L-Theanine is an analog of the non-essential amino acid, glutamate. This particular amino acid is naturally found in (Camellia sinensis) or what is more commonly known as the tea plant. It is credited as the main natural ingredient that gives green tea its soothing quality. It may also be found in mushrooms specifically in bay boletes (Boletus badius).
Widely known for its relaxing effect, L-Theanine is made available in supplements and as an ingredient in beverages other than green tea, to ease anxiety and enhance mood. An article in the LA Times at http://articles.latimes.com/2009/may/04/health/he-theanine4 points out that though many drinks are marketed for their energy boosting properties, there are times when that boost is not exactly what people need. In fact, Dr. Michael Breus of the Huffington post at http://www.huffingtonpost.com/dr-michael-j-breus/energy-drinks-health_b_1496915.html outlines some of the side effects of these energy drinks including anxiety, restlessness, heart palpitations and insomnia.
Sometimes people just want the ability to focus, a bit of calm and a good night’s sleep. This is where L-Theanine proves to be highly valuable. A frequently cited study of Lyon MR, Kapoor MP and Juneja LR found that young boys with Attention Deficit Hyperactivity Disorder (ADHD) who took L-Theanine had better sleep than the group of boys who did not.
There are many studies that explore L-Theanine’s benefits apart from stress and anxiety relief. Researchers are finding promising results of L-Theanine’s effectiveness in reducing weight, preventing stroke and helping in cancer treatments.
No conclusive evidence has shown L-Theanine’s negative side effects but it is recommended that pregnant and breastfeeding mothers refrain from its use. For tablets, there are also recommended doses depending on age, weight and other health conditions. It is always best to consult a doctor when planning to take a new supplement. Otherwise, it is believed to be safe.