What is a Humectant?
Humectants have one job…to moisturize hair. Humectants are ingredients that are capable of attracting water molecules from their surroundings (the air in the environment), while simultaneously keeping the surface applied (can either be the hair or the skin) moisturized.
Why do we need Humectants?
To answer this question we have to go deep down into the basic chemistry of hair.
The secretion glands of the scalp secrete a waxy substance called Sebum. Sebum serves as a nice barrier of protection for the scalp and hair, from external damage (liking drying out from seasonal changes). As well as it acts as your perfect ideal conditioner. Since the structure of our hair strand curls, this really slows down the sebum’s ability to spread all the way down to the ends of our hair. This means most of our strands will become dry and susceptible to breakage since the sebum is still trying to make its way down the individual curl strands.
This is why we need humectants and other products to help moisturize our hair, and most importantly help us lock-in that newfound moisture for longer periods of time. Curly hair is naturally drier than straight hair because sebum can easily travel down straight strands much more quickly than it can get down the spirals of textured hair. Humectants also help increase our hair’s natural moisture retention levels.
Humectants are also used in hair products because of their ability to volumize the hair by attracting moisture and binding it, which causes the hair shaft to expand.
How do humectants work?
Humectants are able to draw moisture from the environment and also draw moisture from the actual hair products applied to the hair. Humectants are extremely hydrophilic (water-loving) molecules.
Humidity is the amount of water vapor in the atmosphere. Since dry hair contains very minimal water, when exposed to high humidity environments the hair eventually becomes saturated with the water molecules from the air. Textured hair (all hair that is not naturally straight) is far more susceptible to this since it is much more porous. To understand this part I have to break down a little more chemistry.
So, Chemist Tonya Mckay, notes that when dealing with humectants we must consider the Theory of Thermodynamics. This is a big fancy word for the study of energy. Now as we all learned in seventh-grade science, energy comes in many forms. Nature has a way of making sure all energy always reaches a point of equilibrium or balance.
Molecules that are in a highly concentrated area will always move to lower concentrated areas. This is called diffusion. So hair is no different. The same laws of molecule diffusion still apply.
When used properly, what can humectants offer us?
When used at the right times, humectants can help make hair softer and have more body. It protects hair from drying out and experiencing breakage. Humectants also help increase the hair’s elasticity.
How can humectants harm my hair?
When used at the wrong times of the year (for example high humidity or low humidity), humectants can absorb too much moisture from the environment causing the hair shaft to expand (hello volume, and hello frizz). Humectants, when used in low humidity, can cause frizz by trying to pull moisture from the environment where there is none. If the humectants are unable to pull in more moisture, hair begins to dry out and become brittle.
What times of the year can I expect my humectants to work best?
If you live in a part of the world that experiences low humidity (cold, dry air, similar to autumn/winter months) this means that the air is colder and will be much drier. This more sounds like a typical birthday of mine since my birthday is New Year’s Day, as we all know January in NYC is not the greatest for hair days.
If this sounds like your kind of environment, there isn’t going to be enough moisture in the air around you for the humectants can absorb. This will lead to minimal frizzing. The negative side to humectants is that they can also remove water from your hair during climates like this. That is why it is so important to use sealants to lock in that moisture and prevent even more frizzing.
If you live in a part of the world that experiences high humidity (lots of moisture in the air, hot climate, similar to summer months) Humectants can actually end up absorbing too much moisture, which will expand the hair cuticle and cause frizz.
When in doubt, when thinking of using humectants, always remember climate and weather are big factors:
If the dew point is 60 degrees Fahrenheit or above, try using anti-humectants(also known as emollients).
If the dew point is between 35- 50 degrees Fahrenheit, use humectants but make sure to use an emollient to seal!
What is Dew Point?
Dew point is associated with relative humidity. Essentially, the higher the dew point is, the more moisture there is in the air. So logically, the lower the dew point, the less moisture is in the air.
Ideal Dew Point for Humectant use: 35-50 degrees Fahrenheit
Ideal Dew Point for Anti-Humectant use: 60 degrees Fahrenheit and above
What is an emollient?
Natural emollients come in the form of an oil or butter. Emollients are ingredients that help seal moisture into the hair by smoothing the scales of the hair cuticle down. This results in moisture being locked into the hair strand, and a nice shine since light molecules are reflected off of tightly seal scales of the strand.
What are some natural emollients?
- Coconut oil
- Castor oil
- Grapeseed oil
- Jojoba oil
- Olive oil
- Argan oil
- Shea Butter
- Sunflower oil
- Avocado oil
- Mango Butter
- Jojoba Butter
- Broccoli oil (Special tip! SOTC with broccoli oil since it mimics properties of silicones, it will lock moisture in!)
What are anti-humectants?
Anti-humectants(also known as emollients) are essentially products with moisture blockers to prevent the hair from trying to absorb moisture from the environment. This, in turn, minimizes frizzing.
What anti-humectants should I look for?
- Shea butter (raw/unrefined)
- Organic Beeswax (This ingredient is avoided if you follow the curly girl method)
- Hydrogenated Castor oil
- Mango butter
- Palm oil
- Extra virgin olive oil
What are some of the more powerful humectants to look out for?
Some examples of the more powerful humectants you can find in your products include:
- Sodium PCA
- Sodium Lactate
* Expert Tip: Avoid these humectants when the humidity levels are too high or too low. Instead, try looking for these less powerful humectants:
- Hydrolyzed Silk Protein
Does the placement of the humectant on the ingredient label matter?
Absolutely! Always remember the first five ingredients on any label make up roughly 80% of the product. Therefore, if the humectant listed (for example Glycerin) is listed within the first five ingredients, it means the product is largely made up of humectants, so if you are trying to avoid humectants put the bottle down!
If the placement of the humectant is below the first five ingredients on a label it will have much less effect on the hair.
Also remember, milder humectants are often used in conjunction with a stronger one in a formula to create a sort of balance.
Well formulated products will contain both humectants to attract the moisture and emollients to lock in that moisture:
- Humectants = attract moisture
- Emollients= lock in moisture
So, make sure to find a product that has a good balance of vegetable oils and butter!
List of All Humectants:
- Glycerin (includes vegetable glycerin)
- Panthenol (Pro Vitamin B5)
- Propylene Glycol (Has been known to cause irritation and contact dermatitis in some people)
- Ethylene/Diethylene Glycol – Causes irritation and contact dermatitis in some)
- PEG Compounds (Example polyethylene glycol)- May possibly contain the toxic byproduct dioxane)
Biological Origin Humectants:
- Sodium PCA
- Hyaluronic Acid
- Sugars and Modified Sugars
- Polyglyceryl Sorbitol
- Hydrolyzed Proteins
- PEG-x (example polyethylene glycol)
- Silicon Polyols
- 1,2,6 Hexanetriol
- Butylene Glycol
- Triethylene Glycol
- Sodium PCA
- Propylene Glycol
- Hexylene Glycol
- Dipropylene Glycol
- Potassium PCA
- Hydrolyzed Elastin
- Agave Nectar
Updated January 22, 2021