6 Causes of Frizzy Hair, and 8 Ways to Combat It

Frizzy hair is a common complaint, often blamed on weather alone. However, frizz is less about humidity and more about the underlying structure of the hair shaft and how it interacts with its environment. Understanding the true culprits—many of which are routine habits—is the key to achieving smoother, more manageable hair. We break down the six most surprising causes of frizz and offer eight actionable strategies to lock in moisture and keep the hair cuticle flat.

What is frizz?

To understand frizz, you must first understand the structure of the hair strand. Each strand of hair is protected by an outer layer called the cuticle. The cuticle is made up of overlapping cells, similar to shingles on a roof. When the hair is healthy and moisturized, these shingles lie flat, reflecting light and making the hair appear smooth and shiny.

• The Science of Frizz: Frizz occurs when the cuticle is raised, exposing the hair's inner cortex. This lifted cuticle allows moisture from the atmosphere (humidity) to penetrate the inner hair shaft, causing the hair to swell and break its natural, smooth pattern.
• A Sign of Thirst: Frizzy hair is essentially dry hair desperately searching for moisture from its environment. The more damaged or dry the hair, the more lifted the cuticle, and the more severe the frizz.

What causes frizz?

Frizz is often a sign of damage or a lack of moisture, but the specific causes are frequently hidden in daily routines.

6 Surprising Causes of Frizzy Hair

1. Harsh Shampooing: Shampoos containing harsh sulfates (like sodium lauryl sulfate) can strip the hair of its natural oils (sebum). This over-cleansing leaves the hair extremely dry and causes the cuticle to lift, resulting in frizz.
2. Towel Drying: Vigorously rubbing your hair with a standard cotton towel creates mechanical friction. This friction roughs up the cuticle, causing immediate frizz and long-term damage that makes the hair perpetually dry.
3. Excessive Heat Styling: Frequent use of high-heat styling tools (flat irons, curling wands) without a proper heat protectant rapidly evaporates the hair's internal moisture. This thermal damage permanently lifts and chips away at the cuticle.
4. Alcohol in Hair Products: Many common hair sprays, mousses, and gels contain high concentrations of drying alcohols. These ingredients provide hold but simultaneously strip moisture from the hair, leading to a dry, crunchy texture prone to frizz.
5. Showering in Hot Water: While it feels relaxing, extremely hot water can be detrimental to your hair. It causes the cuticle to swell and open significantly, washing away protective oils and leaving the hair vulnerable to moisture loss after drying.
6. Improper Combing or Brushing: Brushing dry, coily, or curly hair with a standard brush can break up the natural curl pattern and physically tear the hair cuticle, leading to a halo of frizz. Combing should primarily be done when the hair is wet and saturated with conditioner.

Ways to tame frizz

Combating frizz requires a shift in routine, prioritizing hydration and minimizing mechanical and thermal stress.

8 Ways to Combat Frizzy Hair

1. Cool Water Rinse: Finish your shower with a quick blast of cool or lukewarm water. This helps seal the cuticle down flat, locking in moisture and conditioner, which immediately improves shine and reduces frizz.
2. Switch to Microfiber or a T-shirt: Instead of rough cotton towels, gently blot or "plop" excess water from your hair using a microfiber towel or an old cotton T-shirt. This minimizes friction and keeps the cuticle smooth.
3. Deep Conditioning Treatments: Use a moisturizing hair mask or deep conditioner at least once per week. This provides intense hydration to repair the cuticle and replenish moisture lost to environmental or styling damage.
4. Apply Product While Wet: Apply your styling products (leave-in conditioner, curl cream, or serum) when the hair is still soaking wet. This technique encapsulates the water inside the hair shaft before the air dries it out, preventing the cuticle from opening to seek moisture.
5. Sleep on Silk or Satin: Swap cotton pillowcases for silk or satin ones. Cotton absorbs the hair's moisture and creates friction as you move in your sleep; silk reduces friction and retains hydration.
6. Use a Diffuser for Drying: If you have wavy or curly hair, use a diffuser attachment on your hairdryer set to a low-heat setting. This disperses the heat gently and prevents the fast airflow from disrupting the natural wave pattern and raising the cuticle.
7. Avoid Over-Brushing: Only comb wavy, curly, or coily hair when wet and detangled with conditioner. For straight or slightly wavy hair, use a boar-bristle brush lightly once dry to distribute natural oils and smooth the top layer of frizz.
8. Limit Heat Styling: Reduce the frequency of blow drying and flat ironing. When you do use heat, always apply a high-quality heat protectant spray that acts as a barrier, preventing extreme water loss from the hair shaft.

Frizz-busting products

The right products are formulated to either smooth the cuticle or provide a hydrophobic barrier against environmental moisture. Look for key ingredients that promise moisture retention and protection.

• Sulfate-Free Shampoos: These gentle cleansers cleanse without stripping the hair of its essential natural oils, maintaining the hair's innate moisture barrier.
• Silicone-Based Serums and Oils: Products containing silicones (like dimethicone) or natural oils (argan, coconut, or jojoba) create a smooth, waterproof layer around the hair strand. This prevents humidity from penetrating and causes the cuticles to lie flat.
• Leave-In Conditioners: These are essential for providing a base layer of hydration after washing. They work to detangle and nourish the hair without the weight of rinse-out conditioners.
• Glycerin: This humectant draws moisture from the environment into the hair shaft. However, use caution: in extremely humid weather, glycerin can draw too much moisture in, causing hair to swell and frizz. In dry weather, it is highly beneficial.
• Anti-Humidity Sprays: These finishing sprays often contain high concentrations of anti-frizz polymers that create a flexible shield over the hair, specifically designed to block the effect of high humidity.

Takeaway

Frizzy hair is a universal challenge, but it is fundamentally a sign of dry, damaged, or thirsty hair. The solution lies in gentle care and conscious hydration. By avoiding harsh, stripping cleansers, eliminating friction from cotton towels, and sealing in moisture with cool water and smoothing products, you can train the hair cuticle to remain flat and resist the swelling effects of humidity. Making small changes to your washing and drying routine can lead to dramatically smoother results over time.