The Coso “testicle bath” is ultrasound-powered contraception for men

Coso is a reversible, and hormone-free male contraceptive device that temporarily neutralises sperm.

Male contraception as a taboo subject is unwarranted, which has today left men with little more than two options: condoms or a vasectomy. The Coso ultrasound bath could have the power to change that.

German designer Rebecca Weiss has developed Coso, an ultrasound-based, reversible, and hormone-free male contraceptive device for home use that temporarily modifies spermatogenesis.

Here is how it works. First, the user fills the device with water up to the indicated mark, which is set together with a doctor according to individual testicle size.

Then, the device can be turned to heat the water to operating temperature.

Coso is then ready for ultrasound treatment, inviting the user to sit for a few minutes with their testicles dipped into the water.

The ultrasound waves temporarily halt sperm regeneration, with contraceptive effectiveness beginning two weeks after the first application.

According to Weiss, the ultrasound contraceptive should become effective within two weeks and last for at least two months. Fertility would return to normal six months after the last treatment.

Coso is visually unassuming with its small bowl-shape discreet navy blue colour palette, which looks similar to other domestic gadgets.

These decisions were evaluated with users during the research and development phase.

Other features were included because they were necessary to the product’s function, including an auto-shutoff after treatment, and a battery, microcontroller, ultrasound module and LED strip, which are all included in its base.

There’s also a status display in the well providing a user interface and an accompanying app to monitor progress.

And as for the science behind the device, that’s based on research that found ultrasound contraception has been successful on animals, but has so far been untested on humans.

Weiss hopes her design promotes further testing, which will in turn need financial support. 

Discreet design for intimate products is on vogue, also for sex toys like the Crescendo by MysteryVibe.

Coso 'Testicle bath' - male contraception
Coso is visually unassuming with its small bowl-shape discreet navy blue colour palette, which looks similar to other domestic gadgets – ©COSO

COSO: The future of male contraception?

This ultrasound contraceptive device provides a user-friendly approach to contraception that is easy to use without any kind of physical intervention, pain, or previously known side effects.

It’s worth noting that using a condom in conjunction with this device is probably preferable as it only theoretically protects from unwanted pregnancies and not any potential STI’s.

It has so far won a James Dyson Award for innovation but Coso is still a concept design, and it is a long way off being launched, as thorough clinical trials would need to test it.

Whether it is released depends on the results from these clinical studies.

Nevertheless, hopefully Coso works and becomes a reality because a male birth control method is long overdue.

If trials are successful it could help remedy gender inequality when it comes to contraception.

Another contraceptive method is to track ovulation. A new way how to predict and identify this is with the kegel ball from kegg.