As global marketing campaigns go, getting Kim Kardashian to trigger a TikTok tidal wave of hype is probably about as good as it gets.
Australian teeth whitening brand HiSmile, dubbed 'purple shampoo for teeth', posted a video to its own TikTok page featuring the US reality star earlier this year.
The clip wasseen by 21.6million people, with Kardashian telling followers she was 'obsessed' with the brand's V34 foam product, which HiSmile says 'neutralises yellow tones on the tooth surface'.
The star was reportedly paid up to £500,000 ($640,000) for a single sponsored Instagram post.
The teeth whitening company, based on the Gold Coast in Queensland, has since seen its products - including fruity pastes, powders, serums and strips - fly off the shelves in UK branches of Boots and Superdrug, as well as online via Amazon and its own website.
TikToker @newhorizontwins revealed he couldn't see any difference after trying the toothpaste. While HiSmile has invested heavily into marketing - securing a collaboration with Kim Kardashian - the company has faced criticism over the product's effectiveness, and hundreds of complaints about delivery delays
@newhorizontwins replicated the front tooth dab seen in the glossy ads for HiSmile, which have seen the toothpaste, powders and strips go viral, but didn't get the same results, he says
A 30ml pot of the V34 pot promoted by Kardashian will currently set you back £19 at Boots or £15.20 on the HiSmile website - plus £4.99 delivery.
How does it claim to work? The brand's signature V34 toothpaste contains the active ingredient, Phthalimido Peroxy Caproic Acid (PAP) which, when oxidised, helps to break down stains and lighten tooth appearance.
The peroxide works by releasing molecules, known as free radicals, converting the colour of stained dental enamel to clear.
There are thousands of positive reviews about the product - including on both the Boots website and review website Trustpilot - and celebrities including Rita Ora, Rosie Huntington-Whitely, Millie Bobby Brown and Lily Allen have all sung its praises.
In a video promoted on HiSmile's own TikTok page, seen by 21.6million people, Kim Kardashian said she was 'obsessed' with the V34 foam product.Other celebrities who have been pictured with the product or have recommended it on social media also include Rita Ora, Rosie Huntington-Whitely, Millie Bobby Brown and Lily Allen.
However, in recent months, there seems to be a growing band of negativity around HiSmile, focused on both the product's effectiveness and customers reporting delivery delays.
The social media platforms that originally made the product so popular are now off-setting at least some of that heavy marketing investment it seems - with TikTok dentists and product reviewers offering a less positive spin on the best-selling purple serum and HiSmile's other products.
One half of TikToker @newhorizontwins revealed he couldn't see any difference after trying the toothpaste. The social media star, who has 1.8 million followers on the account he shares with his twin brother, replicated the front tooth dab seen in the glossy ads for HiSmile but didn't get the same results, he says.
He told followers that while he would give the paste the benefit of the doubt, the glowing white tooth seen in the ads hadn't materialised for him.
The Australian teeth whitening brand, HiSmile, claims their V34 foam can 'colour correct' teeth in the same way purple shampoo helps tone down brassy hair tones. Now stocked in Boots, the product also 'neutralises yellow tones on the tooth surface', the company adds.But it also offers a separate range of flavoured toothpastes from £6 in watermelon, mango sorbet and peach iced tea flavours
The British Dental Association said effective teeth whitening is best sought out in a dental practice and not with over-the-counter products
HOW DOES HISMILE'S BEST-SELLING V34 PRODUCT WORK?
The brand's signature V34 toothpaste contains the active ingredient, Phthalimido Peroxy Caproic Acid (PAP) which, when oxidised, helps to break down stains and lighten tooth appearance.
The peroxide works by releasing molecules, known as free radicals, converting the colour of stained dental enamel to clear.
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One British user posting on TrustPilot last move offered just one-star, saying: 'Please please please don’t waste your money on these products! I bought a whitening toothpaste done absolutely nothing.'
Another Brit posted on the review site, saying: 'I was taken in by all the great reviews paid my money when arrived couldn’t wait to try it then absolutely no difference tried for two weeks to give it a good try but still no difference please do not waste your money.'
And another this week focused on an apparently shoddy delivery service, saying: 'Companies can face difficulties when scaling up. But this is just ridiculous. Don't expect any sort of support from their side concerning your order, or any other enquiries.'
MailOnline spoke to the British Dental Association about whitening products in general.
The BDA haslong campaigned for tooth whitening to remain 'the practice of dentistry to ensure patients are protected'.
The organisation said: 'Dangerous levels of hydrogen peroxide are the equivalent of brushing with bleach and can put oral health at risk.
'Trading standards attempts to regulate the flow of these products onto our shelves, but it is a mammoth task and some online products being sold in the UK have been found to contain dangerous chemicals, which are toxic or banned, that can severely burn your gums and damage your teeth.'
British Dental Association chair Eddie Crouch told MailOnline: 'At best people will just waste money buying over the counter and online products to get whiter teeth.
'At worst you can end up on the receiving end of toxic or banned chemicals, that can damage your teeth and severely burn your gums. For safe and effective whitening visit your dentist.'
MailOnline has contacted HiSmile for comment.
