The £125 'Boob job' gel promises to plump, firm and lift boobs by as much as 2.5cm if applied daily for 56 days.
Makers Rodial claim it works by blocking fat cells as they travel round the body, increasing a woman's bust size.
Celebrity fans of the gel are said to include Scarlett Johansson, Eva Mendes, Victoria Beckham and Kelly Brook.
Before you ask, no, we don't think Scarlett Johansson will need to take you up on your kind offer of rubbing it in for her.