Table 5.

Potential Harmful Substances Related to COVID-19.

Supplement	Mechanism of action and potential benefits	Potential harms or adverse reactions	Ongoing registered clinical trials related to COVID-19
Elderberry (Sambucus)	Antiviral activity, especially in context of influenza pneumonia	May increase TNFa and IL-6 levels, exacerbating cytokine storm contributing to ARDS in COVID-19	There are zero registered clinical trials related to elderberry and COVID19 on clinicaltrials.gov
Colloidal silver	Antibacterial and potentially antiviral properties when administered topically	May cause peripheral neuropathy or argyria with oral high doses	There is 1 registered clinical trial related to colloidal silver and COVID19 on clinicaltrials.gov
Licorice (Glycyrrhiza glabra)	Herbal medicine with purported benefits for cough or febrile illness	May cause pseudoaldosteronism with hypertension and possibly death	There are 2 registered clinical trial related to licorice and COVID19 on clinicaltrials.gov
Oleander (Nerium oleander)	Herbal medicine with unclear medicinal value	Cardiac glycoside action may cause arrhythmias and possibly sudden cardiac death	There is 1 registered clinical trial related to oleander and COVID19 on clinicaltrials.gov