How Does Heat Lead to Damaged Hair?

Heat Styling Tools and Damage

Using hot tools like blow dryers, flat irons, and curling irons increase the chances that you'll experience damaged hair from heat. Some tools don't allow for temperature control, and can reach more than 400°F. Temperatures over 300°F convert the α-keratin to β-keratin, making the hair weaker and less elastic. Once keratin is melted, the damage is molecular and irreversible.

Damaged Hair Lacks Moisture

Heat damages the cortex inside your hair, where water molecules bind to proteins. When exposed to high heat, water evaporates, oils are stripped, and the structure weakens. Cuticles crack open like raised shingles, leading to split ends, roughness, and frizz.

Managing Heat Damaged Hair

Once your hair is heat damaged, it can't be reversed — but it can be managed:

• Cut off the damaged parts, little by little or all at once.
• Use leave-in conditioners, oils (like argan or jojoba), and protein-rich treatments.
• Limit heat tool usage and keep temperatures between 200°F and 300°F.
• Use a heat protectant before styling.
• Let hair air-dry whenever possible.