The truth about 'the science bit'

Hair-care laboratories spend millions developing 'miracle' shampoos that claim to flatten, thicken and gloss our locks. But can they prove it? The Independent's technology editor Charles Arthur sorts his Nutrileum from his Quaternium

" Hello," I say to the woman who answers the phone on the Pantene shampoo helpline. "Could you explain to me what a pro-vitamin is, and why it would make any difference to my hair?"

" Hello," I say to the woman who answers the phone on the Pantene shampoo helpline. "Could you explain to me what a pro-vitamin is, and why it would make any difference to my hair?"

Her database reveals no answers. "Ooh, I don't know," says the Pantene woman. "I just help consumers with their questions. I'll call you back."

It seems odd that no one has thought to ask the Pantene helpline about pro-vitamins before, because its adverts make much of them. Apparently, Pantene Pro-V shampoo "has a unique pro-vitamin formula to smooth and align every strand". But what are pro-vitamins? Do all the other callers already know these vital details, and seek more urgent advice?

I query the internet with some of the other phrases that a little light skimming of hair products will uncover. Ever heard of Nutrileum? Quaternium? Nutri-ceramides? They sound like something in an announcement from the Home Office: "Police have arrested three men who were trying to smuggle deadly Nutrileum and a quantity of nutri-ceramides into the country..." None of them figured in the periodic table I learnt at school, but maybe things have moved on...

Certainly, the shampoo business has. The big breakthrough in hair science took place in the 1980s, when scientists at Procter & Gamble developed a combination of shampoo and conditioner. Previously, the chemicals required for each were antagonistic, like lemon and milk, and so they were sold in separate bottles, but P&G found a way to combine them. So was born Wash'n'Go - and the end of two-bottles-in-the-shower misery. What do you mean, you weren't miserable?

These days the annual UK haircare products business is worth a staggering £1.6bn. We spent £352m on shampoo alone last year, from a selection of more than 200 varieties, and a further £218m on conditioner. The sums vastly exceed what we spend on any other part of our bodies. So it's telling that among the items sent to the England football squad for Euro 2004 were 24 bottles of hair mousse and plentiful supplies of shampoo - and about half the team are shaven-headed.

With so much at stake, one would expect that some sophisticated science is needed to sell what might seem to be identical products. Some shampoos cost more than 30 times as much as others - from 9p per 100 millilitres for Tesco's cheapest, say, up to £3.32 per 100ml for Redken Colour Extend.

Dozens of brands jostle for position, though almost all belong to a few big names: the multinational Procter & Gamble, the chemicals conglomerate Unilever, and the French company L'Oréal. The last of these had the foresight to hire Jennifer Aniston to promote their shampoos at the height of her fame as Rachel in Friends - which, arguably, is responsible for the current emphasis on "the science bit" in just about all cosmetics advertising.

The Pantene woman rings back. It has taken her only a couple of hours to find out the answer to my question, which apparently is this: "Although hair is dead, it needs to be maintained. The pro-vitamin helps close the cuticles to make it look nice and shiny." So what exactly is a pro-vitamin? She considers this for a moment. "Although hair is dead, it needs to be maintained..." she begins. I thank her and ring off.

I tap "Nutrileum" into Google. It would be nice to discover the exact scientific explanation of what L'Oréal is selling us, but nobody seems to know, including L'Oréal's website and its spokeswoman, who tells me that "it's meant to indicate that it's nutrition, for the hair", but then lapses into silence when asked why something that's dead should need nutrition.

Pro-vitamins, it turns out, are the precursors to vitamins, but are only transformed into vitamins in the gut or in the blood. Not much will happen to them on your head.

But what about nutri-ceramides, or even plain old ceramides? In 1999, the Advertising Standards Authority ticked off L'Oréal for suggesting that ceramide - "the hair's natural strengthener" - was what made your hair strong. Yet the ASA rejected a similar complaint over L'Oréal's claims that ceramide-R in its shampoos could strengthen hair, even though test results submitted by the company used 10 times the concentration of chemical found in the product.

When the Consumers' Association's Which? magazine studied the type of scientific claims found on cosmetics in 2003, it found that while "some claims may be backed by scientific studies in the laboratory, differences may not be observable by the consumer". Where the claims were backed up by market research, an expert noted that "it is difficult to know whether users really believe what they're saying, or whether they're happily feeding back the results of previous advertising".

Which?'s own tests found that shampoos claiming to add "volume" to limp hair did no better than shampoos for normal hair. Those that claimed to remove the "build-up" of styling products performed just the same as any other detergent. And those claiming to prevent or treat hair loss left the experts unimpressed. Men battling baldness with hair restoratives containing chemicals such as minoxidil seemed to work as follows: apply to scalp; repeat until impoverished; watch new hair fall out.

Derek Dane, based in Leeds, has been a trichologist for decades and is one of Britain's few expert witnesses on hair. "You have about 150,000 hairs on the average head," he says. "Each hair is alive at the follicle, but once it leaves that it's dead. Each one renews itself over an average of about 28 days. Hair is a protein, keratin, which is made up of 20 amino acids and pretty indestructible. It's the strongest protein in the body, and will last for a thousand years or so in a museum."

