The Ultimate Guide to Hair Relaxer: Types, Safety, How to Apply & Aftercare

If you’re thinking about using a hair relaxer, or already do and want to do it better, this guide is for you. Over the years, I’ve seen many friends and clients struggle with breakage, scalp burns, or flat, brittle hair from relaxers. At the same time, relaxers offer a way to simplify styling, reduce time, and achieve straight hair for those whose natural texture is very curly or coily.

But relaxers are not without risks. Applying chemicals to your hair and scalp demands care, knowledge, and good maintenance. This article will walk you through everything—from the basics to advanced aftercare—with real tips, examples, and cautions. I’ll also point out what the science says about long-term risks, so you can make informed choices.

By the end, you’ll have a clear roadmap whether you want to use relaxers, repair damage from them, or explore safer alternatives.

2. Types of Hair Relaxers

There’s no one “hair relaxer” that fits all. The formulas vary, and knowing the type is key to avoiding damage.

Lye Relaxers (Sodium Hydroxide)

These are the traditional relaxer formulas. The active ingredient is sodium hydroxide (commonly called “lye”). They are strong, work fast, and can be more effective for coarse or very tight curls. Because of their strength, they can be harsher on the scalp or hair if misused.

Pros

• Fast and effective, especially for tight, coarse texture

• Good straightening power

Cons

• Greater risk of scalp burns

• Can strip a lot of natural oils

• Must be neutralized very carefully

No-Lye Relaxers (Calcium Hydroxide / Guanidine)

No-lye relaxers use a gentler base. Usually the combination is calcium hydroxide + guanidine carbonate. They are milder on the scalp but can leave hair with mineral buildup, which means you may need clarifying shampoos occasionally.

Pros

• Gentler on scalp

• Less burning sensation (in many cases)

Cons

• May leave mineral buildup

• Can be less effective for extremely tight, coarse hair

• Slower action or weaker straightening

Thio / Ammonium Thioglycolate Relaxers

Less common for extreme straightening, these relaxers break disulfide bonds in a different way. They are often used in combination with processes like keratin treatments in some settings.

Pros

• More control in reducing curl (rather than fully straightening)

• Milder options

Cons

• Not always strong enough to fully straighten coarse hair

• May still cause damage if misused

“Natural” / Botanical Relaxers

Some products promote “natural” or “botanical relaxers”—using enzymes, milder compounds, or plant-based chemicals to gradually loosen curls. These are less aggressive but also less dramatic in effect.

These may be safer, but results vary widely depending on hair type. Many still contain chemical agents.

Pros & Cons Summary

Knowing which type your hair and scalp can tolerate is the first step toward safer use.

Read Also: The Complete Story of “Frankie Says Relax”: Meaning, Legacy, and Cultural Impact

3. How Hair Relaxers Work (Chemistry in Simple Terms)

You don’t need to be a chemist, but understanding the basics helps you use relaxers more safely.

Disulfide Bonds: What Give Curl

Hair is made mostly of a protein called keratin. Within its structure are disulfide bonds—these are chemical bonds between sulfur atoms in the protein chains. These bonds help hair hold shape, curl, and strength.

To relax hair (i.e. straighten it), you need to break or alter those bonds so the hair loses its tight curl pattern. Relaxers do exactly that, in a controlled way.

How Relaxers Break Bonds

• Lye relaxers use a strong alkaline base (sodium hydroxide) to swell hair, open its cuticle, and break the disulfide bonds.

• No-lye relaxers (calcium hydroxide + guanidine) also break bonds by chemical reaction, though usually more gently.

• Once the bonds are broken, the hair is in a more malleable, straighter state.

But breaking the bonds weakens hair. That’s why hair becomes more fragile, more prone to breakage, or damage.

Neutralization (Reforming Some Bonds)

After the relaxer has done its job, you can’t leave it on forever. You rinse and apply a neutralizer—a product (often acidic) that stops the chemical process and helps hair’s pH return to normal. In some relaxers, the neutralizer helps reform some bonds in their new, straighter configuration.

If you skip or rush neutralization, the hair remains under chemical stress, which increases damage.

What Happens to Hair Structure

• The cuticle opens more deeply

• Moisture retention decreases

• Hair can lose elasticity

• The internal structure becomes weaker

Because of that, relaxed hair needs more care (moisture, protein, gentle handling).

4. How to Choose a Hair Relaxer

Using the wrong relaxer or applying it poorly causes many avoidable problems. Here’s how to make a smart choice.

Consider Your Hair Type & Texture

• If your hair is very coarse, dense, or tightly curled, you’ll likely need a stronger relaxer (lye or robust no-lye formula).

