Me going down a caffeine rabbit-hole? Never.
It is though very interesting kinda.
The US are wild on caffeine like wtf?
Matcha has quite some caffeine to it though L-Theanin seems to work slightly different.
Coke funnily does not have too much: 10mg/100ml
Germany regulates this for up to 25mg/100ml max. So stuff like Afri or Fritz-kola have that.
Energies can have up to 32mg/100ml caffeine, but 400mg/100ml Taurin are fine as well.
Regulated in the delightfully named "Fruchtsaft- und Erfrischungsgetränkeverordnung" or FrSaftErfrischGetrV for short
You can sell stuff with more than 32mg/100ml but then its not a drink but a supplement.
From what I can find 400mg per day are safe for an adult. Upto 200mg are fine in single serving
Tea and coffee have more than the energy.
Matcha has quite some of it as well. A gram of matcha has about 35mg per gram of powder (seemingly)
some more:
Coke: 10mg/100ml
Afri-kola / Fritz-Kola: 25mg/100ml
Monster-Energy usually: 32mg/100ml
dmBio-Mate: 30mg/100ml
Club-Mate: 20mg/100ml
normal filtered coffee 80mg/100ml
a whole can of monster has 160mg caffeine btw. America has some varients with a little more in a can.
Thank you for coming to my caffeine TED-Talk