‘I’ve physically not been able to put my arms down because the pain’s been so bad,’ Ellie says on TikTok.

She’d been using Mitchum’s 48-hour deodorant throughout the summer and began getting angry red marks under her arms and ‘weeping spots’.

‘The marks have been awful, not only unbelievably painful but also embarrassing for people to see, especially during holiday season,’ she adds.

What’s more alarming, is she’s not the only one having problems with the cult antiperspirant.

Ellie’s TikTok amassed 2.6million views in 24 hours, and is just one of countless videos sweeping the internet, where people are showing their armpits covered in the same red rash.

Another Mitchum user, Olivia, tells Metro: ‘After a few days of using it, I noticed I was getting a rash and really itchy underarms to the point where it was distracting me when I was trying to sleep.

‘The sensation was more like a stinging, like when you have dry hands and then use alcohol and gel on them – but the itchiness was the worst part.’

She’s since stopped using the roll-on and her irritation cleared up.

Another loyal Mitchum user of seven years (@marmite.12) had a similar reaction, claiming her pits were ‘on literal fire’ and she had an infection as a result.

Amongst the nearly 2,000 hashtags on the app relating to this issue, TikToker @summerx posted: ‘Mine was really bad to the point my whole armpit was blistered up and swollen. I’m left with permanent scarring on my armpits because of it!’

‘I’ve had the same issue,’ said TikToker Esmee Lewis. ‘Started off with awful burns that scabbed over, now they itch like crazy! I still can’t use deodorant… It’s awful.’

The brand’s Instagram page has also been flooded with comments over the past few days, claiming they’ve had burns on their arms.

What’s going wrong with Mitchum’s deodorant?

Discussion online centres on speculation that brand had changed an ingredient in it’s Mitchum 48-hour 100ml Roll-On anti-perspirant and deodorant formula — but Metro can reveal this isn’t the case.

In fact, we’ve solved the Mitchum mystery as the brand revealed the real truth to us.

‘We’re aware of reports from some customers regarding reactions to select batches of Mitchum 48-hour 100ml Roll-On anti-perspirant and deodorant sold in the UK, Ireland and South Africa,’ the brand tells Metro.

‘Consumer wellbeing is always our priority, and we are truly sorry some of our customers have experienced temporary irritation. This is not the experience they expect from us. We take this kind of feedback extremely seriously and have worked hard to investigate the cause.’

And now, Mitcham have finally got to the bottom of what’s going on.

‘We want to reassure there has been no change to the formula of our products, but we have identified a change in the manufacturing process affecting one of our raw materials,’ the spokesperson adds.

‘This has impacted how the roll-on interacts with the skin of some users.’

Mitchum says its now resolved the issue and it’s working to remove the products from the shelf, while also reverting to the original manufacturing process. This means you can buy Mitchum deodorant in peace, without having to worry.

It adds that it’s an isolated issue and that no other products it sells have been affected.

‘We ask that any consumers experiencing issues contact our Customer Care team and give us a chance to make this right,’ the brand says.

Why were we so loyal to Mitchum?

Since the brand was first launched in 1959 it’s become a cult product that thousands of us rely on to smell fresh. In fact, it’s the number one best seller on Amazon out of all antiperspirants.

It’s also been named one of the 16 best deodorants by Harpers Bazaar – that’s some pretty damning evidence.

Endorsed by the likes of Dr Alex, it’s popular for good reason. Redditors have dubbed it the ‘holy grail of antiperspirants’, purely because it does what it says on the tin – stopping you from sweating and smelling.

One customer said: ‘I’ve always used Mitchum roll-ons. They’re infallible, I never sweat or smell after I’ve used this.’

‘It took me ages to find the best deodorant and I now have this is it,’ another wrote.

So it’s not hard to see why so many were upset that their go-to solution for smelly pits was suddenly causing more harm than good.

At least we can all rest easy knowing we’ll soon be back to our regularly scheduled freshen up soon enough.

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