Uses & Effectiveness

Overview

Theanine is an amino acid found in tea and some mushrooms. It comes in two forms: L-theanine and D-theanine. L-theanine is the most common form.

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.

Theanine is an amino acid found in green tea that stimulates the production of alpha brain waves, inducing a calm and relaxed mental state while enhancing focus and alertness, making it a popular ingredient in natural stress-relief supplements.

Side Effects

When taken by mouth: L-theanine is possibly safe when used short-term. Doses of up to 900 mg daily have been safely used for 8 weeks. It isn’t clear if L-theanine is safe to use for longer periods of time. It might cause mild side effects, such as headache or sleepiness.

Interactions

Moderate Interaction

Be cautious with this combination

• 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.

Minor Interaction

Be watchful 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.

Special Precautions and Warnings

Pregnancy and breast-feeding: There isn’t enough reliable information to know if theanine is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

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.