Photo: Champja Illustration: Volha Ramanchuk

Here, we look at a new shampoo that fights debilitating dandruff with science.

It's easy to laugh at vintage Head & Shoulders TV commercials. They tend to follow a familiar script: hapless dolt fails at romance because of ill-timed, dandruff-induced head scratching. Wise, shiny-haired friend suggests Head & Shoulders, and voilà – social success.

These storylines weren't entirely off base. Debilitating dandruff, that constant snowfall of flaking skin, can afflict people so profoundly that "We've talked to people who will choose not to go to work on certain days. They won't go to parties," says Procter & Gamble principal scientist Rolanda Wilkerson.

And while we used to think dandruff was the result of poor hygiene or dry skin, it's actually caused by a fungus existing on all our heads, Malassezia globosa, which "feeds off the natural scalp oils," explains Wilkerson. For half the population, this occurs without incident, but for dandruff sufferers, their bodies respond to this invasive presence by speeding up skin cell turnover to protect itself, resulting in that snowy shower of dead skin.

Toronto dermatologist Dr. Julia Carroll notes that "sometimes dandruff can be confused with scalp psoriasis, a condition which peaks at 20 and again at 60" for a variety of hormonal and health reasons. Patients will shed large flakes of skin and see red scaly patches and erroneously think it's dandruff, so it's best to see a doctor for a proper diagnosis.

Dandruff can resolve itself later in life, although "it may persist into old age, (usually) in men more than women," says Carroll. It is thought that men have more active sebaceous glands and therefore produce more scalp oils.

So pity the sufferers of severe, chronic dandruff who need the strongest available anti-dandruff shampoos containing selenium sulfide. They had been consigned to a life of nostril-assaulting cleansers that quelled flakes and itch but dried their hair to straw and left them with a sulphuric fug encircling their heads.

Selenium levels are regulated by Health Canada, but users needed a shampoo that felt like shampoo, not like a punishment. "So we redesigned the technology so it's more cosmetically appealing," says Wilkerson.

Enter Procter & Gamble's research centre in Blue Ash, Ohio, a sprawling, low building in startlingly verdant suburban Cincinnati.

Here, formulas are tweaked (anywhere up to 100 iterations in a week) and then tested in all manner of ways.

In one brightly lit room, hair switches, representing 40-odd subgroups accounting for ethnicity, colour, wave, age and degrees of damage, hang in rows awaiting their turn in the water while a serene woman in a colourful dashiki lathers and rinses a switch under a running tap.

Other tests look like you've wandered into a modern art museum. A close-up "flow cell microscopy" view of shampoo bubbles travelling down a hair shaft (testing shampoo efficacy) is hypnotically soothing to watch. Thermal imaging of glowing, scarlet-topped heads is a visible reminder of the damage wrought by scratching when elevated histamine levels caused by dandruff inflame the scalp.

"In a healthy scalp your histamine levels are normal. In a dandruff or irritated or flaking scalp they are very elevated," says Wilkerson. If you are aging and have thinning hair, "scratching may further damage the hair fibre resulting in breakage," she adds.

An optimal dandruff shampoo needs to "send a lubricious signal while leaving actives behind," says Eric Johnson – scientist-speak for "Your hair should feel moisturized, while anti-dandruff ingredients remain on the scalp to do their job."

Getting the ingredients from the shampoo to disperse onto the scalp is a complicated formulation trick.

The Head & Shoulders ingredient mix for this new shampoo contains proprietary selenium sulfide technology (the brand's secret sauce, if you will) together with conditioners and a subtle masking fragrance to eradicate the distinctive smell.

The result, Head & Shoulders Clinical Solutions (from $10) feels and smells like regular shampoo and still removes more than 90 per cent of Malassezia irritants while relieving symptoms. So no one has to feel like they're living in the "before" segment of a 1970s dandruff shampoo commercial.

A version of this article appeared in the September 2017 issue with the headline, "Why S0 Flaky," p. 22.

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