Relaxing Hair Safely: The Honest Guide to Relaxers and Aftercare
Relaxing hair means permanently breaking and reforming the disulphide bonds that give curly and coily hair its shape, using an alkaline cream. It is chemistry, not styling, and it cannot be undone: the only way back to your natural texture is growing it out. Done on a strict schedule by someone competent, with the right aftercare, relaxed hair can be strong and healthy. Done carelessly, it is the fastest route to breakage and traction damage in hair care.
Key takeaways
- Relaxing hair is permanent. New growth comes in at your natural texture, so you are committing to touch-ups roughly every 8 to 12 weeks.
- Only ever relax the new growth. Overlapping onto already-relaxed hair is the single biggest cause of breakage.
- Neutralising shampoo is not optional. It stops the chemical reaction, and skipping it keeps the hair processing.
- Relaxed hair needs protein and moisture in alternation. Too much of either causes breakage in opposite ways.
- Never relax hair that is already broken, or scalp that is scratched, sore or freshly washed.
What is actually happening when you are relaxing hair?
Hair keratin is held in shape partly by disulphide bonds, which are strong chemical links between sulphur atoms in the protein chains. The tighter the curl pattern, the more of these bonds sit in a configuration that holds the coil.
A relaxer is a strongly alkaline cream that swells the cuticle, penetrates the cortex and breaks a proportion of those bonds. While they are broken the hair is soft and malleable and can be combed straight. A neutralising shampoo then drops the pH sharply, halting the reaction and locking the new, straighter configuration in place.
Two consequences follow, and both are permanent. The bonds that were broken do not come back, so that section of hair is straight for life. And the hair is measurably weaker than it was, because you have removed some of its internal scaffolding. Research on hair care practices in women with textured hair consistently finds chemical relaxing among the practices most associated with damage, which is not an argument against relaxing so much as an argument for doing it properly and infrequently.
Which type of relaxer should you use?
| Type | Active | Strength and feel | Best for |
|---|---|---|---|
| Lye | Sodium hydroxide | Fastest and most effective. Higher risk of scalp irritation and burns | Salon use, experienced hands, coarse resistant hair |
| No-lye | Calcium or guanidine hydroxide | Gentler on the scalp but leaves mineral deposits that dry the hair over time | Sensitive scalps, most at-home kits |
| Thio | Ammonium thioglycolate | Different chemistry, often used for straightening systems rather than classic relaxers | Specialist salon work only |
The no-lye mineral build-up point matters and is widely under-explained. Calcium deposits accumulate on the shaft with each application and progressively dry the hair, which is why long-term no-lye users often report hair that feels increasingly brittle for no obvious reason. A chelating shampoo every few weeks is the answer.
Never mix systems. Applying a thio product over hydroxide-relaxed hair, or the other way round, can dissolve the hair. If you are switching, that is a salon conversation.
How do you do a touch-up without wrecking the lengths?
A touch-up is relaxing hair that has grown in since the last application, and only that. The rule is simple and almost everyone breaks it: the relaxer goes on the new growth, not over hair that is already processed. Overlapping applies the chemistry twice to the same fibre, and that is where hair snaps off at the demarcation line.
- Wait 8 to 12 weeks. Enough new growth to work with, not so much that the line is hard to see. Do not go by the calendar alone, go by how much has grown.
- Do not wash for at least three days. Natural scalp oil is protective and shampooing strips it. Do not scratch, and do not use a stiff brush.
- Base the scalp. Petroleum jelly or a proper base cream over the whole scalp, especially the hairline, nape and behind the ears.
- Protect the processed lengths. Coat the already-relaxed hair in conditioner so that any stray relaxer is buffered.
- Four sections, back first. The back is most resistant and the hairline is most fragile, so the hairline goes last and gets the least contact time.
- Watch the clock, not the mirror. Follow the timing on the product. Leaving it longer for straighter hair is how people get chemical burns and hair loss.
- Smooth, do not comb hard. Fingers or the back of a comb. The hair is at its most fragile right now.
- Rinse thoroughly, then neutralise properly. Two or three rounds of neutralising shampoo, until any colour indicator has cleared. This is the step that stops the chemistry.
