Theanine is similar to glutamate, a naturally occurring amino acid. Glutamate helps transmit nerve impulses in the brain. Theanine sometimes acts like glutamate in the body. But other times it seems to block the effects of glutamate. Theanine might also affect the brain chemicals GABA, dopamine, and serotonin.
People use L-theanine to improve mental function. It is also used for anxiety, mental impairment, stress, and other conditions, but there is no good scientific evidence to support these uses.
Don't confuse theanine with another amino acid called threonine. These are not the same.
Uses & Effectiveness
Possibly Effective for
Special Precautions and Warnings
Children: L-theanine is possibly safe when taken by mouth, short-term. Doses of 400 mg daily have been safely used for up to 6 weeks in males aged 8-12 years.
Medications for high blood pressure (Antihypertensive drugs) interacts with THEANINE
Theanine might lower blood pressure. Taking theanine along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.
Be cautious with this combination
Sedative medications (CNS depressants) interacts with THEANINE
Some medications, called sedatives, can cause sleepiness and slowed breathing. There is some concern that theanine might also cause sleepiness and slowed breathing. But most research hasn't shown this effect. For now, use theanine with caution if you are taking sedative medications.
Be watchful with this combination
CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.
This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2018.