Ren Zhong Bai

Ren Zhong Bai is not a plant. It is the mineral deposit scraped from the inner walls of long-used chamber pots and urinals, so the starting material is pooled, anonymous human urine from donors who cannot be identified. Urine is not sterile and is a recognised shedding route for Mycobacterium tuberculosis in renal tuberculosis, for Schistosoma haematobium ova in urinary schistosomiasis, for cytomegalovirus and the BK and JC polyomaviruses, for Leptospira, and for the ordinary urinary pathogens Escherichia coli, Klebsiella and Proteus. The presence of struvite in the deposit is itself proof that urease-producing bacteria acted on the source urine. Any haematuria in a donor, which is common and often unnoticed, introduces blood and with it the risk of HIV, hepatitis B and hepatitis C. A prion risk is theoretical rather than demonstrated for urine, but prions are not inactivated by the temperatures and times used in ordinary autoclaving, let alone by traditional processing. Traditional processing is soaking in changed water for four to seven days, then fifteen days of sun and night dew, or calcination in a covered clay jar in charcoal ash until red through. Red-heat calcination would destroy organic pathogens, but it is neither validated, monitored nor uniformly applied across trade material, and no processing method for this drug has been shown to inactivate the agents above.

Ren Zhong Bai is not included in the current Chinese Pharmacopoeia, so there is no official monograph, no identity test, no purity limit and no assay for it; whatever a supplier ships is what the patient gets. The direction of travel for human-derived materia medica in that pharmacopoeia is away from inclusion: Placenta Hominis, Zi He Che, was still an official drug with a monograph in the 2010 edition and was not carried forward into the 2015 edition, on safety and ethical grounds. Outside China, human-derived substances are generally regulated as human tissue or as biologicals rather than as herbal medicines. In Australia they fall under the biologicals framework of the Therapeutic Goods Act, so they cannot be supplied as listed complementary medicines and it is an offence to manufacture therapeutic products from them without the appropriate licence, and human body fluids and tissues are listed in Schedule 6 of the Customs (Prohibited Exports) Regulations 1958 and need a permit to export. The European Union, the United States and Canada likewise handle human-derived material through tissue and biologics regimes rather than through their traditional-herbal-medicine pathways. A practitioner importing, holding or dispensing this material is therefore likely to be outside the law in several jurisdictions regardless of clinical intent.