A large share of herbal supplements are secretly adulterated with undisclosed pharmaceuticals

Evidence

Furthermore, an analysis of 2,609 herbal samples found that 23.7 percent—almost one in four—were adulterated with pharmaceuticals. A parallel California study found that 7 percent contained undeclared pharmaceuticals.29 — Harriet A. Washington, A Terrible Thing to Waste, 1147

Categorization

• corroborated: 2 independent passages support this claim — Harriet A. Washington, A Terrible Thing to Waste, 1147
• recurring: this claim recurs 2 times within its source
• XREF: connects to: Patent medicines relied on mysterious secret ingredients to feed consumer hope — Tim Wu, The Attention Merchants, 97