Difference Between Lye & No-Lye Relaxer

Relaxers can stretch tight curls into longer, silky tresses.

Relaxers are the straightening method of choice for many women with curly, tightly coiled or kinky hair. These chemical treatments work by entering the cortex, or inner layer, of the hair shaft and transforming its structure, resulting in straightened tresses. When choosing a relaxer, consider factors such as the amount of time it takes to straighten hair, as well as the relaxer's chemical makeup. The two basic types of relaxer are lye-containing products and no-lye products.

Identification

The main difference between lye and no-lye relaxers comes down to their active ingredients. Sodium hydroxide serves as the active ingredient in lye relaxers, which are available in base and no-base formulas, base formulas being the more potent of the two. The active ingredient in most no-lye relaxers is guanidine hydroxide, a powerful combination of calcium hydroxide and guanidine solution, which activates the mixture. Many lye and no-lye relaxers also contain conditioning ingredients such as olive oil and shea butter to help soften the hair.

Significance

Both relaxer types use caustic chemicals to straighten hair, but no-lye relaxers are less likely to irritate the scalp, according to MedicineNet.com. Even so, regardless of which relaxer type you choose, factors such as individual scalp sensitivity and the overall harshness of the chemicals may still cause chemical burns and hair breakage and loss. "Any relaxer can burn your scalp if you use it the wrong way," the FDA warns.

Advantages

Lye relaxers tend to be the more convenient and practical straightening option of the two. They do not have to be mixed and are packaged in larger containers, allowing for multiple applications. A professional stylist can quickly and easily apply these chemical straighteners, eliminating any guesswork. Due to the stronger formulation of lye relaxers, which have a pH factor ranging from 10 to 14, these chemical treatments work more quickly to break down hair bonds and straighten the hair. Specifically, base lye relaxers are thought to be more effective in fully straightening the hair.

No-lye relaxers, on the other hand, are the more economical and accessible choice. Most kits ring up for approximately $6 to $10, as of June 2010, and are readily available in supermarkets and drug and beauty supply stores. Because they tend to cause less scalp irritation, they are considered a more appropriate choice for women with sensitive scalps.

Disadvantages

Lye relaxers are often more irritating and damaging to both the hair and scalp. Because these products are typically available for use only by licensed cosmetologists, you will pay more for professional application, which usually starts at a price of approximately $40.

No-lye relaxers come packaged with instructions but leave much room for error when applied at home. Because of their milder formulation, these chemical straighteners must stay on the hair longer for processing, which can result in dry, limp tresses, often from mineral deposits left on the hair. No-lye relaxers, most of which have to be mixed, do not have a shelf life once prepared; for best results, you should use them shortly after mixing.

Considerations

Whether using lye or no-lye relaxer, take care to protect both your scalp and hair. Apply a cream similar to petroleum jelly to the scalp before using a base lye relaxer. Some women who use at-home kits, as well as professional stylists, prefer to use this cream as a protective layer regardless of the type of relaxer being used.

Neither type of relaxer should be applied to damaged hair or an irritated scalp, as this can lead to additional breakage and chemical burns. Because these chemical treatments can leave the hair more dry and fragile, follow up relaxers with a replenishing deep conditioner.

References

• MedicineNet.com: Heading Off Hair-Care Disasters: Use Caution With Relaxers and Dyes
• U.S. Food and Drug Administration: Hair Dye and Hair Relaxers
• Skin & Allergy News: Relaxers Can Cause African Americans' Hair Loss
• My Salon Scoop: Lye, No-Lye Relaxers...What's the Difference?
• Skin Biology: The Truth About Hair Relaxers