Too effective 〜すぎる
The relaxing effect of the herbal tea Cocoa drank was too effective, as she fell right to sleep. (Note that 効く is a verb, not an adjective, meaning “to be effective” or “to do its work”.)
The relaxing effect of the herbal tea Cocoa drank was too effective, as she fell right to sleep. (Note that 効く is a verb, not an adjective, meaning “to be effective” or “to do its work”.)