it sounds like it only helped the headache so much, because it was caused in the first place by the withdrawal of the caffeine.. so it's not a headache cure, but replacing the drug that was being withdrawn from.
would that not have been caffeine withdrawal though ? If you'continued with the de-caf, those symptoms should've gone in time, like any drug you're gonna notice when you stop taking it.
(do skréše) Jak chceš vlitnót do špilo se špilošem, keré bode asi tak dobré jak te, možeš zvolet vežadované rozsah BKR v novy nabidce ke špilo. Potem nikdo, kdo do rozsaho nepasoje, toďto nabidko ani neovidi. (Katechka) (okázat šecke vechetávke)