A patient asked:
A question: Green tea and mate do well for me. However, on a day I don’t drink either, by noon or a bit later I get a headache and a groggy feeling. Do you have an “eitzah?”[advise]

Thank you for your question.
you may be very sensitive to [the “bit” of] caffeine that these teas contain [especially mate] and therefore get much easier than other people’s “withdrawal” headache.
[I have it with even one cup of coffee a day[if I skip], but I also seem to belong-like you- to the rare “animals” because most people would not have this withdrawal phenomenon with one cup]
So, if it does you well don’t worry, just drink your “cups” [Mate means cup] and try before a major fast day to gradually reduce it, in order to prevent a “bad fast”.
kol tuv

A few words about Mate [Yerba mate, Ilex paraguariensis]:
Mate tea is widely used in South America as a national drink, in the way the Japanese hold a tea ceremony.
Many medical properties have been connected with it and for sure it is a stimulant, like coffee.
It contains quite a bit of vitamins, minerals and even some 15 amino acids [parts of proteins]!!
Although it can be overstimulating some herbalists claim that it does not have the side effects of coffee.[palpitations,anxiety,jitteriness,insomnia]
It probably all comes down to how every individual is metabolizing this tea [like I wrote in the past about coffee]