Dehydrated hair: causes, care, and prevention
Proper hydration is essential for maintaining soft, shiny, and healthy hair. Often underestimated, hydration plays a crucial role in preventing dryness, maintaining softness, and strengthening the hair’s resilience. Discover how to incorporate hydration into your hair routine with suitable care products, simple daily actions, and proper protection against external aggressions.
Updated on , validated by our team of René Furterer experts.
What is dehydrated hair?
Dehydrated hair lacks hydration, either due to an insufficient amount of sebum on the scalp or excessive exposure to drying external factors. Unlike dry hair, which is usually a permanent condition, dehydration can affect all hair types and is often temporary.
Signs and symptoms of dehydrated hair
- Rough texture and dull appearance: dehydrated hair loses its natural shine and can feel coarse to the touch. It lacks flexibility and softness, unlike well-hydrated hair.
- Brittle and fragile hair: a lack of hydration can make the hair more prone to breakage during styling or brushing.
- Difficulties detangling: hair that lacks hydration is prone to knots and is difficult to detangle, which can lead to hair loss when brushing.
- Static electricity: it can be prone to static electricity, especially in dry environments, making styling difficult and messy.
- Split ends and open tips: the ends of dehydrated hair often split, indicating that its cuticle has been damaged and the hair itself is in poor condition.
Differentiating dry hair from dehydrated hair
The terms “dry hair” and “dehydrated hair” are often confused. However, they refer to two different hair conditions that require specific care.
Recognising dry hair
Dry hair is characterised by a natural deficiency in sebum, the oily substance produced by the sebaceous glands in the scalp. This can be caused by genetic factors, hormonal changes, or simply by the nature of the hair itself.
Certain signs may indicate that your hair is dry:
- A lack of shine and radiance: dry hair does not reflect light well due to the lack of oil, which helps smooth the cuticle and gives it a healthy appearance.
- A rough texture: with insufficient sebum, hair can appear coarse and difficult to style.
- Itching and dandruff: a dry scalp may eventually be accompanied by itching and dandruff due to a lack of hydration. Regularly and properly hydrating the scalp is essential to prevent these issues.
- Fragility: dry hair is more prone to breakage due to its lack of elasticity.
Dehydrated or dry hair: understanding the differences
Unlike dry hair, dehydrated hair is not necessarily caused by an insufficient sebum production. Dehydration is often caused by external factors such as wind, heated styling tools, chemical treatments or an unsuitable haircare routine. Understanding the differences will help you choose the right products and care routines for your hair type, whether dry or dehydrated, to restore its health and beauty.
Not sure if you have dry or dehydrated hair? Here are some signs to differentiate them.
- While dehydration can be corrected with proper care, dry hair often requires ongoing treatment.
- Hair lacking hydration is more reactive to climate changes, such as dryness in winter and sun exposure in summer, unlike dry hair.
- Although both feel coarse, dehydrated hair usually returns to a normal texture after a hydrating treatment, whereas dry hair remains coarse naturally
How does moisture diffuse into the hair fibre?
Hair is composed of multiple layers, including the cuticle (outer layer), the cortex (middle layer) and the medulla (innermost layer). The cuticle is a layer of small scales which open and close depending on hydration and the treatments applied. When they are closed, they protect the hair and help retain moisture within the hair fibre.
Capillarity is a physical phenomenon that helps distribute moisture along the hair fibre. Thanks to this principle, hair can absorb water and diffuse it into the cortex, where it is stored to maintain elasticity and flexibility. Curly or kinky hair, often more porous, particularly benefits from this phenomenon to retain hydration, although this also makes it more vulnerable to moisture loss.
Impact of chemicals and natural elements on hair hydration
The effects of chemicals on hydration
Using chemicals like hair dye, relaxers, and keratin treatments can significantly reduce hair hydration. These products weaken the protective lipid layer leading to hydration loss. They also make the hair more porous, allowing moisture to escape more easily, which often results in chronic dehydration.
Good to know: chemical dehydration happens when harsh products or treatments (like hair dyes and relaxers) strip water from the hair fibre. This process affects the internal structure of the hair, weakens the bonds between water molecules, and reduces its ability to retain moisture. When its fibre is damaged in this way, it becomes difficult for the hair to maintain its flexibility and resistance to external aggression.
The influence of the sun, wind and friction
Natural elements also affect the health of the hair. Prolonged sun exposure can weaken the keratin, render it less capable of retaining water, and more vulnerable to damage. The wind dehydrates the hair by quickly dissipating its natural moisture and causing tangles that require aggressive brushing, risking damage. Lastly, frequent friction against rough fabric, such as scarves or hats, can also damage the cuticle and worsen hair hydration.
Causes of hair dehydration
Various internal and external factors can cause dehydration by reducing the hair’s ability to retain natural moisture.
Intrinsic factors
- Genetic
Our genetics determine sebum production, hair texture, and porosity. People with naturally dry or porous hair are more prone to it getting dehydrated. - Age
With age, sebum production decreases, making hair less lubricated and more susceptible to dehydration. Ageing hair also undergoes structural changes that impair its ability to retain water.
