Humectants, Humidity and Curly hair

If you have read my earlier posts, you know about humectants. So, today lets talk about their role in hair care products.


Humectants draws water from the air and hence are used in the products to increase the water retention in your hair and skin. The water retention capability of these substances comes from the hydrogen bond that they make with water molecules which results in minimum water loss due to evaporation. So, because of this water binding capability, humectants are ideal for our dry curls and keep them moisturized.

But, there are times when their effect is not so good depending on the weather condition. How humectants behave depends a lot on humidity in the air. Humidity is the amount of water vapors present in the air. So let’s see the effect of humidity on your hair. First, let’s try to understand how you can figure out how humid the air is. One way of telling the moisture content in the air is the Dew point.


According to Wiki, “Dew point is the temperature at which the water vapor in a sample of air at constant barometric pressure condenses into liquid water at the same rate at which it evaporates”. That means dew point is the temperature at which the number of water vapors molecules being formed is equal to the number of liquid water molecules being formed (Evaporation rate = condensation rate). At temperatures below the dew point, water will leave the air and condenses.

Don’t worry too much about understanding the definition of dew point. You just have to understand this, the higher the dew point, the more moisture in the air. If dew point is lower, there will be less moisture in the air. So, once you step out of the house you can make out from the dew point in your weather report how you hair will behave.

Low Humidity, dry air and low dew point 

In low humidity conditions such as cold, dry winter there is less water in the air. Hence there is not much water for the humectants to draw to your hair. So, in such conditions, humctants keep the mositure in your hair. But do not rely only on humectants to get the well moisturized hair in very low humidity condition. In extremely low humidity, there are high chances that humectant draws water from hair and release it into the air and leave it dry. From dew point perspective, if dew point is below 35°F (about 1.6°C) then there will be very less moisture in the air. But you use products which has other film-formers too. So if a product is formulated well balanced then you dont have to worry about that a product containing humectant will dry out your hair in low dew point.


High Humidity, moist air and high dew point


In high humidity conditions such as tropical region or summer, there is lots of moisture in the air. In very high humidity, humectants draws lots of water to the hair which will cause it to swell and lifts the cuticle. This makes the hair frizzy and causes tangled hair which may lead to breakage. If dew point is above 60°F (about 18°C) then you feel air is humid and sticky.


So now you understand that extreme humidity conditions can adversely affect you hair. Below thing can help you to prevent damage from extreme humidity conditions


  • Use a well moisturized conditioner that does not rely only on humectants.
  • Minimize the use of products that contain higher amount of humectants. That is products having humectants that are mentioned lower down the ingredients list.
  • Use gels or styling products that contains styling polymers which gives good curl definition in these extreme weather condition.
Now you know while shopping for hair care products just keep a note of the climate you live in and how can you make most out of humectants. Common Humectants that you see in your hair products are
Propylene glycol
Butylene Glycol
Dipropylene glycol
Hexylene Glycol
Triethylene glycol
Capryl glycol
Sodium PCA
Hyaluronic acid
Polyglyceryl sorbitol
Hydrolyzed proteins
Isoceteth-x, Isolaureth-x, Laneth-x, Laureth-x, Steareth-x

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6 thoughts on “Humectants, Humidity and Curly hair

  • Anjali Khandelwal

    My giovanni tea tree Conditioner has glycerin in it my question is should I use it in winter bcoz glycerin is humectant…does it make my hair more dry because dry air in winter …asha barrak please give your opinion and others also ..

    • Asha Barrak Post author

      Anjali, I think it should be fine to use. As you are not using glycerin alone. It is present with other ingredients in the formulation which also work as film former and also if you are using styling products containing oils and other film formers (even flax seed gel), it should be fine to use. As all these things prevent water loss from hair.

  • Manasi

    I live in Mumbai, and it is very humid here most of the year as we are really close to the sea. Could you suggest a good leave-in conditoner/ styling product available in India which can combat the humid conditions and prevent from frizz to happen. I already use a sulfate and paraben free shampoo and a silicone free conditioner


    • Asha Barrak Post author

      Hi Manasi, For leave-in you can use your regular rinse off silicone free conditioner as leave-in. In gels you can try enliven, schwarzkopf taft or giovanni gels metioned on the blog list. Make sure you are using good amount of leave-in conditioner under the gel. You can also use a little amount of oil like almond or jojoba oil too before or after the gel. You can try conditioners like Giovanni, enliven, matrix, loreal, Nyassa etc mentioned in the blog list.