Salma Hayek believes people often "underestimate" her in the beauty business because of her acting background.

Despite having released her own line of skincare products called Nuance Salma Hayek, and having co-founded popular juice cleanse company Cooler Cleanse, the 45-year-old mother-of-one still feels that people don't always take her seriously.

"Because I have a background in a different field, it can be hard to negotiate and make a good deal for myself. People always underestimate me. But if you stick around long enough, act out of conviction, and try to be honorable in everything you do, good things will come to you. I have seen karma work in this business," she said.

Nuance features 100 different products from cleansers and spot treatments, through to anti-aging creams and cosmetics, and as the granddaughter of a Paris-trained cosmetologist, Salma worked on each item from start to finish: "I don't know that many people in my position who would actually put that much time into it. It's a lot easier to get a contract or say that you are doing the work when it's really someone else. I don't think my own agency - or even I - knew how stubborn I was going to be."