Frizz and humidity: how to protect your hair

Your hair looks neatly styled, then the first drops of rain bring out the flyaways: humidity can change the way your hair looks. To help keep frizz in check, combine gentle handling, the right drying technique and a treatment with instructions that fit your routine.

Before choosing an anti-humidity hair spray, check whether it needs to be used with a hairdryer. A product designed for blow-drying will not necessarily suit an air-drying routine.

To help you build your routine, our guide to pH and hair care explains how to choose hair care products.

Why does hair swell in humid weather?

Hair absorbs water as humidity levels rise. This can cause the hair fibre to swell and alter its mechanical properties. Water also affects the hydrogen bonds in keratin, the protein that gives hair its structure, helping to explain why a shape created through styling is temporary. These processes are described in Clarence R. Robbins’ scientific book on the physical and chemical properties of hair [1].

In practical terms, some strands bend or separate from the rest more than usual. Your style looks less defined, and your hair may gain volume. It does not necessarily mean your blow-dry went wrong.

Tell humidity-related frizz apart from other causes

Notice when frizz appears: as you dry your hair, or mainly once you step outside? If it happens during drying, friction, detangling and your styling technique also deserve attention. Rough or brittle lengths may need a tailored routine, particularly after chemical treatments. Read our article on how hair colouring affects your hair.

Helpful steps before heading out

Gently squeeze out water and detangle without rubbing

After washing, gently squeeze the lengths with a towel rather than rubbing them. Detangle carefully, starting at the ends and gradually working upwards. Work in sections so you do not pull on a large knot.

Match your drying technique to your chosen style

For a blow-dry, divide your hair into manageable sections. Keep the hairdryer moving and brush gently through the lengths without pulling too hard. Check the sections at the nape of your neck, which are easy to miss.

To preserve natural curls, avoid dry brushing, which breaks up curl clumps. Choose a treatment that works with your drying method: the brushing routine required by a heat-activated mist is not interchangeable with a curl-definition routine.

Protect your style outdoors

A hood or umbrella helps limit direct contact with rain. Loosely tying your hair back can also help keep the lengths together. Once outside, avoid constantly touching or brushing your hair again: this can make it look more tousled, especially if you have curls.

Which leave-in treatment should you choose for frizz?

The American Academy of Dermatology states that a leave-in conditioner can reduce frizz, static and flyaways. However, this general advice does not quantify resistance to humidity or validate any particular mist.

When choosing a product, check four things: whether it explicitly mentions humidity, whether it should be applied to damp or dry hair, whether it requires heat, and whether it can be used with other styling products. Heat protection is a separate function: our article on heat protectants explores this in more detail.

What Perfecting Hair Mist claims to do

According to its official product page, Perfecting Hair Mist coats hair fibres in a lightweight protective veil. The manufacturer claims that it helps with frizz, the effects of humidity and heat from styling tools, while adding shine. These benefits are manufacturer claims, not independently validated clinical findings.

How to apply the mist according to its official instructions

A hairdryer is essential for this mist: the manufacturer specifies that it is activated only by the heat of a hairdryer.

1. Wash your hair and gently squeeze out excess water with a towel.
2. Unlock the bottle by gently pushing the small round “On/Off” button beneath the applicator sideways.
3. Spray generously onto damp hair, section by section.
4. Distribute evenly with your fingers or a detangling brush.
5. Blow-dry on a hot setting while brushing gently.

For the best results, the product page recommends using no other styling products before drying. It advises leaving time between applications according to your preferences and hair type, rather than automatically reapplying after every wash.

Persistent frizz: what to check

FAQ: anti-humidity spray and your everyday routine

Is it suitable for curly hair?

The product page does not provide a specific method for natural curls. It instructs you to blow-dry on a hot setting while brushing gently, so take this method into account if you want to preserve your curl definition.

Does it make fine hair greasy?

The manufacturer describes the formula as lightweight, with no greasy residue or heaviness. The product page does not provide separate results for fine hair.

How long does the effect last?

The manufacturer claims protection against humidity “from morning to evening”. The product page does not specify a duration in hours or any test conditions.

Can you use a straightener or curling iron afterwards?

Yes. The product page allows the use of a straightener or curling iron after blow-drying on a hot setting. This step is optional.

Sources

• [1] Clarence R. Robbins, Chemical and Physical Behavior of Human Hair, 5th edition, Springer, 2012. Reference on water absorption and the properties of the hair fibre. DOI: 10.1007/978-3-642-25611-0.
• American Academy of Dermatology: tips for using leave-in conditioner.
• My SOS Beauty: the official product page for Perfecting Hair Mist, linked above, for the stated benefits and instructions for use.