副作用

• Reading: ふくさよう
• Romaji: fukusayou
• Kanji breakdown: 副 (fuku) — secondary, vice-; 作 (sa/saku) — make, action; 用 (you) — use, effect
• Pronunciation: /ɸɯ.kɯ.sa.joː/

Meaning

Side effect; adverse reaction. An unintended effect caused by medication or treatment.

A noun describing unwanted effects from medicine or medical treatment. Commonly used in phrases like 副作用が出る (side effects appear) and 副作用がある (there are side effects). Frequently encountered on medicine packaging, in doctor consultations, and in health news.

Examples

1. この薬には眠くなる副作用がある。 This medicine has a side effect of making you drowsy.
2. 新しい薬の副作用が心配だ。 I'm worried about the side effects of the new medicine.
3. 副作用が出たらすぐに医師に相談してください。 If you experience any side effects, consult your doctor right away.

Usage Guide

Context: health, pharmacies, medical consultations

Tone: neutral

Origin & History

Compound of 副 (fuku, secondary/sub-) and 作用 (sayou, action/effect). Literally 'secondary effect,' describing an effect beyond the intended one.

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal