'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? I query the Internet with some of the other phrases a that light skimming of hair products will uncover.
Ever heard of Nutrileum? Quaternium? Nutri-ceramides? 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 combined shampoo and conditioner.
Previously, the chemicals required for each were antagonistic, like lemon and milk, and were sold in separate bottles. P&G found a way to combine them, so was born Wash'n'Go.
The annual British haircare products business is worth £1,6-billion (about R18-billion), with £352-million (about R3,9-billion) spent on shampoo alone in 2003. A further £218-million (about R2,4-billion) was spent on conditioner. The sums exceed spending on any other part of our bodies.
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'Oreal.
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: "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'Oreal is selling us, but nobody seems to know, including L'Oreal's website and its spokesperson, who tells me that "it's meant to indicate that it's nutrition, for the hair", but remains silent when asked why something 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 (ASA) ticked off L'Oreal for suggesting that ceramide - "the hair's natural strengthener" - was what made your hair strong. Yet the ASA rejected a similar complaint over L'Oreal's claims that ceramide-R in its shampoos could strengthen hair, even though test results submitted by the company used 10 times the concentration found in the product.
When the British 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 results of 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 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, made up of 20 amino acids, and pretty indestructible.
"It's the strongest protein in the body and will last for 1 000 years or so in a museum." The hair structure is simple: each strand has a cuticle 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 three-chloroallylochloride, and may release formaldehyde and cause eczema. "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 (tsually 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 percent of the weight of a well-hydrated strand is water. Almost all the rest is the keratin. - The Independent