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Are L-Theanine and Caffeine Synergistic?



## Edit 2013-10-21## – We have been informed that Natural Stacks have developed a caffeine plus theanine formula. Each capsule contains 100mg caffeine and a generous 200mg theanine.  Check the product out here – your purchase supports Smarter Nootropics

I’ve noticed recently there has been a lot of interest on’s /r/nootropics board and Longecity’s nootropics forum about the combination of L-Theanine and Caffeine. L-Theanine has been considered a nootropic for awhile, and Caffeine is pretty much the nootropic that most people use in their daily life. After seeing a number of posts on the topic of combining L-Theanine with Caffeine, I decided to investigate whether or not there are actual synergistic effects.

Research shows that there were a few clinical trials in which volunteers were administered either a placebo or L-Theanine and Caffeine. The amounts in different trials were different, but they were all in the 100-200mg range for L-Theanine and the 50-100mg range for Caffeine. Test subjects were then given different tasks to perform and their performance was measured at multiple points throughout the tests.

In one test administered at the Nathan S Kline Institute for Psychiatric Research, the test subjects also had electrodes placed on their scalp and were measured for brainwave activity, with a specific emphasis on tracking alpha-band activity.

The test subjects were measured for two performance criteria, Hit Rate and Discriminability. The test subjects on a combination of L-Theanine and Caffeine showed an increase in both Hit Rate and Discriminability over placebo. The test subjects showed an increase in Hit Rate but not Discriminability when administered Caffeine only. They showed no effects vs placebo for L-Theanine alone.

This is one example of a study which showed a positive synergistic correlation with Caffeine and L-Theanine combined. There are others which I will link at the bottom of this page.

After reading this, I performed my own test with L-Theanine and Caffeine. I took the two at the same time and noticed after about 15 minutes a definite increase in alertness. During the following couple of hours, I finished a number of tasks quickly and accurately. I had higher focus than I typically do with Caffeine alone. One of the tasks I completed while taking the combination of L-Theanine and Caffeine was writing the L-Theanine article for this website.

I will state that L-Theanine and Caffeine subjectively seems to cut down on some of the less pleasant side-effects of Caffeine itself. There was less twitchiness and nervous energy than usual. It felt very clean and I was able to stay focused on work longer than usual with fewer breaks.

In conclusion, both the research supports a synergistic effect when L-Theanine and Caffeine are taken together. In my own personal experimentation I have found that subjectively it feels cleaner than either taken alone, and is definitely a nootropic combination worth pursuing.

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  1. Susan   •  

    There is a new enhanced water that has just natural caffeine and theanine in it called Element Caffeinated Water ( and they also have clinical studies on their website that show conclusions of clinical studies of caffeine and theanine together.

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