A few states, including California and Florida, permit convicted sex offenders to be injected with Depo Provera, an FDA-approved birth control drug. Often called “chemical castration,” Depo Provera is meant to quell the sex drive of male sex offenders by lowering their testosterone levels. The drug does not render any permanent physical change to the body. The treatment is believed to be most effective on sex offenders who possess uncontrollable biological urges that take the form of sexual fantasies that are usually only satisfied by acting on the fantasy.

Both the California and Florida statutes provide for mandatory injections for repeat sex offenders, as well as discretionary injections for first-time offenders. Despite the mandatory language in the Florida law, the law has apparently been invoked only a few times since its passage in 1997.

Critics, including the American Civil Liberties Union (ACLU), charge that chemical castration violates sex offenders’ constitutional rights. The ACLU contends that chemical castration violates an offender’s implied right to privacy under the Fourteenth Amendment, rights of due process and equal protection, and the Eighth Amendment’s ban of cruel and unusual punishment.

Pursuant to a 1997 law, Texas permits surgical castration of offenders. By May 2005, three men had undergone the voluntary procedure. Candidates must be at least 21 years of age, have had at least two sex offense convictions, and have undergone at least 18 months of sex offender treatment, including Depo Provera injections, to understand how their bodies might react with less testosterone.