Hair Straightening Treatments

Heat-activated straightening treatments and complete kits from the Hair Liss Perfect line, including Brazilian keratin straightening and toning options for blonde hair.

How Heat-Activated Hair Straightening Works

The treatments on this page are applied to clean, dry hair, left to process under a plastic cap, rinsed, and then sealed with a blow dryer and a flat iron. The heat step is what sets the smooth result, which is why sectioning and careful ironing matter as much as the product itself.

The result is temporary. It fades gradually as you wash your hair, and new growth keeps your natural texture. If you want softness and frizz control more than a straight finish, see the wider range of keratin treatments.

Brazilian Keratin Straightening Kits

“Brazilian” straightening refers to this style of smoothing service: a keratin-type treatment sealed with heat for a sleek, glossy finish. The Hair Liss Perfect line follows that method. The Brazilian keratin straightening kit with hair perfume pairs the 1000 mL treatment with a finishing fragrance; the standard kits come in 100 mL, 300 mL and 1000 mL.

Choosing a Size and a Bundle

  • 100 mL — short hair, or a first treatment.
  • 300 mL — medium-length hair.
  • 1000 mL — long hair and salon use; also sold as the treatment on its own.
  • Blonde hair — the Blond toning treatment smooths while helping neutralize yellow tones.
  • With preparation — bundles that add the Excelencia pre-treatment kit condition porous or processed hair first.

Every routine starts with a clarifying shampoo and ends with a heat protectant before the blow-dry.

Professional Use and Safety

These products are labeled for professional use. They are intended to be applied by trained stylists. If you are not trained, we recommend having a licensed professional carry out the treatment.

Heat-activated smoothing treatments should always be used in a well-ventilated area and exactly as directed on the label. The U.S. Food and Drug Administration has warned that some hair smoothing products can release formaldehyde when heated. Read the ingredient list and warnings on any product you use, do a strand test first, avoid contact with eyes and skin, and stop if irritation occurs.

If you are weighing up doing the process yourself, read keratin treatment at home: what to know before you start.

After the Treatment

The directions for Hair Liss Perfect allow washing afterward using only a mask or a hydrating conditioner, then drying and styling as usual. From then on, gentle washing and regular conditioning help the result last. See the aftercare guide and the post-keratin hair care collection.

Hair Straightening Questions

Is a hair straightening treatment permanent?

No. The smooth result fades gradually with washing, and new growth has your natural texture. The directions say to repeat the full treatment only every 3 to 6 months and to touch up just the roots in between.

How long does the treatment stay on the hair?

According to the product directions, 40 minutes for fine hair and 60 minutes for thick hair, under a plastic cap, before rinsing with lukewarm water. Do not use an aluminum cap or a dryer to speed it up.

What temperature should the flat iron be?

Follow the directions for your hair type. For blonde hair, the directions say to use one or two settings below the maximum. Thick hair needs thinner sections rather than more heat.