Have you ever wondered why your straight or wavy hair suddenly gets curly when wet? The texture change when hair gets wet is a common phenomenon with some fascinating science behind it. Read on to understand why hair texture alters with water.
The Structure of Hair
To understand wet hair curling, we first need to cover some hair basics. Hair is made of a protein called keratin arranged in bundles.
The keratin strands are held together by:
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Disulfide bonds – Permanent, rigid bonds giving hair strength and structure
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Hydrogen bonds – Temporary, flexible bonds broken and reformed when wet and dried
Hydrogen bonds are especially key—they determine hair shape and respond dramatically to moisture.
Why Wet Hair Gets Curly
When hair gets wet, water is absorbed into the strands. The water molecules attract and bond with the keratin proteins through hydrogen bonding.
More hydrogen bonds form between keratin strands in high humidity or when hair is saturated. This causes the proteins to coil more tightly together, shortening the length of hair strands overall.
Think of it like a metal spring. When dry and straight, the coils are pulled tight. Add water, and the spring naturally contracts into a curly shape.
The more hydrogen bonds induced by water, the tighter the curl pattern becomes from this contraction.
Wet Textures Differ Between Hair Types
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Naturally curly hair gets even curlier when wet due to ample hydrogen bonding. The curls spring up and appear more defined.
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Wavy hair can temporarily become curly when saturated with water. The added hydrogen bonds enhance the underlying wave pattern.
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Straight hair doesn’t have as much natural curl tendency. But added hydrogen bonding from water can induce temporary waves or curls.
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Damaged or overprocessed hair has fewer disulfide bonds. So it relies more on (weaker) hydrogen bonds for shape. When wet, the curls amplify.
Why Wet Curls May Disappear When Dry
For hair with only a subtle natural wave or curl, the boost in hydrogen bonding from water may not last as the hair dries.
There are a few reasons the temporary wet curls can fall flat again:
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Water weight stretches out the coils before fully drying
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Fragile waves are disrupted easily without enough hold from products
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Combing or touching waves can flatten the pattern
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Humidity drops as hair dries, reducing hydrogen bonds
Using gel to set the shape and diffusing or air drying gently can help wet curls maintain their form when dry.
Tips for Managing Wet Hair Curls
Wet hair curling can be a nuisance if your goal is straight, smooth locks. But there are solutions:
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Use an anti-frizz serum or leave-in conditioner before hair dries
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Gently squeeze out excess water with a microfiber towel to reduce water weight
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Apply a smoothing cream followed by heat protectant if heat styling
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Blow dry using a paddle brush to pull hair straight while drying
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Finish with a flat iron on low heat if needed for smoothest results
If you want to enhance and maintain your wet curls as your hair dries, try these tips:
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Apply a curl defining gel or mousse to wet hair
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Diffuse hair gently with a diffuser attachment
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Air dry the rest of the way without touching or combing
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Scrunch out the crunch once 100% dry for soft definition
The Takeaway
Hair texture changes when wet because water is absorbed into the strands, forming flexible hydrogen bonds with the keratin proteins. This causes the proteins to curl more tightly together.
Hair types with an existing curl pattern see the most amplification in texture when wet. But even straight hair can exhibit temporary waves or curls in saturated conditions due to the contracting effect of hydrogen bonding.
Understanding the science behind your wet hair behavior can help you manage the results, whether you want to tame the curls or enhance them!
Causes of Wet Frizz & Webbing + How to Fix It!
FAQ
Is my hair naturally curly if it curls when wet?
Look down at your hair, and see if it’s curling into waves and ringlets. If it is, you’re probably a curly girl. Water resets your hair to its natural state. If it’s curly, you’ll be able to tell!
Why is my hair curly when wet but straight when it dries?
Why is my straight hair curly after shower?
Does wet hair make your hair curlier?