External aggressions
- Use of chemicals products
Chemical products, such as hair dyes and relaxers, can degrade the hair’s protective barrier. These processes increase its porosity and facilitate moisture loss, leading to continuous dehydration. - The sun
Prolonged sun exposure degrades keratin and damages the hair cuticle. Over time, this reduces the its ability to retain moisture and increases its porosity. - Pollution
Pollutant particles accumulate on the hair and scalp, clogging the pores and reducing sebum production. They also cause oxidation, which further weakens the hair structure. - Temperature variations
Temperature changes, such as cold, dry air in winter and intense heat in summer, reduce the humidity in the air and dry out the hair. - Wind and friction
Wind accelerates moisture loss, while regular friction against rough fabrics causes mechanical abrasion that damages the cuticle and exacerbates dehydration.
Prevention of hair dehydration
Water is an essential ingredient in masks and moisturisers for a reason. It helps keep the hair flexible and strong, while regulating the scalp’s natural oil production, promoting a healthy, balanced hydration.
Preventing hair dehydration helps maintain its health, shine, and flexibility. Here are some tips to prevent dehydration over time.
5 tips to prevent hair dehydration
- Drink plenty of water every day. Proper hydration benefits your overall health and helps keep your hair well-hydrated.
- Avoid washing your hair too often and opt for hydrating shampoos, conditioners, and masks with gentle formulas containing aloe vera, glycerin, silk proteins, or natural oils (argan, jojoba, coconut).
- Limit your use of hairdryers, straighteners, or curling irons as they dry out the hair. Opt for lower temperatures to minimize damage and always use a thermal protector.
- Protect your hair from the sun, wind, and pollution, and consider using products with UV filters if you spend time outdoors.
- Wear a bonnet or use a satin pillowcase to reduce friction overnight and help retain your hair’s hydration.
Ingredients to avoid to protect your hair’s hydration
Some common ingredients in hair products can contribute to dehydration, such as sulfates and silicones.
Sulfates, often used as foaming agents, are known for stripping rid of excess sebum. However, they can be too harsh and remove the hair’s natural oils, making it drier and more fragile. Opt for sulfate-free shampoos, which cleanse gently without damaging the hair’s hydrolipidic film.
Silicones form a film around the hair fibre, providing temporary shine. However, by blocking moisture penetration, they can cause long-term dehydration. Favour silicone-free products, so your hair can fully absorb moisturising treatments and regain its natural flexibility.
Find a hair routine suited to your hair
- To deeply nourish and hydrate your hair, add a hydrating mask to your routine at least once a week.
- Gently pat your hair with a towel to dry it, or let it air dry. Avoid rubbing, as it can cause friction and breakage.
- To detangle your hair without damaging it, use a wide-tooth comb when it is damp, starting at the ends and working your way up to the roots to avoid pulling and breaking strands.
Nourishment and hydration : an essential duo for healthy hair
Hydration and nourishment are two complementary concepts. Hydration provides water to the hair to maintain its flexibility and elasticity, while nourishment supplies essential oils and lipids that help nourish and strengthen the hair fibre. Hair needs regular hydration to compensate for water-loss caused by external factors, while nourishment helps lock in this hydration and protect it from breakage and dryness.
How to rehydrate dehydrated hair
Rehydrating dehydrated hair is important to restore its health, shine, and flexibility. On a daily basis, alternate between hydrating and nourishing products.
If your hair is very dry or damaged, it may need more frequent nourishing treatments. Observe how your it responds to products and adjust your routine accordingly. Do not hesitate to ask your hairdresser for a precise diagnosis and a customised routine to care for and hydrate your hair.
Curly hair: hydrate and define
Curly hair is naturally drier and requires hydrating treatments to maintain its flexibility and definition.
- Choose a sulfate-free shampoo enriched with hydrating ingredients, such as aloe vera, glycerin, and argan oil. These products gently cleanse without weighing down the curls and help maintain natural hydration.
- Apply a hydrating mask at least once a week. Curly hair benefits from masks containing oils and proteins to redefine the curls and reduce frizz.
- Opt for styling techniques such as twist out or braid out to define your curls while minimizing dehydration.
Kinky hair: intense nourishment
Kinky hair is particularly dry and fragile and needs ultra-hydrating and nourishing treatments.
- Use deeply hydrating, sulfate-free, and enriched with oils, shampoo and conditioner. These products provide hydration without damaging the naturally drier kinky hair.
- Incorporate a hydrating and nourishing mask into your routine every week. Kinky hair especially benefits from masks rich in plant oils and butters to reinforce its fibre and reduce breakage.
- Opt for protective hairstyles such as bantu knots, twists, or braids, which help retain moisture and protect kinky hair from dehydration.
Dehydrated coloured hair: protect and hydrate
Dehydrated coloured hair requires specific care to maintain its colour while restoring hydration.
- Choose shampoos designed for coloured hair that contain hydrating ingredients. These products help maintain the colour while providing hydration.
- Use a hydrating and repairing mask once a week to strengthen hair weakened by colouring, and restore the hair fibre.
- Limit your use of heated tools as much as possible and apply a thermal protector to preserve coloured hair’s hydration, which can be sensitive to heat.
