The next morning, I had a bagel and one daily tea, as instructed. I felt my stomach become uneasy as most stomachs do when they’re working their “digestive magic.” Suddenly, the worst cramp of my life hit me out of nowhere. It was the sharpest PANG I’ve ever felt as it made its way from my stomach to my chest. As a reflex, I jumped up. That’s when I felt another wave of pain and swiftly made my way to the restroom.
Matcha typically has more caffeine content than green tea, similar caffeine to black tea, and less caffeine than brewed coffee. Because matcha is produced from shade-grown tea bushes, the tea leaves tend to retain more of their caffeine content. In addition, since you’re consuming the ground tea leaf when sipping matcha, you’re ingesting more caffeine content than you would from the extraction of steeped green or black tea leaves. Like all drinks cultivated from caffeinated plants, however, a specific level of caffeine per cup of matcha tea will depend on the how the matcha was processed and prepared. Be sure and read the packaging carefully or ask your tea supplier directly for the caffeine information specific to the matcha you are buying.
Day 3: As I started to make my 5th cup in 3 days, my best friend said, “Ab, I really don’t think you should be drinking so much of this stuff. Why don’t you just stick to the recommended amount?” I responded with “It’s just TEA — what’s the worst that could happen?” On day 3, I learned. I had decided to give up coffee during my 28 days, both as a way to save my sanity and excretory system and as a way to wean myself out of my coffee habit. That was really stupid. By day 3, I was experiencing a horrifying caffeine headache and a rough case of the spins. I was also literally exhausted and finally feeling the ~desired effects~ of the detox (frequent trips to the bathroom, to put it lightly), so I was dealing with an excess of that on top of my other horrible side effects. Do I blame the tea? Not even a little. I blame myself for overindulging in too much of a good thing. From there on out, I decided to follow the rules.
^ Jump up to: a b Onakpoya, I; Spencer, E; Heneghan, C; Thompson, M (August 2014). "The effect of green tea on blood pressure and lipid profile: a systematic review and meta-analysis of randomized clinical trials". Nutrition, Metabolism, and Cardiovascular Disease (Systematic Review & Meta-Analysis). 24 (8): 823–36. doi:10.1016/j.numecd.2014.01.016. PMID 24675010.

Grown under shade for three weeks prior to plucking, gyokuro is one of the most exclusive varieties of tea produced in Japan.[60] The shading technique imparts a sweeter flavor, and produces a particularly rich color thanks to the higher amounts of chlorophyll in the shaded leaf. Gyokuro tea is associated with the Uji region, the first tea-growing region in Japan. It is often made using smaller-leaf cultivars of the tea plant.[61]