An experimental male contraceptive

Male contraceptive

Male contraceptives include condoms, withdrawal , and vasectomy. In other animals, castration is commonly used for contraception...

 method involves heating the testicle

Testicle

The testicle is the male gonad in animals. Like the ovaries to which they are homologous, testes are components of both the reproductive system and the endocrine system...

s so that they cannot produce sperm

Spermatogenesis

Spermatogenesis is the process by which male primary germ cells undergo division, and produce a number of cells termed spermatogonia, from which the primary spermatocytes are derived. Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two...

. Sperm are best produced at a temperature slightly below body temperature. The muscles around a male's scrotum

Scrotum

In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...

 involuntarily tighten if the man's body temperature drops, and they loosen, allowing the testes to hang, if the body temperature rises. This is the body's way of keeping the sperm at an ideal temperature. Limited research has shown that raising the temperature of the scrotum above body temperature, even for short periods of time, can affect fertility for months.

Methods used include hot water applied to the scrotum

Scrotum

In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...

, heat generated by ultrasound

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

, and artificial cryptorchidism

Cryptorchidism

Cryptorchidism is the absence of one or both testes from the scrotum. It is the most common birth defect regarding male genitalia. In unique cases, cryptorchidism can develop later in life, often as late as young adulthood. About 3% of full-term and 30% of premature infant boys are born with at...

 (holding the testicles inside the abdomen) using specialized briefs

Briefs

Briefs are a type of short, tight underwear and swimwear, as opposed to styles where the material extends down the legs.In the case of men's underwear, briefs, unlike boxer shorts, hold the wearer's genitals in a relatively fixed position, which make briefs a popular underwear choice for men who...

. Initial experiments suggest it is effective, safe, and reversible, though there have not been long-term studies to determine if it has any side effects

Adverse effect (medicine)

In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...

 on the body or quality of sperm after reversal. The optimal heat level and time period of exposure are not known.

The method has a long history in Middle Eastern countries, particularly Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

.

External links

• From linked International Male Contraception Coalition and Male Contraception Information Project:
  • - A toxicologist's account of successful experiments on himself with suspensory briefs, also provides Excerpts from some research papers