L-Theanine

OTHER NAMES: L-Theanine

HISTORY: L-theanine is an amino acid extracted from black and green tea, discovered in 1949. Since that time, it has also been made synthetically as a supplement. a 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: May help reduce high blood pressure

Respiratory: Flu, cold symptoms

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

Mental Health: Questionable: Tics, anxiety, stress, 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: 

RECOMMENDED BRANDSGreen or black teas (especially matcha), capsules, tablets, powder, chewable

• Life Extension® Theanine XR™ Stress Relief - Order on Life Extension link here)

• Doctor's Best® L-Theanine with Suntheanine - 

• Fit Powders L-Theanine 

• GNC L-Theanine - 

• Healthy Origins® L-Theanine

• Nature's Trove® L-Theanine 200 mg 

• Solgar® L-Theanine 150 mg 

• Thorne Theanine capsules 200 mg - NSF Certified - Order through the Fullscript link here

• New Medica L-Theanine 200 mg capsules- NSF certified - Order through Fullscript link here

• Nature's Way L-Theanine 200 mg capsules - NSF Certified - Order through Fullscript link here

Note: I only recommend herbal and supplement brands that meet high standards for safety, effectiveness, and transparency. I research each product before sharing. Some links—like those to Amazon—are affiliate links, meaning I may earn a small commission if you buy through them, at no extra cost to you. It helps support this free site. Plus, these links often offer discounts, fast shipping, and helpful reviews.

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)

Disclaimer: The material above is for informational purposes only. This information is not intended to diagnose or treat a condition. The uses listed above are tentative; some have or are undergoing research trials, but many are not FDA-approved. It is essential that you investigate these supplements further before deciding to use them. Check interactions and contraindications on sites like Drugs.com or WebMD. Do not attempt to treat a serious condition like liver, kidney problems, high blood pressure, heart disease, cancer, diabetes, or thyroid issues without discussing it with a healthcare provider first. If you are pregnant, do not use supplements without discussing it with your healthcare provider.