This article was taken from the September 2011 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
Every month wired's chemist Dr John Emsley deconstructs an everyday product. He is the author of 110 research papers and ten books, his most recent being
Nature's Building Blocks, 2nd edition (OUP).
<span class="s1">Ingredients
Minoxidil
Alcohol
Water
Glycerol
Cetyl alcohol
Citric acid
Lactic acid
Stearyl alcohol
Polysorbate 60
Butyl hydroxytoluene
SD alcohol 40-B
Propellants
Minoxidil
This compound was designed as a treatment for high blood pressure, but men who tested it reported that their hair started to regrow.
Alcohol
Also known as ethanol, it acts as a solvent for the minoxidil, which is an organic molecule and so needs an organic solvent to solubilise it.
Glycerol
A by-product of soap and biodiesel manufacture, this is also produced in the body. Here, it helps to reduce moisture loss from the scalp.
Cetyl alcohol
A saturated fatty alcohol, AKA 1-hexadecanol, that acts as an emulsifier. Cetyl alcohol keeps all of the ingredients suspended in solution.
Citric acid
This stabilises the solution's pH and is used in making the explosive hexamethylene triperoxide diamine (HMTD).
SD alcohol 40-B
This is alcohol made undrinkable by the addition of Bitrex, once listed in the Guinness Book of World Records as the bitterest substance.
Lactic acid
Present in dairy, bread and meat, it's produced in the body as a by-product of metabolising carbs. It's a vital component of healthy skin.
Propellants
Propane, butane and isobutane are used to propel Regaine from the can. Propane has three carbon atoms (C3H3) and the butanes four (C4H10).
Polysorbate 60
This has water- and oil-seeking properties and acts as an emulsifier. It is used in powdered hot-chocolate drinks to ensure smoothness.
Butylated hydroxytoluene
This is a powerful antioxidant added to ensure that the other ingredients do not ever become chemically degraded.
This article was originally published by WIRED UK
