Comment · Thu, April 2, 2015 · Ceretropic
A word on caffeine + l-theanine
Original post in this thread
AoE-Priest · 60 points
I know this is like the most popular combo around here, but I like to stay skeptical and avoid falling into groupthink.
So, I was looking at the research index in the side bar. There are a number of studies posted for l-theanine. Unfortunately, most of these studies look at l-theanine+caffeine vs placebo. They do not compare l-theanine+caffeine vs caffeine alone. So basically you can't tell with these studies if the effect is coming from the caffeine or if l-theanine is having some contribution. (we already know that caffeine is a nootropic, so these results are not impressive) The ones that do this comparison don't have the most impressive results for l-theanine. Overall, I was fairly unimpressed by the quality of evidence for the efficacy of l-theanine.
I did find a recent meta-analysis on l-theanine/caffeine. (http://www.ncbi.nlm.nih.gov/pubmed/24946991). It was not very well written unfortunately. I read the full article (the abstract is fairly misleading I found) and once again, they did not do a good job, I don't think, in trying to assess whether l-theanine was synergestic with caffeine, for the most part they looked at the two in combination without really doing a go…
What they were answering
AoE-Priest · 6 points
Both interesting studies. The first one actually also showed some anti-nootropic effects of theanine as well, but overall both studies seem to be suggestive of at least minor synergy between caffeine and l-theanine. Statsitically significant, but if you look at the effect sizes, I don't know if it's something you would notice. The other thing that bothers me is that the effects that ARE positive, are not consistently positive between studies. Overall, it seems like there still needs to be a lot of work done.
u/MisterYouAreSoDumb · Ceretropic
L-theanine is certainly anti-nootropic for me, unless I am using much stronger stimulants than caffeine. Everyone's GABAergic system is going to vary. Mine has seen some things. I can take all sorts of stimulants, and be perfectly fine. Other people would get anxious on the amounts that I can handle. For them, L-Theanine provides a synergistic effect with Caffeine. For me, I get tired and cranky. However, it's hard to ignore all the positive reports from people.