Keratin or Relaxer Hair Treatment: Which Is Better?

Textured and curly hair is beautiful to flaunt. However, its manageability becomes a big issue, especially in the scorching summer. This is where the importance of straightening and softening the hair comes into play. 

Hair straightening and softening tame the hair, making it frizz-free, silky, and bouncy. Multiple options are available for straightening, but most prefer a keratin or relaxer treatment as it is convenient. 

Relaxer treatment is a chemical treatment that permanently straightens extremely coiled hair. It includes breaking disulfide bonds and restructuring them. (1)

Keratin treatment is a semipermanent treatment (2) that makes managing curly hair effortless. It reduces frizz and improves shine and color, making the hair look healthy. (3)

But the question that might cross your mind is, what’s better for your hair?

The answer is that a keratin treatment is better than a relaxer treatment. According to 2022 research, keratin treatment is safer as it is less harsh than a relaxer treatment. (3)

Continue reading to unfold the differences between keratin and relaxer treatments and what’s better for you.

Keratin Treatment or Relaxer Treatment: What to Choose?

According to experts, a keratin treatment is more suitable than a relaxer-based treatment, as keratin treatment is a less harsh treatment for those with frizzy hair. It is for people who want long-term smooth and straight hair.

The chemicals in keratin treatments are less harmful than those in harsh relaxer treatments. The main difference between keratin and relaxer treatments is the longevity of the straightened hair. 

Keratin treatment loosens the curl pattern temporarily; the results fade with time, and the texture of your hair will return to its natural state. Relaxer treatments permanently straighten the hair by breaking down the molecular bonds. (1)

A 2022 research reported that on the surface level, Brazilian keratin treatments are safer alternatives to chemical hair relaxer treatments. 

Keratin treatment makes naturally curly hair frizz-free and more manageable; it also enhances its shine and color and gives a healthier appearance to the hair. Although used widely, keratin treatment has virtually no reports of any side effects. 

Unfortunately, products used by salon professionals contain formaldehyde or its derivatives but are marketed as safe. (4)

According to the manufacturers, keratin hair treatment can be used on highlighted, chemically relaxed, and color-treated hair.

Note: The US Cosmetic Ingredient Review Expert Panel share that 0.2% is the maximum safe formaldehyde concentration. (3)

Relaxer treatments take at least 30–60 minutes, but their results stay for 6–8 weeks. Keratin treatments require 2–4 hours, but their effects remain for about 4–6 months. 

According to a 2022 research, relaxer usage has declined over the past decade as people have begun to realize the harmful effects of frequent chemical exposure. 

A consumer study revealed that there was a 26% decrease in the sales of relaxers between 2008 and 2013 and a 17% decrease between 2006 and 2011. (3)

Based on expert documentation, the advantage of keratin treatment over relaxer treatment can be concluded. 

Know More About Relaxer Hair Treatments

Read on to know more about the relaxer hair treatment, types of hair relaxers, its mechanism, risks, etc.

What is a relaxer hair treatment?

Hair relaxing is originally referred to as lanthionization. (3) It is a chemical treatment that permanently straightens highly coiled hair by restructuring the broken disulfide bonds. (1) Chemical relaxers are official hair straighteners. (5) 

A chemical relaxer can only permanently straighten afro-textured hair by breaking and rearranging disulfide bonds in the hair shaft. The ingredients involved are potassium hydroxide or sodium hydroxide mixed with potato starch. (3)

How does it work?

In this technique, the protein structures held together in the hair strands by disulfide bonds are broken down during relaxation. Hair elements are rearranged and manipulated to alter the overall hair texture. (1)

No-lye relaxers reduce the chemicals that weaken the cystine bond of hair rather than disrupt the entire protein structure. (5)

Types of hair relaxers

Chemical hair relaxers are classified as lye (sodium hydroxide), no-lye (calcium hydroxide), and ammonium thioglycolate. (6)

1. Lye relaxers

Lye relaxers are referred to as soda-containing straighteners and contain sodium hydroxide as an active ingredient.

When lye relaxers are used, a lanthionization reaction occurs, where hydroxyl ions break the disulfide bonds, developing lanthionine. The disulfide bonds rearrange, and cysteine converts into lanthionine. This process makes hair straightening irreversible.

