Hair Relaxer Strengths

Any discussion of relaxer strength starts all the way back in the lab.

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Hair relaxer is serious business, and DIY beauty fans need to know how to handle these products. If used incorrectly, relaxer can make even the most lushly-tressed beauty into a cue ball within minutes. To top it off, you can even come out with a painful array of chemical burns all over your scalp. Avoid this fate and increase your chance of relaxer success with some consideration about relaxer strength. By purchasing the correct relaxer formulation for your type of hair, it's a pretty good bet that you'll avoid the bald 'n' shiny look.

What's in a Relaxer?

The active ingredient in a lye relaxer is sodium hydroxide. For the most part, only a pro should handle a lye relaxer since products that contain lye process quickly and are very strong. No-lye relaxers utilize lithium, potassium, calcium or guanidine hydroxide, and take a little longer to straighten the hair. The manufacturer may also add other products like jojoba oil, olive oil and shea butter to improve relaxer performance and soften the hair.

Gentle Strength

According to Design Essentials, a low-lye relaxer contains less than 2.5 percent active sodium hydroxide. This tiny amount of product guarantees a relaxer that also leaves some texture in the hair. It's also much less likely to burn the scalp, even if it remains on longer than package directions advise. Children's relaxer formulas also tend to be on the gentle side, since their scalps can be extremely sensitive.

Regular Strength

A regular-strength relaxer is strong enough to work on the average head of hair. Within the set amount of application time on the package, a person with an average amount of hair should be able to apply product all over, smooth the roots and rinse. Most people will find that normal-strength relaxer does the job. See if your hair is normal by putting a small amount of regular-strength relaxer on a hidden section. If it flattens out within the allotted amount of time, then you're a regular girl. If not, it's time to bring in the big guns: coarse or resistant relaxer.

Coarse Strength

This relaxer strength is for hair that simply wants to go its own way. In short, the hair wishes to stay curly, and you want it to be straight. Resistant hair requires a stronger formula and a slightly longer application time in order to achieve the desired result. You can use regular strength on resistant hair, but the thicker strands simply won't flatten as well with the smaller concentration of active ingredients, and texture will still be evident in the end. Therefore, resistant-strength relaxer guarantees a better result for stubborn hair.


It's safe to use a relaxer that's too weak, although you'll kick yourself if the hair stays a little curly after the process is finished. What's dangerous is using a stronger formula than necessary. Since a relaxer is a severe process that actually breaks down the hair's composition, treating delicate strands to a sledgehammer-strong relaxer formulation is a recipe for disaster. If in doubt, use a gentle or regular formula, then progress to coarse if curl is still evident. An overly strong formula won't make your hair straighter, but it will create much more damage than necessary.

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