Background:
Natural products are commonly used for treating health problems. These products may be
associated with adverse events, which are defined as "noxious and unintended response to a medicinal product" by the
European Medicine Agency. Objectives: To identify studies describing at least one adverse event (or with potential to
promote an adverse event) related to the use of natural products, as well as to describe the involved product(s) and adverse
event(s).
Methods:
A pre-systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses
criteria. Keywords: "natural product(s)" and ["adverse drug reaction(s)" or "adverse effect(s)"]. Screened databases:
PubMed, SciELO, DOAJ and Google Scholar. Inclusion criteria: papers describing at least one adverse event associated
with the use of natural products and published between 2017 and 2019. Exclusion criteria: Repeated studies, reviews and
papers written in other languages than English, Portuguese, French or Spanish.
Results:
104 studies were identified (20 PubMed; 0 SciELO; 2 DOAJ; 82 Google Scholar), but only 10 were selected (4
PubMed and 6 Google Scholar): 1 in-vitro study; 2 non-clinical studies, 1 study reporting in-vitro and clinical data and 5
studies were cases reports. Globally, 997 reports of adverse drug reactions with natural products were identified, mainly
non-severe cases.
Conclusion:
Since a limited number of studies was found, we conclude that adverse events due to natural products may be
underreported, or natural products may have a good safety profile. This review contributes for assuring the safety of
natural products consumers, by evaluating the knowledge/information on the potential adverse events and interactions of
these products.