Do you fancy munching your moisturiser? Or tasting your toner? The latest trend in the world of cosmetics is to create products so natural that you could put them on your toast.

In fact, some sound more like superfoods than toiletries. Ila, an organic skincare range that claims to be 100 per cent chemical-free, has a face oil that contains essential fatty acids as well as antioxidants.

But does this mean that we should be scrutinising the labels on our cosmetics in the same way we do the ingredients in our food? Does it matter whether the creams and lotions that we put on our skin are as pure as what we eat?

Dr Saulius Alkaitis, a Los Angeles-based skin specialist, says yes, in no small part because he makes a range of products that have been dubbed “therapeutic skin food”. Big in the US, his Alkaitis range (www.alkaitis. co.uk ) has just gone on sale in the UK. His mantra is “if you can't eat it, don't put it on your skin”, and he claims that all his products, from moisturisers to beauty serums, are edible (although I can vouch that they don't taste great). A chemist by training, Dr Alkaitis worked in molecular biology and cancer research before moving into cosmetics.

“My wife kept bringing cosmetics home and saying to me, would you put this on your face? I looked at the ingredients and said no because I wouldn't want to use something so harsh on my skin.” Spotting a niche in the market for natural face creams, he spent six years formulating from plant extracts the products in his skincare range.

Create your own range

Pat Thomas, editor of The Ecologist magazine and the author of Skin Deep: The Essential Guide to What's Really in The Toiletries and Cosmetics You Use, thinks that we should ditch beauty products altogether. She says we should concoct our own from natural ingredients such as jojoba and rosehip oil because the potentially toxic ingredients in commercial cosmetics can enter our system via our skin.

“Up to 60 per cent of whatever you put on your skin gets absorbed into your body,” she claims. “Remember we use things like nicotine patches and oestrogen patches precisely because the skin can absorb all kinds of things. If the skin was a barrier, rather than a sponge, these patches wouldn't work.”

But do all creams enter our system as nicotine does? Dr Nick Lowe, a consultant dermatologist with his own range of face creams, says no, nicotine and oestrogen are made from very small molecules and to assume that cosmetics act in the same way as a nicotine patch is wrong. Covering the skin with a patch for a prolonged period makes it more sponge-like and permeable to chemicals, resulting in the ingredients being absorbed. However, we don't cover our face in, say, clingfilm after using a face cream.

“The skin is an efficient barrier,” he says. It consists of many layers, but only the upper layer, called the stratum corneum, is permeable to cosmetics. This is why applying any type of moisturiser, from the cheapest to the most expensive, will reduce fine lines as it hydrates the skin and plumps it up.

The layers beneath the top layer, however, are much less permeable, which is why deep wrinkles are so difficult to tackle with a cream; many of the ingredients simply won't reach them.

Dr Lowe adds that all cosmetics have to abide by the strict regulations that govern cosmetic manufacturing, which means that no toxic ingredients can enter the mix. “You can't include any old thing you fancy,” he says. They also must come from a list of European-approved ingredients and stay within amounts set by European guidelines.

Dr Chris Flower, the director-general of the Cosmetic, Toiletry and Perfumery Association, the trade association that represents the cosmetics industry, says that it is in the interest of the cosmetics companies to ensure that a product is safe.

However, he says that even in the unlikely situation that all of the ingredients are absorbed through the skin, this does not automatically equate with damage to the body. “Your body gets rid of chemicals very quickly; most are broken down and excreted,” he says.

Leave deep lines to Botox

Your skin's inability to absorb creams and lotions at a deep level means that they never will be hugely effective at treating deep lines and wrinkles - leave that to Botox. But it also means you don't need to worry that your moisturiser is as pure and organic as your food.

Kate Wighton is science editor of Body&Soul

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