L-theanine is Effective in Lessening Positive Symptoms, and improving Sleep Quality in patients with schizophrenia

L-theanine is an agonist (meaning enhancer) for the synaptic transmission of gamma amino buteric acid (GABA), which is a well-established inhibitor of dopamine transmission. So. It makes “sense,” at least, that it would produce the effects several people have described to me elsewhere, including “calming,” “soothing” and at least “lowering the volume” of and/or “slowing down” racing thoughts.

See the following (and more) at

“Several lines of evidence from post-mortem, brain imaging, and genetic studies in schizophrenia patients suggest that Gamma-amino butyric acid (GABA) deficits may contribute to the pathophysiology of schizophrenia. Pharmacological induction of a transient GABA-deficit state has been shown to enhance vulnerability of healthy subjects to the psychotomimetic effects of various drugs. Exacerbating or creating a GABA deficit was hypothesized to induce or unmask psychosis in schizophrenia patients, but not in healthy controls. To test this hypothesis, a transient GABA deficit was pharmacologically induced in schizophrenia patients and healthy controls using iomazenil, an antagonist and partial inverse agonist of the benzodiazepine receptor. In a double-blind, randomized, placebo-controlled study, clinically stable chronic schizophrenia patients (n=13) received iomazenil (3.7 μg administered intravenously over 10 min). Psychosis was measured using the Brief Psychiatric Rating Scale and perceptual alterations were measured using the Clinician Administered Dissociative Symptoms Scale before and after iomazenil administration. These data were compared with the effects of iomazenil in healthy subjects (n=20). Iomazenil produced increases in psychotic symptoms and perceptual alterations in schizophrenia patients, but not in healthy controls. The greater vulnerability of schizophrenia patients to the effects of iomazenil relative to controls provides further support for the GABA-deficit hypothesis of schizophrenia.”


I took one during the day in addition to the one in the evening and my day was definitely easier. I’ll probably do that from now on. It gives me a break from ‘obession’ like thinking for a while.


100mg or 200mg is the common dosages. Its a great sleep enhancer. So is Glycine and Magnesium. I’ve been using 100mg but some have reported 200mg at bedtime as highly effective. Other have said 100mg is a better dosage for them.

Anyways, there are also reports that this combined with caffeine improves your performance on mentally challenging tasks … makes you sharper.

Its also interesting that this is given to cats and dogs to help calm them as well. The peeing dog and cat problems … this might work.



Anybody taking 250mg/day that can report back on how it impacts them?

I’m taking 200mg a day now, up from 100mg a day. There doesn’t seem to be a long lasting effect by which I mean the effect wears off immediately if you stop taking it. The effect is dramatic for me when it comes to sorting out my thinking. I take 100mg on waking up, it kicks in about 90 minutes later. I go from hellish thinking to sanity in 90 minutes like a light switch. The effect lasts for maybe 6 hours, then I take another 100mg.


I take 200mg twice a day. It has certainly helped sleep. Also during the days I am finding it easier to leave the house. Funny thing is when I first took I thought ‘this feels like clonazepam’. Notmoses then went on to say this works on the same receptors. And as far as I understand it is non-addictive.

So my current supplement regime is:

50mg pregnenolone in the morning
3G lysine twice a day
1g of sarcosine twice a day
1g of NAC twice a day
200mg of theanine twice a day
1 multivitamin/multimineral a day

I am very happy birthday with this cocktail. I mean for me it is no substitution for normal aps but compliments them very well. But I don’t think I will add anymore on - think this is enough for now. Cost me just shy of £40 a month for all these but I think it is worth it.



How long have you been on this current supplement regime?

I find it really interesting because you are taking basically all the supplements that have good evidence behind them as being helpful.

Hey admin. Been on this combination for about 4-6 weeks now. Found out about them from this site.

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@ jimbob has it helped in negative symptoms of sz…

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I really think it has. Firstly domestic duties (cooking, cleaning washing) have improved significantly.

Cognitively I have noticed I have been able to express myself more. I can use precisely the right words to share my thoughts. I wasn’t expecting this but it is definitely an area of improvement. I still have a problem with concentration - can’t watch a movie for more than 15mins at a time.


have u tried yoga accupunture meditation mind fullness and Ayurveda…helps in concerntration…

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Had a bad experience with L-theanine. I took 400mg, felt slightly more relaxed that day. Next day however, I felt very irritated/agitated. Tried it again a week or two later with the same outcome.

It’s weird because other gaba agonists (benzos/picamilon) never caused me agitation.

But that’s just my experience with it…

Hi - the recommended dose is 250 mg/day. Did you try it at that level?

400mg is way too much in my experience. At least in one go. I now take 200mg when I wake up and I find that a bit heavy, I take another 100mg when I feel the effect of the 200mg has worn off (around 6 hours later).

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@SzAdmin if you have access to the whole study, can you please check to see if the study was double-blind or not?

I don’t think the first study above mentioned was double blind - but there are other studies of this amino acid in schizophrenia that are double blind. Here is one:


Sir I have a shizophrenia patient in my family.We are treating her with olanzia.But now it does not seem to work.It has no effect on her.Her left eye has become red like blood she feels pain in her eye to.I shall be very thankful to you if u can tell me what should i do…

You should explain this to her doctor and they will adjust / change their medication. Not all medications work for everybody. Everybody reacts differently to each medication. It’s trial and error.


Thank you, I have been wanting to take supplements, but not know what to take. Was considering, vitamin D, Zinc and … mmmmmm, I forget, but this does look like a very interesting option. Happy lady. Think I will try it. My only concern is that I take an unti convulsant for epilepsy and would want to have a reaction between the two. Am hoping it will be ok though, as it is calming. Thanks! x


CAN YOU SUGGEST ME A MEDICINE FOR HER?BECAUSE she will not go to the doctor.She thinks every body is against her…

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