that it might also be very effective rectally, which would be a preferrably form of ingestion over insufflation.
Well, it took a couple of years, but you've finally found a person who has taken Phenibut intrarectally!=D I quartered my typical dosage and plugged a gelcap and some water- for dissolving purposes. I don't believe I felt any effect at all... except for the unpleasant sensation of having a lot of chemical up my ass. I don't plan to try again, and I don't advise anyone to try either. I'll stick with oral consumption.:)

I've read about how it's almost entirely broken down in either the stomach or liver (can't remember exactly which or how at this point)
Does anyone know which?

24-03-2009, 01:42
Go figure, what a terrible way to go about it. There are primers around teaching you how to administer something intrarectally.

Dissolve in water, suck it up in an oral syringe. Lube syringe, administer. Laying belly down for 20 minutes can help avoid that 'oh god, gotta shit, but not yet' feeling.

24-03-2009, 02:27
I know for a fact too that Xorkoth has plugged phenibut in the past with positive results (and still does as far as I know), their's a thread kicking around about it.

I tried it once with an oral syringe, but used too much solution so it ended up coming out the way it came unfortunately. I'll have to try it again with a more concentrated dose in about 1cc or so. Sure is a weird chemical, fun in doses at about a gram or less.

24-03-2009, 03:14
Go figure, what a terrible way to go about it. There are primers around teaching you how to administer something intrarectally.
Are you saying my information on this substance is invalid just because of my method? I'm no intrarectal expert, but I've used the same method I described for other substances with success. Go figure nothing.:p

Gaian Planes
24-03-2009, 04:08
I have also plugged phenibut. It comes up much quicker (like think 30 minutes compared to 1-2 hours orally). You need about half as much as your regular oral dose (the sweetspot will vary for each person because our GABA systems are quite different sometimes).

Its a sloppy drug really. Habit forming. Withdrawals when you stop after multiple use. Joint pain with regular use. Dehydration is easy with regular multi day use. Caution is needed just like with GHB.

I plug about 500mg of it when I used it. I don't use it anymore though because it is false sense of security (like all benzos and GABAergic drugs). I prefer to be sober and deal with anxiety as it comes and perfect my coping skills than take a drug to do that work for me.

I will say this: ain't no sleep like a phenibut sleep. Well, high dose zinc+high dose melatonin approaches the deepness you get with phenibut (but not quite even!).

Just me though, ymmv.

24-03-2009, 08:49
I've had good luck with approximately .75 g administered rectally.
It seems to be easier to hit a recreational dose that doesn't induce nausea through rectal rather than oral administration.


24-03-2009, 14:55
^ that is still a large dose relative to the oral intake averages

what for you if you know does it most closely resemble in effect for what would produce same basic effect (though as you noted with sides) taken orally?

24-03-2009, 17:10
what for you if you know does it most closely resemble in effect for what would produce same basic effect (though as you noted with sides) taken orally?
This is tough to answer since responses to this substance are so varied. Also, as GP noted the sweetspot will vary for each person because our GABA systems are quite different sometimes, in terms of dosage. For this reason, I don't even want to suggest a dosage; anyone experimenting with this compound should start low.

I have witnessed four different people ingest this substance.

Person A, who is quite sensitive to the hypnotic effects GABA A agonists took a lower dose (adjusted to weight) than the others. All he experienced was sedation and a desire to sleep. No "recreational" effects, or nausea was noted.

All other people took the same dosage.

Person B experienced substantial mood lift, without any depressant effects, followed hours later by violent emesis.

Person C, who often has unusual responses to drugs, experienced altered mood, mostly for the positive, and sedation. He likened the experience to a low dose of DXM. No nausea was noted, although he did have an urge to defecate.

Person D is me. I have a bizarre, inborn, insensitivity to GABA A sedatives. I have also ingested this substance many times, with a wide range of experiences. Usually it is a eugeroic, a mild mood enhancer, and an effective nootropic. I experience no sedative or depressant effects although about on in three in times, I become very sleepy many hours after ingestion. Also, about one in three times, I experience nausea and occasional emesis hours after ingestion. The other third of the time, I don't perceive any strong effect at all--food intake prior seems to be important in this regard. A prominent side effect that I usually get is a sensation I would liken to akathisia.

