One of the first questions we get about clip-ins is whether you can use a curling iron or straightener on them. The short answer: yes — as long as they're real human hair and you treat them a little more carefully than your own. Here's how to curl, straighten and blow-dry clip-in extensions so they look like your hair and stay soft for the life of the set.
Yes — if they're 100% human hair
Synthetic extensions are plastic fibers; heat melts or frizzes them permanently. Human hair extensions behave like your own hair, so they can be curled, straightened, blow-dried and even set in rollers. Every Sandy Bella set — clip-in, tape-in and halo — is 100% Remy human hair, so heat styling is fine within the temperature rules below.
Not sure what you already own? Snip a single strand from the underside of a weft and touch it with a hot tool for a second. Human hair will simply warm and smell faintly like burnt hair; synthetic fiber will curl into a hard bead.
The temperature rules
- Stay under 350°F (180°C). Higher heat breaks down the cuticle over time, which is what makes extensions dull, dry and tangle-prone. Most looks hold perfectly at 300–330°F.
- Go lower on light shades. Blonde and highlighted hair has been lifted, so it's more fragile — start around 300°F.
- Always use a heat protectant. Extensions don't receive natural oils from your scalp, so they dry out faster than your own hair. Mist every weft before any hot tool touches it.
- Style dry hair only. Never iron damp extensions — the steam boils moisture inside the hair shaft.
How to curl clip-in extensions
- Clip the set in first, then curl your hair and the extensions together in the same sections. Styling them as one head of hair is the single best blending trick.
- Choose a 1" to 1.5" barrel for soft, natural waves. Tighter barrels look great but show the transition line more.
- Take sections no wider than the barrel, wrap away from the face, and hold for 8–10 seconds — no longer.
- Let each curl cool completely in your palm before touching it. Cooling is what sets the shape.
- Once everything is cool, break the curls up with your fingers or a wide-tooth comb and finish with a light, flexible hairspray.
Prefer to curl the wefts off your head? Lay them on a heat-resistant mat, hold the clips flat, and curl section by section — just keep the iron a finger's width away from the weft stitching.
How to straighten them
- Brush the set out fully first, starting from the ends and working up.
- Use a fine-tooth comb just ahead of the flat iron so each section is smooth before the plates reach it.
- One or two slow passes at 300–330°F is enough. Repeated passes over the same section are what cause damage, not the temperature alone.
- Never clamp over the clips or the top of the weft — start about an inch below.
- Finish with a drop of argan or shine serum through the ends only.
Blow-drying after a wash
Let the wefts air-dry until they're about 80% dry, then finish with a dryer on low heat and a round brush, always pointing the airflow down the hair shaft. Don't blast the weft stitching with concentrated heat, and don't brush the hair while it's soaking wet — that's when it stretches and snaps. Our care guide covers washing and drying step by step.
Heatless volume
For everyday wear you don't need heat at all. Braid the dry wefts loosely overnight, or set them in large foam rollers, and unclip them in the morning with soft, bouncy waves that last all day. Every heat-free style you do is extra months on the life of the set.
Signs you're using too much heat
Rough, crunchy ends, hair that tangles within an hour of brushing, and a dull finish that shine spray can't fix all point to cuticle damage. Dial the temperature back, skip heat for a few wears, and deep-condition the mid-lengths and ends with a sulfate-free, alcohol-free conditioner. Caught early, the hair usually bounces back.
Styled right, a set of Sandy Bella clip-ins will take everything from beach waves to a sleek blowout for a year or more. Shop 100% Remy clip-in hair extensions in 20" and 24".