Latest Fact Sheet

Season 3, Ep 2 - Shampoo

· Hair is made up of two layers – the cuticle on the outside looks like roof tiles and protects the inside of the hair. The cortex is the inside of the hair and is responsible for the colour and texture of the hair. Some hairs also have a third layer in the very centre (the medulla) but scientists haven’t yet established its purpose or why it’s only found in some hairs.

· Hair care and styling products only affect the cuticle of the hair.

· Hair is only alive when it is growing at the follicle. As soon as it moves above your scalp it dies so once it’s damaged, the only way to fix things is to cut it.

· People with different hair colours have different amounts of hair. Blondes have 140,000 hairs on average while brunettes have 110,000 hairs and people with black hair have around 108,000 hairs. Redheads have the lowest number of hairs with only 80,000 on average.

· The central ingredient in shampoos is a surfactant. These molecules have two ends – one is attracted to oil and grabs hold of the dirt and grease in your hair. The other is attracted to water so when we rinse, the oil, grease and surfactants all get washed away.

· As well as shampoos, surfactants are found in soaps, dishwashing liquid and washing powder.

· 1,4-Dioxane can be found in small amounts in some shampoos. The USA’s Campaign for Safe Cosmetics tested some shampoos, soaps and moisturisers for dioxane last year. According to ERMA you would need to use the product with the highest concentration of dioxane more than 1000 times a day to encounter any risk.

· It is worth using a shampoo formulated for your hair type – different shampoos have different levels of surfactants and conditioning ingredients.

· Ingredients in conditioners like silicones and quats work by attaching to the hair and filling in any grooves, making the hair feel smooth and reflect light. These ingredients mimic sebum, the oil produced naturally by our scalp.

· Despite what you may believe, it doesn’t really matter how long you leave conditioner on your hair – the ingredients coat the hair very quickly.

· Dandruff is probably caused by a naturally occurring yeast that exists on everyone’s scalp. The cycle of hair growth has three phases – a growth phase, a transition phase when the hair stops growing and a resting phase when the hair falls out.

· The amount of time the hair follicle spends in each phase differs from person to person – the growth phase tends to last for up to five years, the transition phases lasts around two weeks and the transition phase lasts around three months.

· Balding (pattern hair loss) is the most common type of hair loss and affects 50% of the population by the age of 50.

· So far only two treatments of treatment have been shown to help with balding. Finasteride and Minoxidil can prevent hairs from falling out and delay balding. However, they aren’t very successful when it comes to making hair grow back on heads that are already bald and they only work as long as they continue to be used.

· In the future, hair cloning and gene therapy may be used to treat hair loss but these are years, if not decades away