Rebecca Infusino, Mustela USA’s Sales and Marketing Manager, told us, "Britney most likely purchased two post partum favorites, Mustela 9 Months Stretch Marks Intensive Action which reduces existing stretch marks particularly as a result of childbirth, along with our Post Partum Body Restructuring Gel which restores the firmness of the tissue." 

Mustela 9 Months is the only comprehensive skin care line for pre- and post-natal moms, and features Lupeol, a plant extract that which they say stimulates the production of collagen and ensures its quality.  The Mustela 9 Months line is available nationwide and ranges in price from $19-$37.