One of the most common ingredients used to provide heat protection properties is silicone. But before you call up your curlfriends to start a petition to ban me from natural hair sites worldwide, let me explain why silicones may be your best friend when it comes to combating the effects of heat on your hair. Silicones or polysiloxanes (as my nerdy friends in lab coats call it) are made from combining silicon (Si), the 14 element of the periodic table, with oxygen, hydrogen, carbon and sometimes other materials. When silicon is combined with these organic substances, it becomes a heat-fighting machine due to its ability to remain strong and flexible when exposed to a vast range of temperatures. This attribute allows silicones to not break down when exposed to high temperatures, creating a strong barrier between the cuticle layer of the hair and the ultimate moisture killer: heat.
The barrier that silicones create also serves as an insulator of moisture for hair. Essentially, silicones are locking moisture in, while slowing down the penetration of heat to the hair. It may sound a bit counterintuitive, but direct heat is what increases the damage of the cuticle layer and weakens the hair. This protective barrier shields the cuticle from direct exposure, without preventing heat from penetrating completely, which mitigates the amount of damage the hair is exposed to while still allowing enough heat in to achieve the straightening effects.
I understand that silicones have garnered a bad reputation for causing buildup on the hair. However, in this case, it is the buildup that is saving your hair. A number of silicones such as dimethicone and amodimethicone have an amazing ability to substantively adhere to hair fibers to reduce heat damage and retain moisture inside the hair for a long period of time. Other silicones that are commonly found in heat protection serums and sprays, such as cyclomethicone, are extremely volatile, meaning it evaporates very easily and quickly. Cyclomethicone is often used at a very high percentage in formulas because it acts more as a delivery mechanism and temporary heat barrier, rather than thicker, more substantive silicones that adhere to the hair for long periods of time. Products that have a high level of ingredients that start with “cyclo” and end with “cone” are most likely formulated to not cause unmanageable buildup on the hair.
Thinking about natural oils? They have a number of similar heat protection properties that silicones have. Like silicones, the hydrophobicity (resistance to water) of oil allows it the ability to create a thick barrier on the cuticle layer of the hair without an abundance of penetration into the hair. It is very hard for most oils to penetrate the cuticle layer of the hair because the molecular structure is often too big to fit through the very small openings on the surface. Therefore, oils behave very similarly to silicones by creating protective barriers from bad things like heat. This is why we often cook with ingredients like olive oil. Oil has a natural ability to withstand high amounts of heat, in turn, preserving the moisture content of our food so that it does not dry out in that hot frying pan. Some oils can remain in tact at extremely high temperatures, but they are often the heavier oils that can weigh the hair down. This is why formulating chemists will combine synthetic ingredients like silicones with the natural goodness of oils to provide an improved customer experience when using the product.
Water-based heat protectants
There are also water-based heat protection products that commonly utilize the film-forming powers of polymers such as polyquaterniums and acrylate copolymers, just to name a few. Polymers have some resistive properties to heat and are great at retaining moisture in the hair by creating a tight forming film around the surface of the hair. Polymers are great for preventing a variety of types of damage, as well as improving wet combability and softness of the hair. Although some polymers are designed to withstand high temperatures, most studies show that silicones will usually beat out a polymer when it comes to remaining functional at high temperatures.
Quite often companies sell products as a system of products that work together to produce the desired effects. In systems like these, there are heat-fighting ingredients in each product that are then layered on the hair in stages to create your shield of protection. Scientifically this may be true. However, the naughty secret is that there is usually one core product that provides most of the heat protection benefits. If you are consistently using a lot of heat on your hair, then you will probably benefit the most from utilizing a system that contains heat protection ingredients in each product. However, if you are the type of curly girl who goes straight only few times a year, then my suggestion is to use a great deep conditioning product before a straightening treatment, as well a great heat protection product that is applied on the hair right before heat is directly applied.
Follow Sister Scientist here:
Facebook, Instagram, and Twitter.