One particularly interesting nootropic for the over caffeinated crowd is l-theanine. This is a smart drug that naturally occurs in teas and some mushrooms. In Japan l-theanine is added to commercial teas, soft drinks and desserts. This substance is generally recognized as safe (GRAS) by the FDA and is available in the US through the supplement market.

Applications:

• Mental Alertness (Increased Alpha Brain Waves) – L-theanine, a natural constituent in tea, and its effect on mental state and The deployment of intersensory selective attention: a high-density electrical mapping study of the effects of theanine.
• Combine with Caffeine for reduced susceptibility to distractions – The combined effects of L-theanine and caffeine on cognitive performance and mood and jitter management.
• Calming –L-Theanine reduces psychological and physiological stress responses.
• Sleep – The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial.
• Memory – A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study.

Usage:

50mg – 250mg is the normal dosage range. Reports of stomach irritation occur at dosages over 400mg. L-theanine is water-soluble. I normally dissolve 100mg powdered l-theanine in water and take up to four times daily.

Sources:

https://examine.com/supplements/Theanine/

http://www.ncbi.nlm.nih.gov/pubmed/16373462

http://espace.library.uq.edu.au/view/UQ:284103

http://www.ncbi.nlm.nih.gov/pubmed/16930802

http://www.ncbi.nlm.nih.gov/pubmed/17272967

http://www.ncbi.nlm.nih.gov/pubmed/23458739

http://www.ncbi.nlm.nih.gov/pubmed/18681988

http://www.ncbi.nlm.nih.gov/pubmed/21303262

http://www.ncbi.nlm.nih.gov/pubmed/22214254

http://www.ncbi.nlm.nih.gov/pubmed/22819553

http://www.ncbi.nlm.nih.gov/pubmed/18006208