bL-Theanine Powder Overview/bbr L-theanine powder is a popular dietary supplement ingredient which promotes mood, relaxation, and cognition. Theanine makes for an ideal combination with caffeine supplements or coffee. The optimal ratio of L-theanine to caffeine is 2:1 or 1:1 depending on the individual.brbr bQuality/bbr This L-theanine is third-party tested in a US lab for guaranteed purity and potency. Freshness guaranteed 2 years from purchase date. brbr bL-Theanine Dosage/bbr Take either 100 mg or 200 mg as needed. Do not exceed 400 mg daily. The included scoop measures roughly 200 mg.