Fathead minnow life cycle exposure to environmentally relevant concentrations of metformin shows no adverse effects

This study aimed to determine whether the pharmaceutical metformin had toxicological effects on the fathead minnow (Pimphales promelas) in their various life stages—from eggs to adulthood. Endpoints included survival, growth, and reproductive development. Fathead minnows were exposed to metformin at concentrations 3, 31, and 322 micrograms per liter (ug/L) for a total of approximately six months.

Exposing the fish to metformin from egg stage did not adversely affect early survival and did not affect growth or development compared to the controls. There were very few significant differences in length, weight, and condition factor and it did not significantly affect maturation rate, or overall egg production. The findings of this study indicate that metformin does not adversely affect fathead minnow reproduction or cause intersex gonads.

All data are a part subject of a publication containing method details, full QA/QC, interpretation, and conclusions: Parrott JL, Pacepavicius G, Shires K, Clarence S, Khan H, Gardiner M, Sullivan C, and Alaee M. 2021. Fathead minnow exposed to environmentally relevant concentrations of metformin for one life cycle show no adverse effects. FACETS 6: 998–1023. doi:10.1139/facets-2020-010

Supplemental Information

The Chemicals Management Plan (CMP) is a Government of Canada initiative aimed at reducing the risks posed by chemicals to Canadians and their environment. A key element of the Chemicals Management Plan is the monitoring and surveillance of levels of harmful chemicals in Canadians and their environment. Monitoring and surveillance are essential to identify and track exposure to hazards in the environment and associated health implications. Monitoring and surveillance programs provide the basis for making sound and effective public health and environmental health policies and interventions, as well as measuring the efficacy of control measures.

In support of the Chemicals Management Plan, monitoring and surveillance initiatives were established to support Health Canada and Environment and Climate Change Canada scientists, in collaboration with external partners and researchers, to advance our knowledge. This initiative has allowed the Government of Canada to increase its commitment to a number of existing monitoring initiatives, as well as to support new efforts.

For more information on the Chemicals Management Plan, please visit https://www.canada.ca/en/health-canada/services/chemical-substances/chemicals-management-plan.html