A little bit off topic, but your remark reminds me of a regrettable story early '00 in Japan where the anti-obesity API fenfluramine (prohibited in 1977 in US due to adverse reaction linked to cardiac abnormalities) was mimicked in a Chinese dietary supplement for weight loss by adding around 3% N-nitroso-fenfluramine. However, NFEN doesn’t inhibit appetite, but might induce hepatopathy including biliary congestion and nephropathy. Different users died (estimated daily intake 0.52 mg/kg bw) due to severe liver suffering (possibly linked with CYP2C19 poor metabolizer phenotype).
N-ニトロソ-フェンフルラミンの検出等について (mhlw.go.jp)
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