Billionaire entrepreneur Matthew Moulding's Hut Group has snapped up online skincare firm Dermstore from US retail giant Target for £259m.
Shares in the company - whose websites include the Lookfantastic beauty products business - soared more than 9% on the news.
Since it floated in September at 500p, its shares have risen more than 50%.
That triggered a massive £1bn payout for the boss, one of the biggest paydays in UK corporate history.
The company has grown rapidly by snapping up skincare and lifestyle brands while also operating online platforms for other brands.
It owns brands such as Glossybox and MyProtein and powers the websites of major businesses, including Honda and Nestle.
It said the purchase of Dermstore would "enhance its beauty strategy by substantially enhancing its relationships with the key global beauty brands".
"A key driver behind the decision to list THG on the London Stock Exchange just over three months ago was to enable the group to make major global investments," said Mr Moulding.
The Hut Group also added UK nutrition product suppliers Claremont Ingredients and David Berryman to its portfolio on Tuesday for £59.5m.
Claremont Ingredients operates a flavour manufacturing and development laboratory for sports nutrition and beverages, while the David Berryman business supplies and develops fruit-based ingredients.
Both companies had been suppliers for the Hut Group and the company said it bought them to support its commitment "to investing in and building best-in-class product innovation and manufacturing facilities".
Mr Moulding founded the Manchester-based business in 2004 selling CDs.
It now runs more than 100 websites and sells a range of consumer goods, from cosmetics to protein supplements.
In addition to his £1bn in shares payout, Mr Moulding is paid a basic salary of £750,000 a year, up from the £318,000 he took in 2019.
However, since the flotation, he has committed to donating his salary payments to charity.