Beeing curious, I ordered regular and premium red veins leafs from a reputed website, you know which one.
I made tea with lemon juice, 20 min infusion at 5, 7.5 and 10g with both batches (so 6 tries)
Got some very mild stimulation and numb tongue with the higher dosages, and slight anestesia of the face for like 10 min.
highest dosages gave me a slight drowsy feeling, and a sensible stomach/medium nausea which lasted for a while. (Nothing too bad, but not really great either)
"Pleasurable" feelings for all tries were not greater than those of a single beer or 1-2 marijuana tokes, and were overshadowed by the nausea.
I took opiates twice in my life before that.
At 3-10$ per brew (5g normal vs 10g premium leaf), I won't buy again, and will throw away what is left.