L-theanine is an amino acid that is naturally found in green tea. You can also find it in the form of supplements. According to amazing-green-tea.com, the FDA declared L-theanine in 2007 as a generally safe product.
According to emedtv.com, L-theanine is used for the treatment of Alzheimer’s disease, hypertension and anxiety.
Emedtv.com states that there are no reported side effects of L-theanine. However, this does not necessarily mean that L-theanine will not cause side effects. If you start to feel different in any way, call your doctor.
Studies conducted on L-theanine usage in rats have revealed an increase in kidney tumors, according to emedtv.com. However, it is believed that L-theanine may not be the cause.
According to emedtv.com, you should not take L-theanine if you have kidney or liver disease, severe allergies, or a chronic health condition. Also, the effects of L-theanine on pregnant or nursing women are unknown, so it is best to avoid it all together.
According to amazing-green-tea.com, taking too much L-theanine can lead to a feeling of over-relaxation, which may affect manual work. The website suggests that you take no more than 400 milligrams a day.