Black ice cream makes birth control less effective

Charcoal ice cream is all the rage on Instagram.

The black treat has been hailed as the antithesis of the hackneyed unicorn trend. 

It is part of a wider trend that has seen activated charcoal - a detoxing agent - crop up in juices and salads.  

However, just as summer gets into full swing, a petition is calling for gelaterias to stop serving the ebony-hued soft serve or add a warning label - claiming it could tamper with a woman's birth control.

The claim is not unfounded. 

Activated charcoal has been used for decades in hospitals to detox patients, perhaps from an overdose. 

The substance is an absorbant, meaning it sucks out the toxins from your stomach. 

But it can also absorb medications, including birth control pills. 

'Activated charcoal can actually make your birth control and other prescription medicines less effective,' the petition reads. 

'Yeah: if you eat activated charcoal shortly after taking a hormonal contraceptive, you could wind up pregnant.'

The petition has reached 19,993 supporters in two weeks.  

According to gynecologist Dr Alyssa Dweck, author of The Complete A to Z for your V, there is a risk - but not in small doses. 

'If you're having charcoal ice cream once a month, I wouldn't worry about it. For charcoal to absorb medication, we're talking about medical-grade levels of charcoal. Ice cream will not have that month.'

That said, she added, 'if you're having charcoal ice cream twice a day or every day, then yes, you should not rely on your birth control to be the most effective - but that would be a lot'.

'Ultimately there is very little information on it,' Dweck added. 'But I would say that if you're worried about it, then use a condom.' 

Follow NEWS.am Medicine on Facebook and Twitter