Persons C and D take several psychiatric medications, so those results may be atypical.

Tolerance builds very quickly (I can elaborate on time if anyone wants), and for this reason, I believe Phenibut is not abusable--even for those who enjoy the effects.

Neither I, nor the other three people I have mentioned have every tried GHB or its pro-drugs\analogues, so we cannot compare. However, although they are both GABA B agonists, GHB hits the excitatory GHB receptor, which Phenibut does not. From almost every experience report I have read, people who have tried GHB state that Phenibut is very unlike GHB is most aspects.

24-03-2009, 18:32
In doses over 1 gram (sometimes up to 3 grams throughout the day, not often however) I would wake up with the drug kicking harder and more intense than before I had gone to sleep (perhaps 6 hours earlier). On these high dose occasions I noticed quite a few odd side effects, such as narcolepsy, a strange electric current feeling that would pass sporadically throughout my body (much like the 'brain shock' phenomena experienced during SSRI withdrawal), and an odd symptom that would cause me to randomly drop an item I was holding in my hand. Also experienced an intensification in ADD-type symptoms.

First time I noticed this, it felt like a mild MDMA type feeling, an afterglow of sorts. I remember walking around town in the most beautiful of moods the entire day, despite the occasionally unpleasant side effects.

At doses below 1 gram it felt like a very natural feeling of well-being, as though I hadn't taken anything at all, but was in a great mood for 24 hours nonetheless.

24-03-2009, 18:37
Can confirm that similar effects from largish doses phenibut kicking in hard many hours after ingestion and after a good night's sleep. Brain zaps, intense brainfog. First time it was quite nice, after that only very uncomfortable.

24-03-2009, 21:42
I'd stick with substance-D. ;)

what for you if you know does it most closely resemble in effect for what would produce same basic effect (though as you noted with sides) taken orally?

Unfortunately, my experience with other GABAnergics is limited to benzos, alcohol, and ambien. I would say that phenibut resembles a 'cleaner' version of alcohol, or a 'more intoxicating' version of benzodiazapines. However, the gradient between 'too subtle' and 'I feel sick!' is irksomely thin. I should also note that I have approached the substance solely as a recreational drug, never attempting therapeutic use.

I would say that the potency is roughly doubled in comparison to oral administration, and the duration is reduced by perhaps 40 percent, which I think is a good thing.


25-03-2009, 00:32
thanks for sharing :);)

08-04-2009, 01:35
Are you saying my information on this substance is invalid just because of my method? I'm no intrarectal expert, but I've used the same method I described for other substances with success. Go figure nothing.:p

Yes. Just like any study with poor methodology, if you didn't administer it properly, the results are useless. Having had past success (unless we're talking huge numbers) doesn't indicate that your no-effect isn't the result of poor absorption.

This is basically the same as the people who don't know how to plug properly, just shove a pill up there and get no result. These are the same people who would get mocked for doing such a thing in OD or (when it was alive) TOTSE. Your adding water up there at least gave it a chance of working, though if you take a gelcap and just it in a glass of water, it takes quite a while to break down- much less absorb. I sat a benedryl (generic pink and white) gelcap in a glass of water and a glass of vineager. The vineager opened up after about 10 minutes (I checked between 8 and 10, so it was somewhere in there) and the water pill at 17 minutes now still hasn't opened. This was warm water, probably 80-90 degrees, which is probably lower than what you'd have in the rectal cavity, though. I'm sure others here have done similar experiments; this was always the first thing I did when I had new gelcaps that I was adding herbal extracts to (to better guage when to expect onset). I've added a pill to hot water (~130 degrees F by my thermometer, cooled down a bit after boiling some to quick melt a bag of baby milk, it's sure to drop a lot before it opens).

The stomach is always moving around and is very acidic, so a pill won't last long. The rectum isn't either, and it's quite possible that whatever water there is will be absorbed before the pill breaks open. It's pretty impossible to figure out if it has broken or not because it's so likely to break open when it is expelled from the body.

Judging from the results others have had using better designed methods, it seems most likely that the lack of positive result is not due to inactivity via this route but due to a lack of absorption using this method. Not definitive, of course, everyone could be experiencing placebo effect, but that doesn't seem all that likely given the long study of the drug.