• If your hair is finer or already fragile, go for gentler formulas.

Scalp Sensitivity / Condition

• If your scalp is prone to irritation, psoriasis, eczema, etc., choose a milder formula or consider avoiding relaxers.

• Always do a patch test.

Brand & Reputation

• Pick brands with good reviews, known safety standards, clear labeling

• Avoid shady or overly cheap products with ambiguous ingredient lists

Ingredient List

• Avoid relaxers with harmful additives (excess formaldehyde, unlisted “fragrance” chemicals)

• Prefer simpler lists you understand

Patch / Strand Test

• Apply a small amount to a patch of scalp or a strand 24 hours in advance

• See if any irritation, redness, burning appears

• Do a strand test to see result and timing

5. How to Apply a Hair Relaxer Safely

Getting the application right is essential. Below is a careful, step-by-step approach.

Pre-Application Prep

1. Wash hair a day before or 12 hours before (not same day). Use a mild shampoo with no conditioning.

2. Don’t use shampoo just before relaxing—you want your scalp to retain some natural oils to help protect it.

3. Detangle gently using a wide-tooth comb, from ends to roots.

4. Wear old clothes and protect your collar/neck.

5. Apply protective cream or petroleum jelly around hairline, ears, and neck to minimize chemical burn if it flows.

Sectioning

• Divide hair into 4–8 manageable sections, clip them.

• Always start applying from the back of the head or areas that process more slowly, leaving front for last.

Apply Relaxer

1. In one section, apply relaxer starting about ½ inch away from scalp (do not mix the scalp area at first).

2. Avoid touching already relaxed hair (don’t overlap), to prevent overprocessing.

3. After the relaxer has had time (half the processing time), you can gently “milk” it down the shaft if needed, but very carefully.

Timing & Monitoring

• Follow the maximum time indicated by instructions. Don’t overdo it.

• Watch hair texture in mirror. At some point strands begin to smooth.

• If burning, itching, or strong stinging occurs, rinse immediately.

Rinse & Neutralize

1. Rinse thoroughly with lukewarm water until product feels mostly gone.

2. Apply the neutralizer or neutralizing shampoo as directed. Leave it in for the full time.

3. Rinse again completely and gently.

Touch-Up Guidelines

• Only apply relaxer to new growth, not previously relaxed hair.

• Maintain safe intervals (see next section) to avoid overlapping relaxers.

6. How Often Should You Relax Hair?

Timing is critical. Too often, and hair becomes brittle. Too rare may lead to noticeable roots.

Growth Rate & Timing

• Hair grows about 0.5 to 1 inch per month on average (varies by person).

• Many stylists recommend 8 to 10 weeks between relaxer sessions. Some people stretch to 12 weeks depending on hair health and growth.

• If you have fast growth or a short haircut, you may need more frequent touch-ups—maybe every 6 to 8 weeks.

Risk of Overprocessing

• Applying relaxer too soon or overlapping onto previously relaxed hair causes breakage, thinning, or even bald spots.

• The hair is already weaker after one relaxer. Reapplying too quickly compounds damage.

Best Intervals

• For most, 8–10 weeks is the sweet spot.

• Some choose longer intervals to reduce stress on hair (e.g., 12 weeks), but hair texture and manageability must be considered.

7. Aftercare & Maintenance of Relaxed Hair

Once hair is relaxed, how you care for it determines whether it thrives or deteriorates.

Deep Conditioning

• Use a deep conditioning treatment at least once a week (or more if needed).

• Look for products with proteins (keratin, silk protein, etc.) but balance with moisture.

Protein vs Moisture Balance

Relaxed hair needs both protein (to rebuild strength) and moisture (to prevent dryness). Overdoing one can cause brittle hair or limp hair.

• Alternate between protein treatments and moisturizing masks.

• Monitor your hair: if it feels mushy → too much protein; if it feels limp or droopy → needs protein.

Gentle Handling & Protective Styles

• Use wide-tooth combs, detangle in sections, start from ends upward.

• Minimize heat styling. Use low heat and always apply heat protectants.

• Choose protective styles (braids, buns, twists) but avoid tight tension.

Leave-In Treatments, Oils & Moisturizers

• Use a light leave-in conditioner to seal moisture.

• Natural oils (coconut, argan, jojoba) can help seal ends but don’t replace water-based moisture.

• Trim split ends regularly.

Regular Trims & Maintenance

• Trim occasional split ends or brittle tips.

• Avoid harsh shampoos; use sulfate-free, gentle cleansers.