The hair structure is simple: each strand has a cuticle made of protein, around a cortex, also made of protein, which gives the hair properties such as strength. "The cuticle is structured like the tiles on a roof, viewed upside down [so they overlap towards the tip]," Dane says. "Those 'tiles' are lifted by ultraviolet, oxygen and anything you put on your hair. When they are lifted, the atmosphere gets in, damaging the core." Water gets out, and the core becomes brittle. The disarranged "tiles" mean the hair isn't uniform and shiny.

This is why the Holy Grail of shampoos is something that seals those tiles. Makers have tried dozens of products, including a silicon-based chemical, dimethicone, which, Dane says, attaches itself to the hair surface and protects the core by closing up the cuticle.

And what about quaternium, or quat? This turns out to have the less snappy moniker of methenamine 3-chloroallylochloride, and may release formaldehyde (and cause eczema). Still, it sounds scientific. "Basically, our bodies and the earth have surplus electrons, and so are negatively charged" Dane says. "Quaternium-style compounds are positively charged, so they will stick to the surface of the hair by electrostatic forces." In the process, they leave the strands without charge, so they're less likely to repel each other, which is what can lead to flyaway hair.

Products that promise to be "pH-balanced" compensate for detergent's natural alkalinity by adding some acidity (usually citric acid).

And what about ones that "hydrate" hair? Can they work for something already dead? Yes, Dane says: "Hair easily loses moisture and becomes brittle. It does require hydrating." But not much: about 10 per cent of the weight of a well-hydrated strand is water. Almost all the rest is the keratin itself.

So does shampoo science makes any sense? "Ye-e-es," Dane says, cautiously. "But a little knowledge is a dangerous thing. The next time you're buying shampoo in the supermarket, just shut your eyes and grab whatever comes to hand." He adds that the shampoo market has the benefit at least of perhaps giving "budding young scientists the chance to work in the laboratories of these big companies".

One such budding scientist is Dr Steve Shiel, a senior scientist at Procter & Gamble's UK beauty division. When I catch up with him at a hair scientists' conference in Berlin, he is breathless with excitement. Not for them the finer points of curling tongs; Shiel's team has definitively discovered the cause of dandruff.

"It's a fungus," he explains. "It grows on everybody's head, and feeds on the natural oils that you secrete. In some people, the waste products from the fungus, called oleic acid, irritate the scalp. Normally all the skin on your body is replaced over a 28-day cycle; the fungus irritation shortens that to seven days. That means that the dying skin can't dry out enough, so it doesn't break into the invisible pieces it normally would. Instead, you get big, visible flakes."

So what will be the next weapon in the war against dandruff? "Develop something to kill the fungus," says Shiel, 35, who went to Procter & Gamble "because it's a challenge to make a significant difference to the appearance of your hair".

So what about pro-vitamin B5, then? "It's a very small molecule, which is important, because to have any benefit it has to be able to penetrate through the protective outer layers - there are five or six of them - to the core of the hair." From him, it all suddenly makes sense.

But I still haven't found out about Nutrileum. Fortunately, a spokeswoman for L'Oréal, whose Elvive shampoo claims to contain it, can help. "Nutrileum is a product that nourishes hair that is weak. It fills up gaps in the hair shaft." One suspects, though, that Nutrileum is actually called something like 5-gamma-hydroxychlorophoni-quinone, and the marketing chaps chose its new name after deciding that "kittensoftium" was overdoing it. But why emphasise this science aspect rather than photograph the results? After all, bacon adverts don't emphasise that the product contain nitrites to preserve the meat.

"We carry out tests with consumers to see whether they are happy with the wording," the L'Oréal lady says. But it's still a marketing-led emphasis, surely? "We talk to our scientists about the adverts."

So does this focus on science mean that we might soon see scientists on screen, too? "Oh, no," says the L'Oréal spokeswoman, scandalised. "We are a very aspirational product. We are fronted by beautiful women, and most of our consumers want to be like them. Would you like to look like a scientist?" She leaves no room for reply. "That's why we use celebrities. Because people like to look like that."

So just remember: when it comes to the science bit, simply leave it to someone else. What's in a name, as long as you can pronounce it?

FOLLICLES AND FOLLIES

L'Oréal Elvive £1.65

With: Nutrileum.

The claim: Nourishes, calms and smoothes. The science: Hair does require hydrating, but only about 10 per cent of the weight of a hair strand is water.

Sunsilk £1.99

With: Duo Keratins.

The claim: for hair damaged by wear and tear.

The science: hair is a protein, keratin, made up of 20 amino acids. It is virtually indestructible.

Lee Stafford poker straight shampoo £3.99

With: Extra Mega Quat*.

The claim: to silken, soften and shine.

The science: Quaternium-style compounds stick to the hair by electrostatic forces, which does reduce the problem of flyaway hair.

Pantene Pro-V £1.95

With: pro-vitamins.

The claim: moisturises and smoothes dry, frizzy, unruly hair.

The science: pro-vitamins are virtually useless until they are transformed into vitamins in the gut and in the blood. They'll do nothing on the hair.

Garnier Fructis Sleek & Shine £1.69

With: nutritive fruit micro-oils.

The claim: nourishes dry hair.

The science: citric acid is commonly added to shampoos to balance the pH of alkaline detergents.

Alberto VO5 £1.95

With: Vitasilk™.

The claim: reduces frizz and adds shine.

The science: vitamin B5 is a very small molecule that can penetrate the hair and get to the core.