Doctor's Best Suntheanine L-Theanine

90 vcaps
Doctor's Best L-Theanine with Suntheanine

Suntheanine is the patented formula of L-theanine in its purest and most effective form, manufactured in Japan from Green tea leaves. L-theanine is a non-essential amino acid that produces anti-stress, mood regulating, immune stimulating, and skin care benefits. Doctor’s Best Suntheanine contains 100% pure Suntheanine for relaxation, positive mood, and mental alertness.

Supplement Facts

Serving Size: 1 Capsule
Servings Per Container: 90


Amount Per Serving

% Daily Value

L-Theanine (with Suntheanine®)

150 mg


† Daily Value not established.

Other Ingredients: Microcrystalline cellulose, modified cellulose (vegetarian capsule).

Suggested Use

Adults only. Take 1 capsule daily, away from food, or as directed by a health care practitioner.


L-theanine has been historically used for its anti-stress effects without feeling drowsy and while remaining mentally alert. L-theanine supplements produces calming effects to help people who live a very active and fast-paced lifestyle to get periods of relaxation. By promoting adequate relaxation periods, Suntheanine allows for rejuvenation of the major organs like the heart and brain. It also supports longevity by counteracting the debilitative effects of stress to the immune and nervous systems. L-theanine capsules promote total mental health by regulating mood and promoting a healthier disposition. This amino acid does all these anti-stress mechanism without producing drowsiness, like some other anti-stress formulations. L-theanine supplements also regulate normal blood pressure levels as it acts on chemicals involved in blood pressure control. According to experts, L-theanine also possesses mild antioxidant activities that reduce oxidative stress to cells, especially to serum lipids. Oxidative stress to lipids leads to its rancidity, causing them to form plaques that attaches to blood vessel walls, a condition called atherosclerosis. For skin care, L-theanine is being used as an active ingredient in night creams that ensures to moisturise and rejuvenate the stressed out portions of the dermis.

L-Theanine is a non-essential amino acid that is exclusively found in the leaves of the green tea plant. It is also one of green tea’s health promoting substances. This non-protein amino acid is naturally synthesised in the roots of the camellia sinensis (green tea) plant and then transported to its leaves. L-theanine comprises of approximately 2% of the total dry weight of green tea leaves. Green tea over the centuries produces its signature taste and its remarkable relaxing effects, known to countries like Japan and China. According to research, L-theanine is responsible for this green tea benefits. Studies also show that an L-theanine supplement has the ability to cross the blood-brain barrier within 30-40 minutes after ingestion so it can produce direct effects to the brain. Within the brain, L-theanine works by producing two mechanisms. First by stimulating the production of alpha waves that creates calming and relaxing effects, as well as mental alertness. Second by acting as a precursor to the neurotransmitter GABA (Gamma Amino Butyric Acid), that acts on two other neurotransmitters, Domapine and Serotonin for stronger relaxation effects. Doctor’s Best Suntheanine uses the purest and most effective form of L-theanine. It is manufactured from natural green tea leaves in Japan to produce natural and maximum L-theanine benefits to the body.