Dienogest
Summary
Persistence. Dienogest is persistent.
Bioaccumulation. Dienogest has low potential for bioaccumulation.
Toxicity. Dienogest has very high chronic toxicity.
Risk. It is unlikely that the current sales data of dienogest pose an environmental risk, but it cannot be excluded that a significant increase in sales of dienogest could change the risk. Dienogest is a testosterone derivative. At the same time, dienogest is not an agonist of the human androgen receptor (but an antagonist). Dienogest binds poorly to SHBG and has lower lipid solubility than all other progestogens examined, which suggests limited bioconcentration potential in fish. From a Stockholm, Sweden perspective.
This summary information comes from Fass. The risk is from the report by Goodpoint.
Detailed information
Fass environmental information
Fass environmental information for dienogest from Qlaira (dienogest, estradiol) from Bayer (downloaded 2025-03-27).
Hazard
Persistence: "Dienogest established a DT50 > 120 d for the total system and is resistant to hydrolysis, which qualifies for hydrolysis the phrase “dienogest is potentially persistent.”" The database, Pharmaceuticals and Environment, reference group believes that based on these results, a drug substance is persistent and not potentially persistent, hence the information that dienogest is persistent in the initial summary information.
Bioaccumulation: Log P 1.6 at 7 (OECD 117).
Toxicity: There are data for 3 trophic levels, most sensitive fish (Pimephales promelas) NOEC = 0.036 microg/L.
Risk
PEC/PNEC is based on sales data in Sweden in year 2021. PEC/PNEC = 0.64 which gives the risk low.
Report Goodpoint 2024
It is unlikely that the current sales data of dienogest pose an environmental risk, but it cannot be excluded that a significant increase in sales of dienogest could change the risk. Dienogest is a testosterone derivative. At the same time, dienogest is not an agonist of the human androgen receptor (but an antagonist). Dienogest binds poorly to SHBG and has lower lipid solubility than all other progestogens examined, which suggests limited bioconcentration potential in fish. From a Stockholm, Sweden perspective. See also the report, which lists various recommended alternatives in the Wise list, from best to worst from an environmental point of view.
Author: Health and Medical Care Administration, Region Stockholm