14 days ago I made a concerted effort to quit drinking and simultaneously started taking L-theanine to help. In the first few days I noticed high doses of L-theanine (300-500mg+) actually had a noticeable psychoactive effect on me, but this lessened after about a week once tolerance set in. A pleasant relaxation, notable anxiolysis, with a very slight disso like touch to it (it's a partial NMDA agonist). It effectively stopped all my alcohol cravings. I wouldn't describe it as a buzz, maybe very slightly, but it was very noticeable and enjoyable, certainly not placebo. I continued taking it daily in the morning with small redose in the afternoon, 500-600mg per day. It lasts a very long time, over 8 hours, well past it's half life.
I slipped up and drank 3 times during the last 2 weeks. There was a very noticeable potentiation in the effects of alcohol, not the first few drinks but later on. I noticed I was much more drunk than usual with my standard dose of alcohol, and I was blacking out. Now, I'm an alchy and extremely familiar with how alcohol effects me and how I should feel after a certain number of drinks. Obviously it's difficult to really quantify such a thing, but again, I know my alcohol. There were no other factors that had changed and I didn't even smoke weed while drinking which I usually do.
Last night I drank significantly less than usual and I was surprised to black out, I didn't even finish drinking all my beer which is VERY abnormal for me, woke up fully clothed on the couch in the living room (I have no idea why I didn't sleep in my own bed). I'm guessing I walked to the kitchen and for whatever reason couldn't make it back to my room and passed out on the couch. Not unheard of behavior for alcohol, obviously, but this is very unusual for me... almost never happens. I also noticed that my resting/sleeping heart rate was over 100bpm when I woke up... alcohol leaving your system increases heart rate, I know, but I found this somewhat alarming and a lot higher than usual (no other drugs involved). Took some propranolol and it went back down.
TL;DR:
Anyways, it has become clear to me that L-theanine is potentiating the alcohol in me. Yes, since reducing my intake my tolerance has gone down somewhat, but again I'm extremely familiar with where it should be and how it effects me. The amount of beer I drank last night has NEVER caused me to black out like that. Brown out, sure, but not like that. I drank so little that I did not even have a hangover which increase the unusual nature of last night.
I cannot find any information about alcohol + L-theanine interaction on google other than reports that it is generally safe to combine, and that L-theanine can actually reduce the damage alcohol has on the liver.
I'm assuming that L-theanine may be upregulating GABA and that may be the cause (have been taking it daily for 2 weeks in high dose), I don't think it's a direct interaction, but I could be wrong. Or maybe it's effect on glutamate or possibly even it's minor NMDA effect. Maybe all 3... ?
Anyone know anything about L-theanine or this combination? I'm curious if it would also potentiate benzos.
Overall, it's not a massive interaction. I would say it's potentiating alcohol by about 15-30% or so. Other than increased effect I did not notice any other signs of interaction or side effects.
This is not really a desired reaction, I am committed to quit drinking, I'm just curious as to what's going on.