Can You Use Flat Iron After Keratin Treatment? (After Care Advice)

flat iron to use after keratin treatment: black pen beside gold and silver key

If you’re someone who has recently undergone a Brazilian blowout or Brazilian keratin treatment, you’re probably wondering if you can still straighten your hair using a flat iron. Well, the answer is yes!

In fact, you need to use flat iron twice a day for 72 hours after treatment to make the keratin seals on the hair fiber completely.

However, before you continue, you need to know which flat iron is best to use and how to properly style your hair using it without damaging hair or ruining the treatment.

Can you use flat iron after keratin treatment?

flat iron to use after keratin treatment: woman holding her white shirt flipping hair

Straightening your hair with a flat iron is one of the most popular heat styling tools out there, and it’s great for achieving smooth and sleek hair.

And, while it’s true that keratin-treated hair is more delicate than untreated hair, you can still use a flat iron without damaging it.

However, you need to be cautious while selecting flat iron and temperature to heat your hair because you might damage it.

Here’s how to properly use flat iron on keratin treated hair:

  • Use a heat protectant spray: Before using a flat iron, make sure to apply a heat protectant spray to your hair. This will help protect your keratin treated hair from excessive heat.
  • Set the optimum temperature: If your flat iron has adjustable heat settings, make sure to choose a lower temperature. It is recommended to use a flat iron at 450 degrees Fahrenheit or 232 degrees Celsius.
  • Make section of your hair: Divide your hair into smaller sections to make flat ironing easier and ensure you don’t miss any strands. Start with the bottom layers of your hair and work your way up.
  • Flat iron each section: Take one section of hair and place the flat iron at the root. Slowly glide the flat iron down the length of the hair, making sure to keep the flat iron moving to avoid damaging your hair. Repeat this process with each section of hair.

By following these steps, you won’t damage your hair while using flat iron on keratin treated hair.Just remember to be gentle and avoid over-styling your hair, as this can cause damage and reduce the longevity of your keratin treatment.

What happens to keratin when heated?

Keratin smoothing treatment is done to tame frizz, reduce volume, and give hair a sleek, glossy appearance.

In this procedure, keratin solution is applied to the hair and left for hours in most cases. Then, the hair is heated with iron to seal the keratin on the outer surface of the hair.

Heat causes protein molecules in keratin to cross-link, or bond together creating a seal over the outer layer of hair. This creates a change in the texture and appearance of the hair making it straight, smooth, and frizz-free.

However, if you overheat the keratin-treated hair, it does more damage to it. 

When keratin is exposed to high temperatures, the heat can cause the protein molecules to unravel and denature, and lose their shape. This can result in damage to the hair making it dry, brittle, and prone to breakage.

Also, prolonged exposure to high heat can cause the protein molecules in keratin to coagulate or clump together. This can result in a loss of elasticity and a reduction in the ability of the hair to stretch and return to its original shape.

Reason to use flat iron after keratin treatment

  • To help maintain the sleek and straight appearance of the hair.
  • To keratin seal the hair fiber properly and adhere to it completely
  • To make hair dry and moist-free for 72 hours.

Best flat iron to use after keratin treatment

When choosing a flat iron to use after a keratin treatment, there are a few things to consider to ensure the best results.

Ceramic or tourmaline plates are ideal for use after a keratin treatment. These materials help to distribute heat evenly and avoid hot spots that can damage the hair.

Also, flat iron should have adjustable heat settings to it to avoid overheating and damaging the hair.

Here are some of the best flat iron to use:

  • BaBylissPRO Nano Titanium Ultra-Thin Straightening Iron
  • GHD Platinum+ Professional Performance Styler
  • Dyson Corrale Hair Straightener.

These flat irons are well-regarded for their heat control, plate material, and quality, making them ideal for use after a keratin treatment.

Air drying hair after keratin treatment: Is it recommended?

It is a good idea to air dry your hair after a keratin treatment and in fact, it can be a great choice to avoid additional heat damage to your hair.

Heat styling tools, such as a hair dryer or flat iron, can damage the hair, especially if used frequently. By air drying your hair after a keratin treatment, you can avoid the added heat exposure and protect the hair.

Other Keratin Treatment Do’s and Don’ts


  • Don’t wash your hair for 72 hours after your keratin treatment.
  • Keep your hair down at all times.
  • Use a blow dryer and flat iron on your hair if it gets wet during the first 72 hours.
  • Style your hair with a blow dryer and brush if desired during the 72 hours.
  • Cover your hair with a shower cap when bathing.
  • Wear a silk scarf to keep your hair away from your face.
  • Use sodium-chloride-free aftercare products, such as GK shampoo and conditioner or Keratin Complex Care, or Keratin Color Care Shampoo and Conditioner, to protect the keratin in your hair.
  • Protect your hair from salt and chlorine damage while swimming by wetting your hair with clear water and applying a deep conditioner or serum/oil before entering the water.


  • Avoid washing or wetting your hair for 72 hours (3 days).
  • Don’t put your hair in a ponytail as it may leave lasting marks.
  • Avoid using hair clips, hair bands, or bobby pins as they may leave lasting marks.
  • Don’t keep your hair behind your ears for extended periods.
  • Don’t rest your glasses on your head or use them to hold your hair back.
  • Try to minimize sweating.

Bottom Line

Can you use flat iron after keratin treatment? You can use it after keratin treatment. Use them when your hair is wet or kinky.

Also, it is advisable to heat your hair with a ceramic plated flat iron at a recommended temperature which is 400F, two times a day for 72 hours to make keratin on your hair seal the outer layer of hair completely.

However, avoid high temperatures or prolonged exposure to heat as it damages the keratin molecules decreasing its effectiveness. In the worst case, it can also damage hair making it more prone to breakage.

Similar Posts