medical efficacy; effect of a medicine
Refers to the therapeutic effectiveness of a drug or medicine. Common in medical, pharmaceutical, and health-related contexts.
この薬の薬効は臨床試験で証明されている。
The medical efficacy of this drug has been proven in clinical trials.
薬効が切れると、また痛みが戻ってきた。
When the effect of the medicine wore off, the pain returned.
medically effective ingredient
Compound of 薬 (medicine) and 効 (effect). The reading やっこう is a regular on'yomi combination.