inyakuhin

Inyakuhin (Japanese: 医薬品) is the Japanese term for pharmaceutical products, encompassing any substances or preparations intended for medical use such as drugs, contraceptives, and certain health supplements. The word is composed of two kanji: 医 (medicine, medical) and 薬品 (drug, pharmaceutical substance). Inyakuhin are governed by Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) and the Ministry of Health, Labour and Welfare (MHLW). Under Japanese law, medical substances are classified into prescription medicines, nonprescription medicines, and medical devices, with each category subjected to different regulatory approval processes.

Prescription medicines, known as 認定薬 (nintei-yaku), require a prescription from a licensed medical practitioner and must satisfy stringent preclinical and clinical safety and efficacy studies before approval. Nonprescription medicines, or 安否薬 (anpi-yaku), may be sold over the counter and have a lower threshold for clinical evidence, though they are still subject to quality, safety, and efficacy standards. Historically, the 1993 Drug Reform Act brought significant changes, aligning Japan’s pharmaceutical regulations more closely with international standards, including the establishment of the PMDA in 2004 as an independent regulatory body.

Inyakuhin also includes certain dietary supplements that are marketed with health claims, regulated under the Food Sanitation Act rather than the Pharmaceutical Affairs Act. However, any product purporting to treat or cure disease is strictly considered an inyakuhin and must be licensed accordingly. The regulatory framework ensures that all inyakuhin available in Japan meet consistent safety, quality and efficacy standards, thereby protecting public health.