Lye relaxers are alkaline with a pH of 13–14, and scalp irritation may occur. (2) They may take only 20 minutes to straighten hair. (5)

2. No-lye relaxers

No-lye relaxers are non-hydroxide straightening products containing ammonium thioglycolate, guanidine hydroxide, or lithium. (5)

People of African descent and those with sensitive scalp and curly hair are recommended to use no-lye relaxers. As these are non-hydroxide straightening products, they are less irritating than sodium hydroxide or lye relaxers. (2)

3. Ammonium thioglycolate relaxers

When ammonium thioglycolate relaxers are used, the disulfide bonds are converted into sulphydryl groups, allowing mechanical relaxation of the protein structure of the hair fibers.

The oxidization of thioglycolate with ammonia, sodium hydroxide, monothanolanine, or other agents follows. Applying hot iron during this process allows permanent straightening.

Protein loss is less when using thioglycolate than when using hydroxide. (2)

Note:

• According to research, no-lye relaxers (guanidine hydroxide) were less irritating on the scalp than lye relaxers (sodium hydroxide). (5)
• Thioglycolate and hydroxides are not compatible with one another. If your hair has already been treated with hydroxides, it cannot be treated with thioglycolate. They are not compatible with bleached hair as well. (5)

Procedure

Whether done by a professional hairstylist or by you, the procedure includes the following steps.

1. The hair is examined to pick an ideal relaxer, which depends on hair porosity, coarseness, curliness degree, and previous treatments.
2. The hair is shampooed to remove sebum or product buildup. 
3. The ears and hairline are protected with cotton or petrolatum to prevent skin burns due to the highly alkaline solution.
4. The hair is parted into quadrants, and the product is applied using a comb or brush or by smoothing or massaging the product with the fingers. 
5. After the product’s application, the process is worked to the roots; the strands are smoothened until the hair is straightened.
6. The relaxer is left for 5–30 minutes on the hair, preferably 8–26 minutes.
7. After the allotted time, a conditioning shampoo with a pH between 4.0 and 6.0 is used to wash hair. The hair is then rinsed clean and dried. (2)(7)

On porous hair, the relaxer is left for 13–17 minutes; for medium-porosity hair, 18–22 minutes; for nonporous hair, 23–26 minutes. (7)

Note: Lye relaxers are commonly used in professional hair salons, and no-lye relaxers are usually for at-home use. (3)

Time required

Depending on your hair length, a hair relaxer treatment can take 30 minutes to 1 hour.  

Post-treatment measures

Taking care of your relaxed hair properly is crucial to maintain its shape. Here’s how you can do that:

• Wash your hair with a gentle, sulfate-free shampoo; it doesn’t remove the scalp’s natural oil. 
• Use lightweight yet deep-penetrating oils and leave-in conditioner regularly to keep the moisture balance.
• Go for deep conditioning once a week and moisturizing mask for extra hydration.
• Avoid heat-styling tools such as curling irons and flat irons, as they cause dryness.
• Give your hair a regular trim to remove fragile and porous ends.

How long does it last?

After chemical application, a hair relaxer treatment will straighten your hair quickly, and the results will last for about 6–8 weeks.

New strands that will grow will be relaxer-free. Thus, you may need touch-ups to transform curly hair into straight ones and maintain a straightened look.

Sometimes, a relaxer treatment can result in overprocessing, making the hair thin and causing breakage. 

Risk and side effects

According to a 2019 study, relaxer treatments increased the chances of hair breakage, burns, scalp irritation, traction alopecia (TA), allergic reactions, and scarring. (8)

The most common risk is carcinogen exposure, hair damage, skin irritation, hair loss, endocrine-disrupting chemical exposure, and lack of exercise-friendly hairstyle options. (3) 

The lanthionization process uses extremely alkaline chemicals. They can not only lead to chemical skin burns, but their extended presence on the hair also starts digesting the hair itself.

