It’s time for me to gush about rosehip oil again! It’s my favourite skincare oil, and it’s my SOS beauty saviour – whenever my skin is looking dull or pimply or otherwise subpar, I give it a break from all my other treatments and just slap on rosehip oil. Today I’m focusing on one of its components: linoleic acid, also known as an omega-6 fatty acid.
What is linoleic acid?
If you remember from my soap chemistry post, all fats and oils are composed of three fatty acids (the blue sections on the right hand side), chemically bound to glycerin (the purple section on the left hand side).
Linoleic acid is one of the many fatty acids that you can attach. It’s unsaturated, which means it tends to stay liquid at lower temperatures. Other unsaturated fatty acids include oleic, alpha-linolenic, gamma-linolenic and ricinoleic acids. There are also saturated fatty acids (lauric, myristic, palmitic, stearic) which are more common in solid fats.
As you can see from the structures, the saturated fatty acids are quite straight, oleic acid is reasonably straight, while linoleic acid is a bit kinky.
What does linoleic acid do for skin?
People who are acne-prone tend to have a low percentage of linoleic acid, and a high percentage of oleic acid in their sebum (natural skin oil). It’s thought that these low linoleic acid levels is one of the things that causes acne.
In one study, rubbing 2.5% linoleic acid on the faces of people with mild acne made their microcomedones (baby pimples) smaller – fantastic news for people looking for acne relief! This is particularly helpful because the most popular acne treatments (benzoyl peroxide, antibiotics, tea tree oil) focus on killing bacteria, so this targets a completely separate part of the process, plus it can help with non-infected clogged pores as well. 0.5% linoleic acid in ethanol was also good for reversing UV-induced hyperpigmentation (aka sun spots) in lab animals.