Longtime hair guru to Julia Roberts, Sarah Jessica Parker, Ellen Barkin, and a slew of other follicularly blessed celebs, Serge Normant has finally bottled his magic. His eponymous hair product collection launches this month at sergenormant.com.

What’s your definition of good hair?
Strong, healthy hair is the ultimate in glamour. In the formulas we used a vegetable-derived strengthening complex called Keravis, which is made up of small particles that actually penetrate, rather than just coat, the hair shaft. I worked with a skincare chemist because hair is an extension of skin.

What’s the biggest mistake women make when it comes to their hair?
Too much gel. I know frizz is hard, but covering the hair with too much stuff isn’t the answer. I like to look at a woman’s hair and wonder if she’s wearing any product at all.

Which products are you most proud of?
Pomade. People have a hard time with pomade, but mine’s not greasy. It adds texture and definition without making hair look stringy. And the Sheer Dry Oil Finishing Spray, which was inspired by a dry body oil I found in France and imparts a great weightless shine.

All of the names contain the word “meta”—Meta Silk Shampoo, Meta Luxe Hair Spray. Why?
Photographer Michael Thompson always makes fun of me for describing everything as “beyond.” When I learned that “meta” means “beyond” in Greek, I knew I had to work it in.

Does everyone who sits in your salon chair want Julia’s hair?
Yes. Hers and Ellen’s. People come in with tear sheets all the time, which I love. Even if it’s another stylist’s haircut, I don’t care. Hairdressers shouldn’t be offended by that. Orlando, Garren—I respect those guys. They’re great artists.

What was the best day of your career?
I know you want me to say when I met Sarah or when I met Julia, but honestly it was my first day working at a salon. I was 15, and I still remember the smell of it. I did the coat check. I thought, Oh, my God, I’m actually going to be able to work doing what I love!