In France, they’re making DIY ‘heated briefs’ as contraception

It looks like a jockstrap crossed with a cock ring — like underwear that fits firmly over the groin, with a hole in the front to let the penis out. The testicles remain inside the garment, where they’re pushed upwards into the body so that their temperature rises.

This contraption is a homemade contraceptive device known as a “heated brief”. And as they wait for medically-approved birth control options, French people with penises are donning them to render themselves temporarily sterile.

Invented by a doctor, taken up by the masses

Erwan Taverne, 43, started thinking seriously about birth control after a former partner of his got pregnant accidentally.

“I first thought of having a vasectomy, but I was concerned about the reversibility of the procedure,” he says. “Then, on the internet, I read about contraceptive briefs, which Dr Mieusset in Toulouse had invented. So I got in touch.”

Inventor and andrologist Roger Mieusset designed the first heated contraceptive briefs in the 1970s, which worked by pushing the testicles towards the abdomen to raise their temperature.

While small, Mieusset’s studies show that when worn consistently over a number of months, the briefs can reduce sperm count to as low as one million per millilitre—which essentially amounts to infertility

For the testes to function normally, they need to stay at their regular temperature of around 34-35°C¹—which is about 2°C below our core body temperature (37°C).

But if the testes are pressed up into the abdomen the body can be used as a heat source, causing their temperature to rise to body temperature. This inhibits the production of sperm.²

While small, Mieusset’s studies show that when worn consistently over a number of months, the briefs can reduce sperm count to as low as one million per millilitre³—which essentially amounts to infertility.⁴

In a guide written about the method, Dr Mieusset recommended wearing the briefs for at least 15 hours a day and getting a spermogram every three months to check they’re working as they should.⁵

Over the past ten years, Dr Mieusset’s model has gained steam. Across France, workshops are being organised where people can learn how to sew their own contraceptive pants and tailor the design to their needs.

“Today, we lean towards a jockstrap model, which is more comfortable and simpler,” says Taverne, who has founded the Association Garcon, or Action Group for Contraception, an organisation which seeks to raise awareness about all different methods of contraception.

While he admits that it took a week or so to get used to, Taverne now swears by contraceptive briefs. He’s been using them as his primary form of contraception for seven years, alongside condoms to protect from STIs.

But, is it safe?

An untested method

From a medical perspective, thermal methods of male contraception make sense, says Dr Francois Isus, an andrologist specialising in male infertility. “Through an undergarment or a suitable, fitted device, the testicles are manually lifted in the groin. This causes the temperature of the testicles to rise, which slows down or stops the production of sperm”.

However, he warns, this method is yet to be tested in a clinical trial, so using it can come with risks. “To date, we don’t know the long-term effects of this method on fertility, its reversibility, or possible impact on testicular cancer.”

Without access to other forms of “male” contraceptives, people with penises have taken matters into their own hands

Another potential risk is that of an epigenetic effect on offspring: whether heated briefs could cause any changes to the testes that affect how genes are expressed in future generations. In theory, this could have wide-ranging impacts—such as increasing the risk of disease—but we don’t yet have the evidence to say for sure.

At the French Congress of Urology in 2021, doctors raised concerns about the increase in men using contraceptive briefs without fully understanding the potential side effects. At the time, Europe 1 reported that a clinical trial was taking place in Toulouse. However, the results have not yet been released.

Sharing the burden

Without access to other forms of “male” contraceptives, people with penises have taken matters into their own hands. The Action Group for Contraception estimates that between 5,000 and 10,000 folks are using heated briefs as birth control.

Taverne explains that there is a growing interest for the mental load of contraception to be shared between people of all genders.

“If birth control is a freedom, then why should only women benefit from it?,” he says. “And if it is a burden, why should they carry it alone?”

Start-ups have begun capitalising on this interest, and are putting forward their own thermal underwear products

While more groups and workshops are appearing throughout France, Taverne says that they’re struggling to meet demand.

Start-ups have begun capitalising on this interest, and are putting forward their own thermal underwear products. For example, Jemaya Innovations have created SpermaPause heated boxers. However, instead of raising the temperature of the testicles by pushing them upwards, the SpermaPause boxers contain electric heating pads.

Jemaya Innovations’ website sells and ships worldwide, yet founder Olivier Nago notes that their device still needs medical approval, meaning the company operates in a grey area. “Currently, [SpermaPause] is not recognised as a medical device. The certification process is arduous and would require long-term studies that have not been implemented yet”.

Because of this, Jemaya is not authorised to make medical information about these devices available to the public online.

Whether or not thermal underwear will be officially recognised as contraception remains to be seen, but their growing popularity shows the clear need for birth control options that cater to people of all genders.

Not only will people with penises then have control over their reproductive health, but this will free the rest of us from having to shoulder the burden of contraception alone.

Featured image is an illustration of a home-made pair of heated briefs

Page last updated March 2023