L-Theanine

OTHER NAMES: Theanine

HISTORY: L-theanine is an amino acid extracted from found in black and green tea discovered in 1949. Since that time, it has also been made synthetically as a supplement. Few studies back up the actions of L-theanine (below). It is thought to exert its action by boosting various neurotransmitters: GABA, serotonin, and dopamine.

CONSIDERED USES

Cardiovascular: High blood pressure

Respiratory: Flu, cold symptoms

Neurologic: Mental performance, ADHD (especially if taken with moderate caffeine), Alzheimer’s, cognitive decline/impairment (age-related), cognitive function, insomnia, Tourette’s

Mental Health: Tics, anxiety, depression, OCD, schizophrenia, stress

Cancer: Possibly helps

Side Effects: Low blood pressure, decreased appetite, digestive problems, headache, moodiness, problems concentrating, dizziness, jitteriness

Cautions/Contraindications: Possible interactions with some blood pressure medicines and benzodiazepines (Ativan, Xanax, and others) and sedating medications might also decrease the effects of stimulants

FORMS: Teas (especially matcha), capsules, tablets, powder, chewable

DOSAGES: As directed

The following are reported doses and may NOT be supported by evidence (reported by various sources, i.e., WebMD, RxList, Epocrates, ConsumerLabs, German Commission E). Read dosages and instructions carefully when available on the label.

• General: 200-400 mg by mouth daily for 4 to 8 weeks (up to 500 mg)

• Anxiety: 200 mg by mouth once daily

• Attention: 100-400 mg by mouth daily

• Cognitive function: 100-200 mg by mouth once daily

• Depression: 250 mg by mouth at bedtime

• Insomnia: 50 mg by mouth at bedtime (take one hour before bed)

• Stress: 200 mg by mouth 1-2 times daily

• Mental Acuity: 100 mg by mouth before a test (with caffeine)