Shampoo. We all use it (or should!), it is a staple in our showers and is a huge portion of the cosmetics industry. Shampoo is also a controversial product for the chemophobic, containing sodium lauryl sulfate (SLS) and “color damaging” sulfates. However, before our modern shampooing methods, people used plain old soap, water, and even clay to wash their hair. Luckily for us, cosmetic chemists have developed the formula over the past hundred years and we now have a simple product that can keep our hair clean!
- The first ingredient on shampoo ingredient lists is typically water, as it makes up ~80% of the formula. The water is essentially what creates the liquid consistency of this product and makes this formula relatively simple to make.
- Detergents or surfactants are the next primary ingredient used in shampoos. Seeing as the purpose of a shampoo is to cleanse our hair, it’s no wonder that surfactants are used in high quantities in the formula. Common surfactants include the very controversial SLS, ammonium lauryl sulfate, and sodium laureth sulfate. These surfactants work by using their anionic properties. Just as micelles work, a hydrophilic head attracts the water, while the hydrophobic tail attracts all the dirt and grime on our hair. The water then washes all the surfactant away leaving our hair clean!
Traditionally water and detergent would be enough to allow our hair to be clean, however, chemists have immensely improved this formula to create a product that is not only pleasant to use, but helps keep our hair healthy.
- Much like toothpaste and body wash, consumers like to see bubbles to know that the product is working. Hence, foaming agents are added to cleaning products like shampoo! Foaming agents can include ingredients such as cocamide MEA, lauramide DEA, and cocamidopropyl betaine.
- Next up are thickeners which give the product a nice texture and consistency and obviously, thicken up the formula.
- Something you may never have given much thought to is the color of shampoo. Typically all shampoos tend to have a milky or pearly coloring and opacifying agents are the reason for this! Opacifying agents may include glycol distearate and glycol monostearate.
- Little known fact is that shampoo actually contains conditioning agents. You’ve heard the beauty tip of only washing your hair a few times a week right? This is because the surfactants can end up being pretty damaging, so conditioning agents are included to keep your hair healthy. Conditioning ingredients include silicones like dimethicone, quaternium 80, panthenol, and the polymer guar hydroxypropyltrimonium chloride.
- If you’ve ever run out of shampoo and conditioner at the same time, teach me your ways. If you’re like every other human being your conditioner runs out before your shampoo. Lucky for us, shampoos are formulated with preservatives in order to prevent microbial growth. Sodium benzoate, DMDM hydantoin, and methylparaben are a few common preservatives used in shampoos.
- Surfactants are highly basic ingredients, so according to chemistry, in order to keep this product stable/neutral, an acid must be used in the formula. Acids/buffers can include citric acid, sodium citrate, and sodium xylene sulfonate.
- I’ve written abount these ingredients before, chelating agents are compounds that grab metal ions from our water to keep our hair and hair color in shape. You can read more about them from my post!
- Finally fragrance, this ingredient might be obvious but it can be highly beneficial for formulas that have a particularly chemical smell.
So there you have it! It was a bit of a long read, but if you think about it shampoo has a relatively simple formula. So hopefully now, the next time you read your shampoo label (we all do it) you can figure out which ingredients do what!
Any comments or questions? I’d love to hear any below!