Also, relaxers alleviate hair sulfur content, weakening the hair with increased fragility, thinning, and breakage. (3)

Recommendations

• Getting relaxer treatments from an experienced professional that observes the appropriate processing time and proper application methods is highly advised. 
• The client’s scalp and hair condition must be evaluated before the application. If your scalp is compromised, relaxers must be avoided, even after using the base.
• Relaxers must be left on porous or thin hair for a little while to achieve the desired result as they process faster.
• There are different opinions on how frequently relaxers must be used on the hair, varying from every 6–8 weeks to 8–12 weeks. However, frequent application can lead to breakage and damage.
• After relaxing your hair, avoid excessive combing, styling, and high-tension styles to prevent traction alopecia and breakage. (3)

Know More About Keratin Hair Treatments

According to a 2022 study, keratin, which is found in the hair structure, is directly involved in resistance, durability, and flexibility maintenance. It plays a role in the shiny appearance and degree of hydration of the hair. 

What is a keratin treatment?

Keratin hair treatments are popular among women nowadays. (9) They are semipermanent treatments (2) also known as Brazilian blowout and Brazilian keratin treatment. (2) 

Keratin hair treatment is a newer hair-straightening method that has become popular because it can straighten hair, reduce frizz, and improve shine for up to 5 months. 

This treatment started in Brazil and includes the application of formaldehyde or formaldehyde-releasing solutions to the hair. It is followed by blow-drying the hair and flat-ironing it to lock the straightening effect. 

The adhesion of synthetic hydrolyzed keratin to the natural hair shaft keratin and proper cross-linking require formaldehyde. According to manufacturers, this treatment can be used safely on highlighted, color-treated, and chemically relaxed hair. (3)

How does it work?

The synthetic hydrolyzed liquid keratin penetrates the cortex quickly and reacts with the keratin in human hair.

During the heating, formaldehyde is released, which fixes the hydrolyzed keratin in the hair’s natural keratin. As a result, a waterproof layer surrounds the hair and seals the cuticles, enhancing the smoothness and shine of bleached or virgin hair.

This layer is not entirely protective; the shaft remains fragile and exposed to ruptures after minimal trauma. 

Procedure

Salon hair experts perform a time-intensive procedure to make the hair smooth and straight. The steps are as follows:

1. Your hair is washed thoroughly for the preparation and is blow-dried or left wet for the next step. 
2. A keratin protein treatment is applied well to the hair.
3. It is left for 20–30 minutes so as to ensure proper time for the keratin treatment to add additional keratin to your hair, thereby reducing frizz, increasing shine, and strengthening the hair.
4. The hair is blow-dried and flat-ironed strategically to seal the keratin bonds again in the hair structure.

Time required 

Keratin treatment takes usually takes 2–4 hours, but the procedure duration also depends on the hair volume, hair texture, and treatment formula.

Post-treatment measures

Handle your keratin-treated hair delicately to maintain it. Here are some tips:

• The next 72 hours after keratin hair treatment is crucial to prevent denting, so avoid tying, styling, and washing your hair. 
• Wash your keratin-treated hair with sulfate-free shampoo and conditioner for manageability. 
• Go for hair care products containing zinc, biotin, and keratin to get shiny, smooth, and silky hair. 
• Avoid chlorine and salt water, as they remove the effects of keratin. 

How long does it last?

A keratin treatment taken from the best salon, with proper after-care, may last up to 4–6 months. 

Risk and side effects 

Brazilian keratin treatment may seem like a safer alternative to chemical hair relaxing. However, it also has risks, as it contains high concentrations of formaldehyde (human carcinogen).

This chemical can cause contact dermatitis, pregnancy complications, respiratory irritations, headaches, and hematopoietic and respiratory malignancies at high concentrations. (3)

Recommendations

• There is a concern about mislabeling Brazilian keratin treatments, and stricter rules must be implemented regarding the use and concentration of formaldehyde-containing products. It was advised to stop using these treatments altogether due to their formaldehyde content and the difference between the listed and carcinogenic ingredients in Brazilian keratin treatment preparations.
• If you smell a strong formaldehyde scent and experience oropharynx and eye irritation during the treatment, abstain from getting the treatment as it is dangerous and unsafe due to the high formaldehyde concentrations.
• Do your own research on the safety and long-term health effects before getting a keratin treatment.

General Queries

Final Word

Both keratin and relaxer treatments can alter your hair texture, making them more manageable and smoother, depending on your natural hair texture and the chemicals used.

However, both these treatments use heat and chemicals that may affect your hair, skin, and overall health. It is highly recommended to get your hair evaluated by a professional hairstylist for a suitable treatment for your hair based on its texture, type, and quality.