How to Apply a Keratin Treatment: A Complete Step-by-Step Guide

A professional keratin treatment can help smooth the appearance of the hair, reduce frizz, improve manageability and leave hair looking smoother and shinier.

While individual treatment lines have their own requirements, professional keratin treatments generally follow the same basic process: cleanse, prepare, apply, develop, rinse, blow-dry and seal the treatment with professional heat.

The main differences between Renew Hair Professional's keratin treatments are typically the development time, flat-iron temperature and number of passes, which can also need to be adjusted according to the hair's type, texture and condition. Always check the specific product line before starting to make sure you are using the correct timings and heat settings.

Step 1: Cleanse the Hair

Begin by thoroughly cleansing the hair with a professional deep-cleansing or clarifying shampoo. Massage the shampoo through the hair and rinse thoroughly.

The hair may need to be shampooed more than once to remove product build-up, oils and residue and properly prepare the hair for treatment.

Step 2: Prepare the Hair

After cleansing, gently towel-dry the hair to remove excess water.

Rough-dry the hair until it is approximately 80–90% dry before application.

The required level of dryness can vary between treatment lines, so check the specific product before application.

Step 3: Apply the Keratin Treatment

Divide the hair into four sections, beginning at the nape of the neck.

Working with small sections of approximately 0.5–1cm, apply the treatment evenly from root to ends, leaving approximately 0.5cm between the product and the scalp. Do not apply directly to the scalp.

Continue working through the hair systematically, combing through each section to distribute the product evenly and remove any excess.

More product does not mean better results. The aim is even coverage rather than unnecessarily saturating the hair, which can make the hair heavy and affect the finishing process.

Step 4: Allow the Treatment to Develop

Once the treatment has been applied, allow it to develop for the required amount of time.

Development time can vary between treatment lines, as well as according to the hair's texture, condition, porosity and the desired result.

Always check the specific product line for its recommended development time rather than applying the same timing to every treatment.

Step 5: Rinse and Treat

After the development stage, rinse the hair thoroughly with water, following the requirements of the treatment being used.

Some professional systems may then include a specific mask or conditioning treatment before the final blow-dry.

If your treatment includes a mask or finishing product, apply it as directed for that particular product line before continuing to the next stage.

Step 6: Apply Finishing Product and Blow-Dry

Where appropriate, apply a small amount of a suitable finishing product such as Argan Oil.

Blow-dry the hair completely until it is 100% dry, preparing it for the heat-sealing stage.

A round brush can be used during blow-drying to help smooth the hair and create a straighter finish where appropriate.

Step 7: Seal the Treatment with Heat

Once the hair is completely dry, divide it into small sections of approximately 0.5cm and use a professional flat iron to seal the treatment.

Work systematically from the nape upwards, passing the iron evenly through each section from root to ends.

The flat-iron temperature and number of passes vary between treatment lines and should also be selected according to the condition and type of hair being treated.

Do not assume that 230–235°C is suitable for every treatment or every client. Fragile, bleached, fine or highly processed hair may require a lower temperature and fewer passes.

This is an important part of the treatment process, so always check the specific product line for its recommended temperature and number of passes.

Step 8: Finish and Maintain

Once the treatment is complete, follow the appropriate finishing and aftercare requirements for the product used.

Different treatment lines may have different recommendations regarding when the hair can next be washed, how it should be styled and which aftercare products are most suitable.

Using appropriate professional aftercare can help maintain the look and feel of treated hair for longer. A gentle shampoo, nourishing mask and suitable leave-in treatment can all form part of a good maintenance routine.

FAQs

How Long Does a Keratin Treatment Last?

Results vary depending on the treatment used, hair type, texture, condition and home-care routine.

Many professional smoothing treatments can provide results lasting several weeks to a few months when combined with suitable aftercare.

Can Keratin Treatments Be Used on Coloured or Damaged Hair?

Some professional keratin systems are suitable for coloured or chemically treated hair, while others may be better suited to particular hair conditions.

A professional should assess the condition of the hair before treatment. Highly damaged, fragile or over-processed hair may require a different approach, lower heat or may not be suitable for treatment at that time.

Always check the suitability of the individual treatment line before application.

How Often Should a Keratin Treatment Be Repeated?

There isn't one treatment schedule that suits everyone.

The ideal timing depends on the individual product, the condition of the hair, previous chemical or smoothing treatments and the level of smoothing desired.

A professional should assess the hair before repeating a treatment and consider the requirements of the treatment line being used.

Professional Application Matters

Keratin and smoothing treatments involve professional formulations and, in many cases, significant levels of heat. They should be carried out by a trained professional using appropriate application and safety procedures.

Although the general treatment process is similar across professional systems, products are not interchangeable. Development times, heat requirements and number of passes can vary between treatment lines, and the approach may also need to be adapted to the condition and type of hair being treated.

Before carrying out a treatment, make sure you are familiar with the specific product's ingredients, warnings, contraindications, ventilation requirements and application process.

Looking for Professional Keratin Products?

Explore the Renew Hair Professional range of keratin, smoothing and aftercare products, designed to help professionals create smooth, manageable, salon-quality results.