10-04-2009, 19:55
ummm...yes. It appeared to work when I prepared a (most saturated) water solution...just shoving gel-caps up one's ass will at best induce a 40+ minute delay of onset and at worst waste drugs entirely.


10-04-2009, 20:31
^^^How long until onset via the rectal route? Dose?

11-04-2009, 01:14
for me: .75 mg.
Onset in ~20 min, but peak still a couple hours later.

11-04-2009, 01:59
.75 grams?

11-04-2009, 15:38
ummm...yes. It appeared to work when I prepared a (most saturated) water solution...just shoving gel-caps up one's ass will at best induce a 40+ minute delay of onset and at worst waste drugs entirely.


not in my experience

gelcap is actually my preferred way to administer drugs rectally now. Its much less messy. Although I probably would still do solution for phenibut (if I used the tempting stuff anymore!), because of the volume of the drug.

A gel cap melts in your ass REALLY quick ime (like 5-10 minutes). I can tell this because I can feel the tingle within minutes of the release of drugs that make your bum tingle (like 2CB).

Maybe some people here just have a cold bum? =D

11-04-2009, 17:49
.75 grams?

Yes. Sorry. :)

gelcap is actually my preferred way to administer drugs rectally now. Its much less messy. Although I probably would still do solution for phenibut (if I used the tempting stuff anymore!), because of the volume of the drug.

almost graphic:

Having shat out undissolved gel caps before, this is not a risk that I'm willing to take. :)


13-04-2009, 12:48
rectum is not stomach so dont expect your arse to digest but do expect it to absorb liquid which is its primary biological function.

end of

15-04-2009, 23:52
one means of improving the function of plugged gelcaps is to perforate the gelcap multiple times with a pin or similar instrument prior to insertion.

07-04-2011, 13:06
Just necroing this old-ass thread (pun intended, what with rectal insertion and all, lol) to say that I'm on 2.5 grams of phenibut right now, ingested 1H 50min ago. It's a subtle euphoria with a not so subtle mood lift and relaxation. A person on IRC, when I mentioned my dose, asked "how did you manage to take 2.5g and still manage to type here? I took 1.5 g once and kept going unconscious for hours, and I took it over 5-6 hours. How are you still awake?" So I don't know, phenibut is weird. It's not 1H 55min since ingestion and I'm not feeling like I'm going to pass out. Maybe I'm one of the people who don't peak on it before 3-4 hours in. I might pass out in five minutes. Who knows?

Edit: oh right, the whole point of this post was to say that it feels like tiny snorted doses of 5-10 mg boost the effects a bit, enough to be noticeable. I don't think the "50 times as potent" claim is true, but I wouldn't be too surprised if it turns out to be 5-10 times as potent insufflated compared to orally.

27-04-2011, 06:07
PH would make rectal admin feel like the ill aftereffects of eating 10 habaneros...
But IN roa is really NOT that bad.

I really liked the psych horse kick to the brain that blowing 15-20mg of 2c-I gave, one ill advised nasal consumption of Zoloft(thank you harold and kumar...) burned for 5-6 hours after cleaning my nose, fucking dipenhydramine too

Doing phenibut in small nasal bumps is not bad. the burn subsides really quickly. I don't know about getting a whole dose in...but for the naysayers, it would be worthwhile to see how IN consumption spread out would affect the phenibut experience.
For most, in other words, those who enjoy the nootropic effects, this would not be worthwhile.

27-04-2011, 17:34
Hmm, interesting. I read the erowid reports and I am curious about this compound. Sounds like its slow acting and lasts a while. So does anyone know the half-life of this compound and what enzymes break it down? Anyone have experience with combinations of this compound and others that might give some insight into what its doing in the body/brain?

28-04-2011, 03:07
half life ~5 hrs via wiki, enzyme activity unlisted. It is rapidly absorbed through nasal tissue as evidenced by the quick abatement of burn, from there quickly crossing the blood brain barrier--idk?
I consider it a bad experiment other than to refute all those who say it's really bad to snort as I was on an oral dose consumed earlier.
(blowing zoloft really blew half of my day on spring break in NYC, this stuff only robs 30 seconds of pain free living. 2ci burns for 20mins; you never notice it stopping though because it numbs the area surrounding and throws you into acid-land...)

