Chemical Modification of Previously Treated Hair

Understanding Hair Structure and Chemical Treatments

Hair's protein structure is composed of keratin chains held together by various bonds: disulfide, hydrogen, and salt bonds. Chemical services like permanent waving (perms) and lightening (bleaching) alter these bonds to change hair's shape and/or color. A crucial understanding of hair's porosity, elasticity, and overall health before any chemical service is vital to prevent damage.

Permanent Waving: Altering Disulfide Bonds

Permanent waving involves breaking disulfide bonds within the hair's cortex using a reducing agent (typically ammonium thioglycolate). The hair is then reshaped around rods, and an oxidizing agent (usually hydrogen peroxide) reforms the disulfide bonds in the new configuration, creating a curl or wave pattern.

Hair Lightening: Oxidation of Melanin

Hair lightening utilizes oxidizing agents, such as hydrogen peroxide or persulfates, to break down melanin pigments within the hair shaft. The concentration of the oxidizing agent, processing time, and heat influence the degree of lightening achieved. This process can weaken the hair's structure and increase its porosity.

Potential for Damage: Combining Chemical Processes

Applying lightening treatments to hair that has already undergone permanent waving significantly increases the risk of damage. Both processes weaken the hair's structure and can lead to increased porosity, dryness, breakage, and elasticity loss. Overlapping chemical treatments can cause severe and potentially irreversible damage.

Assessing Hair Condition Prior to Further Chemical Treatment

Before considering any additional chemical service, a thorough assessment of hair condition is essential. Evaluate porosity by observing how quickly hair absorbs water. Check elasticity by gently stretching a wet strand to see if it returns to its original length without breaking. Look for signs of damage, such as split ends, breakage, and a rough texture.

Protein and Moisture Balance

Maintaining a proper balance of protein and moisture is essential for healthy, chemically treated hair. Protein treatments can help strengthen weakened hair bonds, while moisturizing treatments help replenish lost moisture and improve elasticity. A deep conditioning regimen can help restore strength and hydration.

Considerations for Subsequent Color Changes

If further alteration of hair color is desired after a permanent wave, it is typically recommended to avoid lightening and consider darkening the hair with deposit-only color. Doing so minimizes the risk of additional damage. Toners may be used to neutralize unwanted tones. A strand test is always recommended to assess how the hair will react and achieve the desired color result. Professional consultation with a trained stylist is strongly advised.

Professional Consultation and Treatment

Due to the complexities and potential risks associated with chemically modifying previously treated hair, seeking advice from a qualified and experienced professional hairstylist is highly recommended. A professional can accurately assess hair condition, provide tailored recommendations, and perform the service safely, minimizing the risk of damage and achieving the desired outcome. They can also advise on appropriate aftercare products and maintenance routines.