Male Contraception – Turning sperm ‘on’ and ‘off’

male contraception

Could it be possible to switch off sperm flow to prevent unwanted pregnancy? German born carpenter Clemens Bimek believes it can be done and his device, the ‘Bimek SLV’, is set for clinical trials in 2016.

Could this be the answer men have been looking for in reliable male contraception?

Current male contraception options

When it comes to male contraception there are few options available. Condoms are the only current option to men that don’t want to start a family but would like to option to do so in the future. A vasectomy will prevent unwanted pregnancies; however this is not a procedure that can be easily reversed.

Over the years researchers have been working on developing the male equivalent of the female contraceptive pill. New clinical trials are now underway to test various versions of the ‘male pill’.

Scientists are also attempting to develop implants and injections similar to those used by women to stop conception. These work by altering hormone levels, making it difficult to fall pregnant.

However, despite the best efforts of researchers there has not yet been a breakthrough in male birth control. Even if the current efforts in male contraception prove to be safe and effective, it is still unlikely that they will be widely available for many years.

Introducing the Bimek SLV ‘sperm switch’

Twenty years ago Clemens Bimek started working on developing a male contraception device. The Bimek SLV was later patented in 2000. This device is a mechanism designed to offer short-term sterilisation at the press of a switch.

Since 2009, Mr. Bimek has been using the Bimek SLV to successfully control his fertility. Over the years the device has been refined.

Mr. Bimek has the backing of investors who want to see this product become the first successful global male contraception implant. With clinical trial scheduled for 2016, the company is aiming to have this product available as early as 2018.

Operating the Bimek SLV

Measuring less than an inch long, the Bimek SLV is a small device. It consists of two valves and weighs a little under three grams. To use the Bimek SLV it must be surgically attached to the vas deferens. This is the duct responsible for carrying sperm to the urethra from the testicles.

Once implanted, the Bimek SLV sits under the skin beneath the scrotum. From here the patent can access the “on-off” switch. When activated the valve will shut and prevent sperm from ejaculating. The sperm is diverted back to the scrotal tissue for absorption.

This successfully creates a situation of forced sterilisation. However, sperm can re-enter the vas deferens and travel through to the urethra for ejaculation by turning the switch off. This, unlike a vasectomy this male contraception is reversible.

The animation below demonstrates how the Bimek SLV operates:

The future of the Bimek SLV

As first glance the Bimek SLV male contraception device appears to offer a viable solution to men who want to have more control over their fertility. However, there are many aspects of this technology that require further testing.

Some doctors have raised their concerns about potential vas deferens scarring following implantation of the Bimek SLV. If severe, this could prevent the return of sperm transport even if the valve is no longer closed.

Blockages within the valve are also a potential problem. It is also not well understood how the body may react to the materials used in the construction of the Bimek SLV. As with any surgical implant there may be adverse allergic reactions.

Another consideration is sexually transmitted diseases (STDs). The Bimek SLV does not offer any protection from STDs.

Although there are concerns associated with the suitability and effectiveness of the Bimek SLV, many medical practitioners are also optimistic. Unlike other male contraceptive options currently being investigated, the Bimek SLV does not alter hormone production. This can eliminate any adverse side effects associated with hormonal changes.

Research has shown that the failure rate for condoms is high at around 18% per year1. The Bimek SLV is expected to be more reliable and significantly reduce the risk of unwanted pregnancies.

Other than abstinence, the only truly reliable male contraceptive is a vasectomy. However, this is a surgical procedure that is difficult to successfully reverse. Consequently it is not an option for men that would like to start a family at a later date.

The results of the upcoming clinical trial of the Bimek SLV will be eagerly anticipated. Men (and women) will be interested to know if this device is going to be a viable male contraception option. Once the findings are available, we will provide you with an update.


  1. “Trussel, J. (2011). Contraceptive failure in the United States. Contraception – an international reproductive health journal, Volume 83, Issue 5, (pp. 397-404).”
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