L-Theanine is used in an array of supplements. One of its best attributes is that it may promote relaxation without causing any drowsiness. You will find L-Theanine in anything from pre-workouts to sleep aids to nootropics. 

Due to L-Theanine not being a sedative, it is more of an add-on for a sleep aid as opposed to the powerhouse of a sleep aid. It actually makes a good addition to GABA as shown in this study for the purpose of increasing REM sleep.

As for pre-workouts, a study shows that it has been shown to work synergistically with caffeine. So adding it to a pre-workout may be beneficial. Many companies throw it in pre-workouts to prevent jitters or the stimulant crashes that commonly happen with stim-based pre-workouts.

Nootropic supplements also like to combine caffeine with L-Theanine to promote a calming, relaxation impact which clears the brain and allows the user to focus.

As stated above, L-Theanine should be stacked with either caffeine or with other sleep aid supplements such as GABA, depending on your goal.

If you're looking at a nootropic, L-Theanine should be combined with caffeine and cognitive ingredients like Alpha-GPC and/or Huperzine A.

It may lower blood pressure, however it is not common. L-Theanine is actually very safe and is one of many supplements that may actually be recommended for children (ages 8-12) for relaxation purposes.

Doses of up to 400mg have been shown to be safe. We suggest starting around 50mg-100mg and working your way up from there.

The following products contain L-Theanine at the recommended dosage, and are recommended supplements for Fitness Informant: