Italy's competition authority has opened investigations into LVMH-owned Sephora and Benefit Cosmetics over the marketing of adult beauty products to children, saying the practices were fuelling an obsession with skincare among minors, including some under 10 years old.

The AGCM said it was the first European regulator to open an investigation over concerns the brands are using very young micro-influencers on social media to promote premature use of adult cosmetics and encourage compulsive purchasing of face masks, serums and anti-ageing creams, behaviours it linked to "cosmeticorexia" - an unhealthy fixation with skincare among minors.

Sephora, Benefit Cosmetics, and LVMH Perfumes & Cosmetics Italy will fully cooperate with the authorities, an LVMH representative in Italy said, declining to give any further comment.

Beauty retail giant Sephora, which has more than 20 million Instagram followers and 2.1 million followers on TikTok, has been at the centre of the "Sephora Kids" social media trend documenting children making cosmetic "smoothies" in stores and sharing their skincare routines or their Sephora "haul" purchases in videos.

The "Haul from Sephora for Kids" tag on TikTok shows hundreds of videos of children as young as five buying make-up and skincare products in Sephora stores.

"The investigations were opened over concerns that important information – such as warnings and precautions for cosmetics not intended for, or tested on, minors – may have been omitted or presented in a misleading manner," AGCM said in a statement, adding that children under the age of 10 to 12 were among those the brands are targeting.

Frequent use of a wide range of cosmetics by minors without proper awareness may be harmful to their health, the regulator said.

AGCM officials and the Italian financial police carried out inspections at the premises of Sephora Italia, LVMH Profumi e Cosmetici Italia and LVMH Italia on Thursday, the authority said.

-Reporting by Enrico Sciacovelli and Helen Reid, Editing by Jan Harvey, Barbara Lewis and Louise Heavens/Reuters