noun
weight-loss drug; diet pill; slimming medicine
Refers to any medication or supplement intended to promote weight loss. Can be used for prescription drugs, over-the-counter pills, or herbal remedies.
彼女は痩せ薬を飲んでダイエットしている。
She is dieting by taking weight-loss pills.
その痩せ薬は副作用が強いらしい。
That diet drug seems to have strong side effects.
Refers to dieting in general, not specifically to medication.
Dietary supplements; broader category that may include weight-loss aids but also vitamins and minerals.
Compound of 痩せ (yase, 'losing weight') + 薬 (kusuri, 'medicine').