Dragons' Den has transformed some incredible ideas into hugely successful businesses over the years.
However, while the multi-millionaire Dragons have an eye for a lucrative business opportunity, they haven't always got it right, and have missed out on quite a few chances to take some ingenious ideas to their full potential
Keep reading for the most profitable businesses we bet they're still kicking themselves for missing out on...

BrewDog
In 2008, James Watt and Martin Dickie applied to be on Dragons' Den with their craft brewing business, Brewdog. Though the pair were invited for a screen test, the producers weren't confident in the idea, so the idea was never even brought to the Dragons.
"We were prepared to offer the Dragons 20 per cent for £100,000," then-CEO James wrote on LinkedIn back in 2021. "Based on our latest BrewDog valuation, that investment would now be worth almost £360m, meaning that the dragons missed out on by far the best deal in den history."
Through their audacious marketing tactics, including punk references and a viral video in a penguin suit, the friends managed to build a corporation that was worth £2 billion in 2023, according to The Sun.

Trunki
We bet you've seen the colourful ride-on children's suitcases that have taken families by storm.
Founder Rob Law pitched the business to the Dragons in 2006, but when Theo Paphitis broke a strap on one of the cases, they were told that the design needed some more work and turned away.
Even though Richard Farleigh offered £50,000 in return for 10 per cent equity, Rob was hoping for a £100,000 investment, and decided to take the idea elsewhere.
Since then, Trunki has become a multi-million pound company, won over 100 design awards and was sold in 2023 for £12 million.

Oppo Ice Cream
Though their idea for a low-calorie and 'guilt-free' ice cream range was turned down by the Dragons in 2016, the founders of Oppo Ice Cream were backed by other massive investors, including Richard Branson and Andy Murray.
At the time, Charlie and Harry Thullier sought a £60,000 investment for a seven per cent equity stake, and left the den empty-handed. After a series of crowdfunding attempts, they had 538 investors and were reportedly worth nearly £86 million by 2022.

Hungryhouse
There may be lots of online takeaway and delivery services now, but back in 2007 when Shane Lake and Tony Charles pitched Hungryhouse, the idea was something completely new.
The two secured an offer of £100,000 from James Caan and Ducan Bannatyne, in return for a whopping 50 per cent stake in the business, but the deal fell through during post-show negotiations.
Fortunately, Shane and Tony raised £150,000 from other investors and, in just three years, increased the number of partner restaurants from 150 to 2,500. In 2016, the company was bought out by Just Eat for an impressive upfront payment of £200 million.

Prestige Pets
Natalie Ellis brought the pitch for non-spilling dog bowls to the Dragons back in 2008. Seeking a £150,000 investment in return for a 15 per cent share, she was told that there was little chance for profit and turned away.
The Dragons specifically scoffed at her plan to bring the product to the US market - fortunately for Natalie, they were completely wrong to do so.
The plan turned her into a multi-millionaire with a wealth of celebrity clients including Princess Anne and former President Barack Obama. Even Deborah Meaden came around eventually!