Getting "Tea Drunk" is a common pursuit for many fine tea drinkers, myself included. My partner and I enjoy cultivars that give you a buzz. I went down a rabbit hole in trying different varieties and we found some that can only be drunk at the end of the day after work, else you'd write off the rest of the day. We had an aged white tea once that made us giggle like we were on shrooms, without all the overwhelming side effects or fear of a "bad trip".

I started watching "Mei Leaf", who's a YouTuber with a deep knowledge of tea and gong fu style brewing specifically and was hooked. He's got a video on getting tea drunk specifically that made me hunt the feeling initially: https://www.youtube.com/watch?v=HrLaKX9J8Uo

Adding my own experience, I take 200MG L-Theanine supplements daily and there is a noticeable calmness. It used in combination with Caffeine a lot to soothe the jitters. There isn't a known LD50 and I've taken up to 600MG, at best I can say it's borderline euphoric. Nowhere comparable to LSD even at the 20MCG level