structural:reformatting, quality:corruption
Pharmacological

In the 1977 textbook Ecoscience: Population, Resources, Environment, on page 787, the authors speculate about future possible oral sterilants for humans.

In 2015, DNA editing using gene drives to sterilize mosquitos was demonstrated.

There have been hoaxes involving fictitious drugs that would purportedly have such effects, notably progesterex.

See also Norplant, Depo-Provera and oral contraceptive.

Chemical, e.g. drug-based methods are available, e.g. orally-administered Lonidamine for temporary, or permanent (depending on the dose) fertility management.Boris provides a method for chemically inducing either temporary or non-reversible sterility, depending on the dose, "Permanent sterility in human males can be obtained by a single oral dosage containing from about 18 mg/kg to about 25 mg/kg".