• Clarify occasionally (once a month) to remove buildup.

8. Damage, Side Effects & Risk Management

Relaxers can cause trouble if misused or overused. Knowing risks and signs helps you stop problems early.

Common Side Effects

• Scalp irritation, burns, redness

• Hair breakage or shedding

• Split ends or thinning

• Uneven texture

• Dandruff or flaking

Long-Term Risks & Scientific Findings

Recent research raises concerns beyond cosmetic damage:

• A review article noted that chemical hair relaxers are associated with fragility of the hair shaft, allergic contact dermatitis, and irritant contact dermatitis.

• Some epidemiological studies have found associations between heavy, frequent use of hair relaxers and uterine cancer in postmenopausal women.

• However, the evidence is not conclusive. Some reviews caution that the link is still debated, and confounding factors may exist.

• Relaxers may contain harsh chemicals such as formaldehyde, phthalates, or strong alkalis, which raise health concerns.

The point is: risk is not zero. Use with care, don’t overdo it, and pay attention to your body.

How to Detect Damage Early

• Hair feels brittle or snaps easily

• Excessive shedding

• Scalp pain or persistent irritation

• Thinning edges or bald patches

• Uneven or kinky regrowth patterns

If these appear, stop relaxing and let hair recover.

What to Do if Damage Happens

• Stop chemical treatments

• Use protein and reconstruct treatments

• Trim damaged parts

• Use gentle, hydrating hair care

• Seek professional help if scalp injury or severe damage occurs

9. Alternatives to Hair Relaxers

If you’re wary of the risks, or want to give your hair a break, several alternatives exist.

Keratin / Brazilian Treatments

These use milder chemicals to smooth hair, rather than completely break all bonds. Result is more relaxed curls—not fully straight hair. These treatments are sometimes safer but can still stress hair.

Heat Straightening

Using flat irons, blowouts, or hot combs gently (with protections) allows temporary straightening without permanent chemical change. But frequent heat also damages hair, so limit usage.

Texturizers / Loosening Treatments

These weaken curl just enough to make styling easier, without fully straightening. Some people prefer this middle ground.

Embracing Natural / Styling the Curls

Many choose to stop relaxing altogether, follow the “natural hair” path, and style curls with twist-outs, braids, wash-and-go, etc. This removes chemical stress and often leads to healthier hair in the long run.

10. My Experience / Case Example

I worked with a friend (let’s call her Aisha) who had very tight curls that were hard to manage. She used a lye relaxer at home without much guidance. Over a few years, she noticed breakage at the ends, thinning around her edges, and occasional scalp burning. She also had to visit salons often just to “fix” failed relaxer jobs.

When we switched to a gentler no-lye formula, spaced her relaxers to 10 weeks, used weekly protein & moisture treatments, and started doing protective styles, she saw improvement: fewer breakage issues, stronger hair, and better length retention.

The lesson: relaxers are a tool. But the way you use them, maintain your hair, and listen to your hair’s response makes all the difference.

11. FAQs

Q: Can you relax hair after coloring it?
A: It’s possible, but risky. Color weakens hair already. If you must, wait a few weeks, use gentle formulas, and do strand and patch tests first.

Q: Does relaxer ruin natural curl forever?
A: No. The relaxed portion remains straight until cut. New growth will be your natural curl. If you stop relaxing, over time the straight parts will be trimmed away.

Q: Can men use hair relaxers?
A: Yes. The same principles apply—careful formula choice, scalp protection, timing, and aftercare.

Q: Is it okay to relax edges / baby hairs only?
A: Many people try it, but edges are particularly fragile. It’s riskier, so go very gentle, use protective cream, reduce timing, and monitor closely.

Q: When should I stop relaxing permanently?
A: If you see signs of damage, thinning, scalp problems, or just want a healthier hair path. Many transition by gradually relaxing less or switching to natural styling.

Q: How do I pick a good brand?
A: Look for trusted brands, good reviews, clear labeling, with fewer harsh additives. Always patch test first.

12. Conclusion

Hair relaxers offer a way to transform texture, reduce styling time, and achieve straight or smoother hair. But they come with responsibilities. The difference between a successful relaxer job and a damaging one often lies not in the product itself but in how it’s used, what precedes and follows it (prep and aftercare), and how attuned you are to your scalp and hair’s signals.

Always choose a formula suited for your hair and scalp, follow careful application protocols, give your hair plenty of love afterward, and stay alert for warning signs. If you ever feel uneasy or see damage, pause and give your hair time to heal.

Whether you continue relaxing or choose an alternative route, the hair you have now deserves patience, respect, and care.