L-theanine is an amino acid found naturally in tea leaves that some people take as a supplement to support relaxation and focus. Unlike caffeine, which can make you feel jittery, L-theanine is thought to promote a calm, alert state—the reason many people drink tea to unwind. You might land here wondering whether L-theanine could help with stress, sleep, or concentration, or straightforward wanting to understand what it is and how it works in your body.
The articles here explore what L-theanine actually does, how it compares to other supplements and beverages, what research shows about its effects, and what you might want to know before trying it. You'll find information about typical doses, how long it takes to feel effects, and whether it interacts with medications or other substances you might be using.