Silicones: Separating The Good From The Not-So-Good

Some silicones can be quite luxurious.

Often today, more emphasis is put on what isn't in a product, rather than what is. Take silicones: hair care labels routinely tout formulas as silicone-free, but they don't instruct on why silicones have been left out, or what negative effects they may have.

Do you play it safe and go silicone-free? Or do you take a chance with a silicone-fused concoction? These are good questions, and I’m about to let you in on the info that won't fit on the conditioner bottle.

What Are Silicones?

Silicones are in tons of products that we use every day. They can be versatile tools for hair repair and they serve us well for skin barrier protection and wonderful feel modifiers. But what are silicones? Silicon is an abundant element that is found in over 90% of minerals that make up the earth’s crust. People living during the Stone Age used silica-based stones for making tools, but silicon technology was first pioneered in 3000 BCE by the ancient Egyptians, who converted sand (which is primarily silicon dioxide) into glass. Here's a timeline of silicon innovation:

1824: Silicon is identified as an element.

1850s: Henri-Etienne Saint-Claire Deville develops a method for obtaining pure silicon.

Late 1800s: Dr. Frederick Kipping begins synthesizing a number of silicon-carbon polymers that he called “silicones.”

1930s: The first commercial silicone is introduced by Corning Glass.

1940s: Silly Putty, a silicone-based toy, is accidentally developed.

1950s: Silicone compounds are applied to cosmetics for the first time with the introduction of dimethicone, a silicone-based polymer with lubricating and conditioning properties.

By the '70s, silicones were being incorporated into hair products, and now silicones can be found in over half of all new cosmetic products. Silicones are made up of a silicon and oxygen (Si/O) backbone. These backbones then have carbon methyl groups (CH3) attached to them, which round off the molecule. The length and shape of the backbone chain can vary, and this affects how thick the silicones are and can attribute heavy or light feelings to your final product.

Silicones In Skincare Products

Now that you know what silicones are, we'll dig into why cosmetic companies use them. Silicones behave quite differently than their hydrocarbon cousins (oils). Firstly, they are incredibly slippery. When you feel a silicone neat (i.e. not mixed in a formula) it has an almost Teflon or slimy feel. This slippery aspect might not be attractive on its own, but it boosts the look, feel, and spreading performance of a lotion or sunscreen, especially mineral sunscreens, where silicones are used to combat a whitening or “ghosting” effect.

Silicones are used sparingly in most skin and hair care applications, but even a small amount is one of the big differences between a moisturizer that feels OK and something that carries a hefty price tag at Nordstrom. The number one way people in my industry describe silicones is that they add a feeling of luxury--and I couldn't agree more. A lightweight dimethicone or cyclomethicone (which I'll explain soon) can make a heavy sunscreen feel lighter than air.

Silicones In Hair Products

In terms of health and safety, there are no issues with using silicones, but some silicones can be very hydrophobic or water-hating. This attribute helps to reduce the porosity of the hair, which makes it less likely to absorb humidity and therefore smoother and straighter. This aspect also helps to condition and reduce moisture loss from within the cuticle of your hair. Here's where the "bad rap" comes in: some silicones can feel heavy and be difficult to wash out. Silicone “buildup” is a newer term to describe this effect.

Which Silicones Should I Use/Avoid?

For those of you wishing to avoid buildup-causing silicones, here are a few to look for and/or avoid depending on your needs.

Cyclomethicone is one of the most commonly used silicones in hair care. It evaporates and won't leave buildup on your hair. It gives a silky, smooth feel and leaves wet hair with incredible slip. You'll find cyclomethicone in both leave-in and rinse-off products.

Dimethicone copolyol is actually a water-soluble silicone. It is lightweight and provides very little buildup. It is often used in conditioning shampoos, but it can be expensive and will increase the cost of whatever product it's added to.

Amodimethicones (or silicones that have "amo," "amine," or "amino" in their name) are modified to stick to your hair better. While they condition well, they can be challenging to remove. Amodimethicones are common in leave-in conditioners and are well suited for people with thick, tight curls or “unruly” hair.

Dimethicone is the most common and least expensive silicone. It's great for conditioning and adding shine, but it can be difficult to remove. Additionally, this heavy coating can make hair feel heavy.

So, bottom line: not all silicones are bad news. But, as with all things, silicone products should be used in moderation based on how good or bad they react with your hair.

Has anyone gone silicone-free? What questions do you have about silicones that I may not have answered in this article? Fire away!