Oily Scalp: Part 1, Some Facts

Everybody knows what oily scalp is, right? It's a scalp that produces lots of oil. Hair that gets greasy quickly. This short series will cover what oily scalp is, why it happens, and how to manage it. Stick around for parts 2 and 3, there will be some familiar ideas and some unconventional ones.

There are a few things that contribute to the perception of an oily scalp and oily hair.

Let's cover what "oily" means, when it can be a cosmetic or a skin-health problem, and some ways to manage cosmetically and for skin-health. This not-so-hair-focused part is going to explain a lot about the cosmetic and health aspects of this issue.

Part 1

"Oily" is actually a chemical analysis you do with your eyes and hands. If you look at your nose and it's shiny - that's actually a chemical assessment!

Oily skin feels slick-greasy, it looks shiny. On your scalp, your hair gets that greasy-wet-clingy look and sticks together at the roots. But did you know that happens because there are enough liquid-at-skin-temperature oils in the mix so you feel the slickness? The more fluid (and slippery) an oil is, the more greasy it seems in hair and skin.

Sebum (skin oil) - the extremely variable "recipe."  Our sebum is made of many different components. Some are liquid at room temperature or skin-temperature. Some are solid at those temperatures. And for different people, people of different ages, under different weather conditions or climates, depending on your genetics and skin condition, the proportions of those components can change.

This little pie chart shows a "typical" breakdown of the components of sebum. What I really want you to notice is that there is a lot of some components, and just a little of others. Most of the lipid (oil-components) shown are liquid/fluid on your skin. But the ceramides and cholesterol and some of the wax esters are not. (The gray and the reds).

The concept of whether something is fluid or solid at room temperature or skin temperature is all about its melting point.

For a visual aid, let's make an oil blend in the kitchen! I made something similar in this blog post. We have the solid and liquid oils in the top image. The solid-at-room-temperature oils look white and chunky. 

The melted-and-cooled oil blend is on the bottom-right, having become a soft or semisolid once all is mixed. This will "melt" on the skin, despite containing oils that have different melting points. 

Let's say your scalp and hair are always oily or greasy a day or two after washing. If that's not genetics or age-related, it may be related to your environment, or your skin condition.

And it may have to do with the current recipe of sebum on your scalp.

Am I making this more confusing than necessary? 

To me, this explains a lot of what happens in reality. Oily scalps are not the same every single day. Some of us have very different levels of oiliness in different seasons (allergy season, dry season, humid season). That happens for a reason.

Some of us have "oilier" scalps at age 20 than we will at age 35, even if our actual oil production doesn't change much by volume. What's up with that? 

This - this is what's up with that. Sebum "recipes" change a lot.

If you irritate your scalp and it becomes oily or dry or flaky when it's usually not - surprise! Your sebum recipe was changed by the inflammation.

In Part 2, we'll look at age, gender/hormones, climate and weather and how that influences how oily your scalp is.