12-04-2012, 19:34
Do we have Russian forum members here? Or anybody who speaks a little bit Russian?

I am interessted in phenibut's method of action and wanted to find out more.
But unfortunately there is not much real scientific/medical information. At least not in the English, German, and Dutch internet.
Phenibut was developed in Russia and I think that it is used as a medication there.
In Europe every medication needs to have a package information leaflet. Probably it's the same in the USA.
The package information leaflet contains information for the patient. But there also is an information leaflet for doctors for every medication. I don't know the English word for that.
I read that phenibut made its way to space so that Russian cosmonauts could use it when needed.
So medical use seems to be investigated at least in Russia. They will sure not give their cosmonauts a medication that is not tested and where the effects are nearly unknown.
Probably there will be an information paper with information like the half life time or the mechanism of action. I was not even able to find how this stuff really is working and what happens in the brain. I know that GABA can not pass the blood brain barrier. With the addition of a phenyl ring, it becomes capable to pass the bbb. But what then? Is phenibut broken down to GABA (and something else) when it reaches the brain (similar to picamilon) or has it an other mechanism of action?
Unfortunately I do not speak Russian. I cannot even read cyrillic characters. If I could do so, I would use a Russian search engine (maybe google.ru - does that exist?) and search for such an information leaflet or other medical information.
Is here anybody who speaks Russian? Then it would be great, if you could use a search engine to find such documents. You don't need to translate. When I have links to such documents, I can use different translation programs. Probably those bad computer translations will suffice to get the important infos.
If a Russian or a Russian speaking person reads this, then please spend a minute of your time to google and post some links. Thank you.

12-04-2012, 19:40
http://ru.wikipedia.org/wiki/%D0%A4%D0%B5%D0%BD%D0%B8%D0%B1%D1%83%D1%82 ???

13-04-2012, 04:01
I'll give my two cents on phenibut.

Orally administered it has issues. Very poor absorption into stomach acid, so your body in my experience absorbs roughly 0.5 grams an hour, the rest of it just sits undissolved in your stomach acid (low saturation point at such low pH, I know this from puking up the undissolved phenibut). This can lead to massively overdosing (thankfully it's not very toxic), one night I remember probably taking 7 grams all up (kept taking it cause I wanted to feel it more, but higher dosing does not make it work any faster, however when intoxicated its easy to get carried away) and the last thing I remember is having a shot of bacardi 151 at a bar, then waking up on the side of a road in an incredibly out of it state (I wasn't even concerned by the fact that I woke up on the street, at the time I didn't give it a second thought - it's a very good anxiolytic indeed!) - absolutely zero recollection of the events in between. I found by changing it from it's acidic form to a sodium salt you can increase oral bioavailability quite significantly, and it tastes much less nasty as a salt so it's easier to mix into a drink.

Intranasally, it is definitely more bioavailable and requires much lower doses, but it fucking burns like a bitch. Even when I prepared the sodium salt there was still some acidic phenibut left and it doesn't take much to set off your mucous membranes. Mind you it's not as bad as 2C-X up the nose.

Effects wise, the first night I've taken it I've never found it to be that great, just sort of a pleasant, relaxed, clear-headed drunk - a great potentiator for alcohol though (and I would assume other GABAergics). However if you go binging on it for a few days, it gets better and better each day, more and more euphoric. However, when you stop binging, your short term memory is completely fucked (I mean completely) from too much GABA stimulation, although taking a little phenibut again can ease this - I find picamilon to be a good antidote to this as well. A days rest though and you're back to being able to function normally again.

Overdoses on this aren't fun, it basically forces you to lie down because the headspins get crazy fucking intense and last for aaaaages. You will get a good 12-16 hour sleep when you od though haha. That reminds me as a sleep aid, nothing comes close to phenibut in terms of quality of sleep. Just don't take more than your body can process before you wake up (for me 2 grams max, taken a couple of hours before bed, ymmv), otherwise you'll wake up quite fucked indeed.

