supplementary action; adjunctive effect
Pharmacology term for an auxiliary or supportive action of a drug or treatment, often used in medical contexts.
As a supplementary action of this drug, an anti-inflammatory effect is expected.
主作用 refers to the primary or main action of a drug, while 補助作用 is a secondary, supportive effect.
Compound of 補助 (hojo, 'assistance, support') and 作用 (sayō, 'action, effect'). The exact historical derivation is uncertain, but the term is used in modern pharmacology.