Theanine is an amino acid found naturally in the green tea plant (camellia sinensis). Theanine is a popular ingredient in pre-workout and nootropic products, particularly in combination with caffeine. Each capsule from Swanson Health is packed with 200mg of L-theanine in the premium form; Suntheanine® and is an easy way to increase the amount of L-theanine in the diet. Suitable for vegetarians. Theanine is an amino acid found naturally in the tea plant (camellia sinensis). Theanine is a popular ingredient in pre-workout and nootropic products, particularly in combination with caffeine. Each capsule from Swanson Health is packed with 200mg of L-theanine in the premium form; Suntheanine® and is an easy way to increase the amount of L-theanine in the diet. Suitable for vegetarians. Amino acid found in the green tea plant. 200mg of L-theanine per capsule. Premium form of L-theanine; Suntheanine®. Suitable for vegetarians. 60 capsules per pack Double Suntheanine, from Swanson Health, provides 200mg of L Theanine per capsule. Suitable for vegetarians.