That explains the unexpected bump up in sales of Waitrose Baby Bottom Butter, the Daily Mail reports. The butter costs about $5, far less than designer face creams.

The new use for the butter was promoted on parenting Web sites.

"I can't even remember what made me put it on my face one day but OMG -- it is fab," one fan wrote on mumsnet.com. "I have been using it constantly for 2 weeks now and my skin now has the smoothest texture, which I don't think it's had since prepubescence."

The woman said it also did wonders for the makeup she put on top of it.

Some users complained of different results -- that they looked greasy or developed acne.

The butter is part of Waitrose's all-natural line of baby products, with olive oil, chamomile and lavender.