L-Theanine is an amino acid found in tea leaves. This compound promotes calm relaxation without drowsiness and helps manage everyday stress. When taken with caffeine, it improves concentration.
People take L-Theanine to cut stress, sharpen focus (especially with caffeine), and relax before bed. Some users find it helps them sleep, but the evidence is modest. It is not a direct sleep aid. Instead, it may quiet a racing mind.
Typical doses range from 100 to 400 mg, taken with or without food. Take it alone for relaxation or with caffeine for a focused, alert state. Side effects may include mild headache or dizziness. L-Theanine might increase the sedative effects of CNS depressants like alcohol or benzodiazepines. If you are pregnant or nursing, talk to a doctor before using it.