1. Hair and nails are both mainly made of a type of protein called keratin, which contains a lot of an amino acid called cysteine. All this cysteine is one of the main reasons why keratin is so strong. There is also a lot of keratin in skin.
2. Cysteine is also why you can perm or straighten hair chemically – the chemical reactions that happen are called redox reactions. Cysteine is one of the things that give hair its shape.
3. Hair dryers set hair by changing the hydrogen bonds which also help give hair its shape. Unfortunately, water is also good at forming hydrogen bonds, so humidity quickly messes up your hard work!
4. Hair is technically dead – the only bit that’s living is in your scalp. That’s why “feeding” your hair vitamins and amino acids generally won’t work.
5. Most shampoos are slightly acidic – low pH products help close the hair cuticle and make your hair smooth, shiny and less prone to damage.
6. Trichotillomania is the name of the disorder where you pull out your hair/eyelashes/eyebrows compulsively. It’s a lot more common in girls than boys, and is usually stress-related.
7. Hair grows at a rate of around 1.25 cm or 0.5 inch each month. Bum-length hair is around 7 years old!
8. Different textures of hair have different cross section shapes – if you look at straight hair under a microscope, it’s round, but curly hair is a flat oval.
9. You know how on short-haired guys you can tell which way the hair spirals from the centre? A study of 50 gay men found that 23% had a counterclockwise spiral (tracing from the centre outwards), while only 8% of the total population has a counterclockwise whorl. Put that in your gaydar!
10. One of the major causes of dandruff is a fungus called Malassezia globosa. Many anti-dandruff shampoos act by killing the fungus.