The Sin City beauty co-founded the business, which sells non-toxic items including diapers, household cleaners and beauty products, in 2012 after previously suffering a bad reaction to chemicals used in a baby detergent while pregnant with her first child in 2008.

In just one year, it raked in $10 million (£6.3 million) in revenue.

The Honest Company's profits continued to soar and last summer (Aug14), experts valued the firm at just under $1 billion - a figure which has since been surpassed, but Alba insists she is only getting started.

She tells the publication, "If we really want to make a difference in the world and people's health, it's billions and billions of dollars, not just one."

Ironically, despite being the cover girl for the America's Richest Self-Made Women issue, Alba just missed out on making Forbes' top 50.

Oprah Winfrey is the highest-placed celebrity at five with a net worth of $3 billion, while Madonna is at 28 with $520 million (£325 million), and Beyonce ties with TV's Judge Judy for 49th place, with $250 million (£156 million).