stimulant effect; wakefulness-promoting action
Refers to the property of a substance (such as caffeine) that promotes alertness or counteracts drowsiness. Often used in medical, pharmacological, or everyday contexts.
Thanks to the stimulant effect of coffee, I was able to study late into the night.
This medicine has a strong wakefulness-promoting effect, so please avoid taking it before bedtime.
覚醒 means 'awakening' or 'arousal' in a broad sense, while 覚醒作用 specifically refers to the stimulant or wakefulness-promoting effect of a substance.
作用 means 'action' or 'effect' in general; 覚醒作用 narrows it to the specific type of effect.
Compound of 覚醒 (かくせい, 'awakening') and 作用 (さよう, 'action, effect'). The term is straightforward and modern, with no obscure historical derivation.