Never tried administering it rectally, might do that next time I get some.

13-04-2012, 04:35
Interesting. I've been reading up on phenibut for the last several days. I'm mostly interested in its recreational use, but I also suffer from depression and generalized anxiety disorder, and I wouldn't mind taking low dose phenibut every now and then for its anxiolytic and mood lifting properties. I'm going to try it Saturday with some friends. I've been on Suboxone maintenance therapy (8 mg buprenorphine/day) for almost a year, and this worried me at first because of possible respiratory depression. However, I have a pretty strong opiate tolerance so I'm not too concerned. I also take Klonopin for anxiety (usually 4 mg/day) but I stopped taking it today (took Xanax instead) so that there will be a washout period for the benzos before I take the phenibut. I'm going to try 500 mg to assess my tolerance and go from there, but I probably won't go past 1.5 g max (I'd prefer to stay at 1 g or below to avoid any negative interactions). Will try having a few beers once it kicks in, and maybe take a small benzo dose to see if gives any potentiating effect (assuming I'm not already wasted by this point). I'll let you guys know how it goes.

13-04-2012, 14:36
I really liked the psych horse kick to the brain that blowing 15-20mg of 2c-I gave,

Yeah me too, especially when sleep deprivation set in because I still couldn't sleep 20+ hours after taking it (at 2 AM mind you) and 12+ hours after the effects had worn off. Sorry, off-topic.

15-04-2012, 17:42
http://ru.wikipedia.org/wiki/%D0%A4%...B1%D1%83%D1%82 ???
This was my first attempt. Russian wikipedia. but unfortunately not the information I was looking for...

For European medications there are two information leaflets (Probably the same for USA medications). I don't know the exact English words for this.
One is the "medical package information leaflet" (instructions for the patient) which is delivered with the medication. And then there is an "expert information" (information how the medication works for e.g. doctors).
In the second one there is information to find like the half life time of a medication and how it works in body or brain. information that is not important for the usual patient.
I tried to find something like that because phenibut is not only sold as dietary supplement but also as medication in Russia.
If I would know the Russian word for this "expert information" then I could use google to find and translate it.
The Russian word for "Phenibut" is "Фенибут". I tried to use a translation website in order to translate "Fachinformation" (German for expert information) to Russian. Result was: КСП. Which seems to mean PCB to me. Don't know too many cyrillic letters. Probably an abbreviation...
But google didn't give me the wanted information when I asked for "Фенибут КСП".
Then I tried to translate "half life time" and got "период" as result. But again, a google search for "Фенибут период" gave me not the wanted information.
I found a lot of websites which I all translated with http://translate.google.com but I didn't get what I was looking for. Why does nobody speak Russian here..?

20-04-2012, 04:10
Note I am dependant on benzos, which could have made this reaction only occur for me, but if I'm on phenibut and I vaporize DMT... my consciousness constantly skips along with my thoughts hmm.... like my thoughts and such are a fractal tree branching in different directions and every time it branches off.. BAM a slight zap and feeling of consiousness "resetting" immediately and each time my whole state of mind has progressed.. it is most obvious with vision where what I am directly focusing on will change with out any frames in between or even experiencing the same exact frame like 5 times in a row.

Basically imagine every "thought/specific state of mind/everything you see" brings its own consciousness and in order for a progression to happen, instead if a smooth transition like normal, if your mind just felt like it was resetting instantly with every change while the transition is completely gone. Almost robotic in hindsight.

Anyway I doubt this helps that much, but phenibut is definitely unique with its interaction with dmt for me and I've tested this 4-5 times(it's not a pleasant experience and it really really made me question how much of my consciousness is "real" and how much is merely an illusion of conscious choice, control, and constant attention, but it is very interesting to experience and you won't really understand I dont think unless you've been there). So if anyone is daring enough to try I'd be interested if it only happens to me, due to benzos or brain chemistry, or if its a result of just the combo. I can vaporize dmt w/ weed, lsd, psilocin, methylone, mxe, pretty much everything except -racetams(mostly piracetam) which remove the dissociation of dmt and make it incredibly overly intense.

So idk I guess I was trying to add some info on phenibut, but it would be pretty hard to gather anything from what I said.