L-theanine is a natural supplement that slows brain waves to improve relaxation and sleep quality. Absorption takes about 30-60 minutes, and it stays in your system for about five hours. Take ...

Daniel Combs, MD, is an Assistant Professor of Pediatrics and Medicine at the University of Arizona. Melatonin may improve sleep quality better than L-theanine, and there is stronger research evidence ...

If your household runs on long days and short nights, you’ve probably wondered whether there’s something gentler than a conventional sleep aid for those nights when a busy mind just won’t quit.

L-theanine is an amino acid naturally found in tea leaves. First linked to tea’s calming effects in the 1940s, it is now sold as a supplement for stress relief, focus and better sleep. Research into ...

Two 2025 studies just made the strongest case yet for L-theanine as a natural sleep aid. AFP via Getty Images A lot of people are quietly rethinking their relationship with melatonin right now. A ...

Emmanuella Ogbonna is a licensed pharmacist, health writer, and medical researcher. L-theanine is a natural supplement that slows brain waves to improve relaxation and sleep quality. Absorption takes ...

L-theanine is a compound commonly found in tea leaves, including green, black, white, and oolong teas. The best time to take L-theanine depends on your reason for use. Ideally, take it just before you ...