I've seen some people concerned with GABA rebound effects from l-theanine due to effects on increasing GABA. Theanine is commonly mentioned as a gaba agonist.
1. Does it actually have significant effects on GABA that would lead to rebound?
2. Would a daily gram amounts be safe for potential serotonin lowering effects?
Looking around i haven't seen much substantial on GABA effects. actually on Theanine Research Breakdown one rat study says it REDUCED gaba, and another said in increased.
But the study that showed an increase only lasted for 30 minutes after taking - then it DECREASED gaba a bit for the remainder of time tested so it didnt last long if this was the mechanism you'd think you'd only get 30 minutes of upside which people dont
imgur .com/5SYooXb
reddit .com/r/ Nootropics/comments/4mcbd1/comment/d3uqdey
think it was about 1.2g / kg maybe ~12g human dose
Also typical doses would be underdosed if going for the serotonin reducing effect. https://www.tandfonline.com/doi/pdf/10.1271/bbb.62.816 brain serotonin went down after 100mg / 100g so 1g/kg. going by this would maybe ~10g human dose for this - i wonder if gram amounts are safe?
this one suggests GABA A receptor activity though Involvement of GABAA Receptors in the Neuroprotective Effect of Theanine on Focal Cerebral Ischemia in Mice
significant GABA agonism / downregulation (especially at typical doses) does not align with schizophrenia studies where 8 weeks of 400mg supplementation showed reduced anxiety (you would expect tolerance/rebound by this time if it was going to right)
I wonder about gram amounts where you see a 30 minute spike which comes back down below baseline. & i guess there are other mechanisms that could see downside / rebound effect annoyingly things are more complicated than 1 angle - so probably not a good idea megadosing grams
edit: this one haidut posted [Effects of theanine on monoamine neurotransmitters and related genes in cerebral ischemia-reperfusion injury rats]. | Semantic Scholar
also showed serotonin lowering with dopamine increasing effect highest at ~1g for human and worked by 15 days [90 mg/kg (6/37)*90 * 70kg = 1000mg , also good effects on less e.g 30mg/kg 333mg] 3/37 for mouse 6/37 for rat
Theanine Stops And Reverses The Stress Reaction (cortisol, Noradrenalin, Dopamine) but 1.5g also reduced baseline cortisol a lot which may not be good for people with daytime sleepiness. maybe lower doses attenuate cortisol response to stress without affecting baseline cortisol too much?
1. Does it actually have significant effects on GABA that would lead to rebound?
2. Would a daily gram amounts be safe for potential serotonin lowering effects?
Looking around i haven't seen much substantial on GABA effects. actually on Theanine Research Breakdown one rat study says it REDUCED gaba, and another said in increased.
But the study that showed an increase only lasted for 30 minutes after taking - then it DECREASED gaba a bit for the remainder of time tested so it didnt last long if this was the mechanism you'd think you'd only get 30 minutes of upside which people dont
imgur .com/5SYooXb
reddit .com/r/ Nootropics/comments/4mcbd1/comment/d3uqdey
think it was about 1.2g / kg maybe ~12g human dose
this one suggests GABA A receptor activity though Involvement of GABAA Receptors in the Neuroprotective Effect of Theanine on Focal Cerebral Ischemia in Mice
significant GABA agonism / downregulation (especially at typical doses) does not align with schizophrenia studies where 8 weeks of 400mg supplementation showed reduced anxiety (you would expect tolerance/rebound by this time if it was going to right)
I wonder about gram amounts where you see a 30 minute spike which comes back down below baseline. & i guess there are other mechanisms that could see downside / rebound effect annoyingly things are more complicated than 1 angle - so probably not a good idea megadosing grams
edit: this one haidut posted [Effects of theanine on monoamine neurotransmitters and related genes in cerebral ischemia-reperfusion injury rats]. | Semantic Scholar
also showed serotonin lowering with dopamine increasing effect highest at ~1g for human and worked by 15 days [90 mg/kg (6/37)*90 * 70kg = 1000mg , also good effects on less e.g 30mg/kg 333mg] 3/37 for mouse 6/37 for rat
Theanine Stops And Reverses The Stress Reaction (cortisol, Noradrenalin, Dopamine) but 1.5g also reduced baseline cortisol a lot which may not be good for people with daytime sleepiness. maybe lower doses attenuate cortisol response to stress without affecting baseline cortisol too much?
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