One of the industry's best-kept secrets, serums are fast becoming the new darling of women around the country - thanks to a little Boots number that is rapidly flying off shelves nationwide.

Sales of No7 Protect & Perfect Serum increased by nearly 2,000%, with 13 being sold every minute, after it was touted by the BBC Horizon programme as a 'wonder cream' that reduces wrinkles.

But beauty insiders aren't too surprised by the sudden popularity of serums.

Dr Barry Cohen, founder of pH Advantage, says: "The molecules in a serum are smaller than that of a traditional moisturiser, and therefore, are able to absorb more effectively into the skin's pores."

Concentrated ingredients are packed into a serum, which can penetrate the skin much quicker and more deeply for an intensive treatment. They can also help to address certain skin problems, such as dehydration and dullness.

To get a serum's full benefits, you should add a drop onto cleansed skin before applying your moisturiser in the morning, and again before you sleep at night.

- See the best serums for your skin and hair