A reversible contraceptive device for men that heats the inside of testicles with ultrasound is being developed in Germany, inspired by its creator’s frustration at the range of contraceptives available for men.
The Coso Contraception system involves testicles being submerged in water in a small bowl-like device. The device generates deep heat in the testicular tissue which, according to Coso creator Rebecca Weiss, modifies sperm mobility and temporarily inhibits the production of new sperm.
The hormone-free system is not available to the public yet, and its effectiveness has not been proven in humans, the company notes, rather importantly. Data from a 2012 study that showed that rats’ sperm reserves were depleted when exposed to ultrasound was used in its development.
Weiss, a design graduate of the Technical University of Munich, won a James Dyson award for the design in 2021.
“I was diagnosed with cancer precursor cervix due to contraception with the pill. After that, hormonal contraception was no longer an option. When my partner and I were looking for an alternative method, we became aware of the lack of male contraceptives. The problem is not unique to me personally. It affects many others as well. This is also evident in the current growing public discussion about the lack of contraceptive alternatives,” she says.
Although the Coso system is yet to be proved effective for humans, the makers have said that if it is rolled out, the first ‘ball bath’ session to use it will need to be conducted with a doctor. After that it will be able to be used at home, once every two months.
The makers claim that the system will be effective two weeks after the first testicle submersion takes place. Users who want to stop using the system and get their sperm up and running again will have to wait for a time “no later than six months” after their last ultrasound application.
It continued: “However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the result of repeated use, to verify that the contraceptive effect is reversible and to demonstrate that there are no detrimental, long-term effects from using ultrasound as a method of male contraception.”