Skim through

What it does: deodorant, emollient, conditioning, moisturizer/humectant 

The science

It’s a multi-tasking ingredient that gives the skin and hair a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives. Caprylyl glycol is a humectant, meaning it hydrates by attracting and retaining water. Caprylyl glycol is amphiphilic, a chemical with hydrophilic (water-loving) and lipophilic (fat-loving) parts. The hydrophilic portions interact with water, while the lipophilic portions interact with fat. This reduces the surface tension between water and oil, making it ideal for emulsifying formulas with both ingredients. The result is a product with great spread. 

The compound also exhibits moderate antibacterial activity, which reduces any risk of developing a skin infection.

Benefits for your hair

Promotes hydration

Due to its hydrating and conditioning properties, caprylyl glycol softens the hair, making it easier to detangle, reducing breakage.

TLDR 

Caprylyl glycol is a great conditioning and hydrating agent that helps in making the hair softer and easier to detangle. It is also a preservative that helps to prolong the shelf life of products.