- Deep condition immediately. A protein-containing conditioner while the cuticle is still settling.
Stop immediately if the scalp burns
A relaxer that stings sharply is causing a chemical burn, and a burn on the scalp can damage the follicle and cause hair loss in that patch. Rinse it out at once with cool water and neutralise. A relaxer done correctly should feel warm and tingly at most. If a salon tells you the burning is normal, that is the wrong salon.
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What aftercare does relaxed hair actually need?
Relaxed hair has less internal structure than it did, so it loses moisture faster and breaks more readily. The whole aftercare game is a balance between two things that both sound good and are both bad in excess.
Protein and moisture, in alternation
Protein temporarily patches gaps in the damaged cortex and makes hair feel firmer. Too much and the hair goes rigid and snaps. Moisture makes hair pliable and soft. Too much without protein and it goes limp, stretchy and mushy, which is called hygral fatigue.
A workable rhythm for most relaxed hair is a protein-containing deep conditioner every third or fourth wash, a moisturising deep conditioner in between, and a light leave-in daily. Adjust by feel: brittle and snapping means more moisture, limp and stretchy means more protein.
Condition Me® Hair Growth Conditioner £13.95
A daily conditioner built around breakage defence, with cholesterol, shea butter, glycerin and hydrolysed lupine protein. Cholesterol in particular is a familiar ingredient to anyone who has used a traditional post-relaxer conditioning routine. It improves slip so detangling snaps fewer hairs.
Masque Me® Repairing Hair Mask £24.95
A deeper weekly option for the days when the lengths feel dry and rough. Argan oil, provitamin B5 and hydrolysed lupine protein, for hair that is chemically processed and needs more than a rinse-out conditioner can give it.
Heat is the other half of the problem
Relaxed hair is often flat-ironed on top of being relaxed, and that combination is what turns manageable damage into breakage. If you take one thing from this section: always use a heat protectant, and drop your iron temperature. Most people run their straighteners far hotter than they need to on already-straightened hair.
Protect Me® Heat Protection Spray £13.95
A leave-in heat protection spray rated to 230 degrees, with niacinamide, panthenol and sunflower oil. On relaxed hair the case for it is stronger than on any other hair type, because the fibre has already spent some of its structural budget.
The nightly habits that quietly matter more
- Satin or silk pillowcase, or a bonnet. Cotton pulls moisture out and creates friction.
- Wide-tooth comb, ends first. Never a brush on wet relaxed hair.
- Loosen the styles. Tight braids, weaves and ponytails on relaxed hair are how traction alopecia starts, and the hairline does not always recover.
- Trim every 8 to 12 weeks. A split travels up the shaft. Cutting it costs you half an inch, ignoring it costs you three.
Who should not be relaxing hair at all?
Some situations make relaxing genuinely unsafe rather than merely inadvisable. Do not relax if:
- The scalp is broken, scratched, sore, inflamed or has any open area.
- The hair is already breaking, or you have visible thinning along the hairline or parting.
- The hair is bleached or highlighted. Two chemical processes on the same fibre is how hair dissolves.
- You have had a reaction to a relaxer before.
- It is a child. Textured hair on a child needs care, not chemistry, and the scalp is more vulnerable.
- You are unsure what was last used on the hair. Unknown chemistry plus new chemistry is a gamble with your hair as the stake.
If you have persistent scalp soreness, scaling, bald patches or hair loss along the hairline, see your GP rather than pressing on. Traction alopecia caught early is much more recoverable than traction alopecia left for two years.
How do you transition back to natural hair?
Because relaxing hair is permanent, transitioning means managing two textures on one head until the relaxed portion is gone. There are two routes.
The big chop cuts the relaxed hair off in one go, leaving natural hair only. It is quick, it removes the fragile demarcation line immediately, and it is a big aesthetic decision.
The long transition grows the natural hair out over a year or more, trimming the relaxed ends gradually. The demarcation line between the two textures is the weak point and is where breakage happens, so this route needs low-manipulation styles, generous conditioning and gentle detangling. Braid-outs, twist-outs and roller sets help by blending the two textures so you are not fighting them.
Please note. Watermans products are 100% cosmetic and do not treat medical hair loss. Individual results may vary.
Frequently Asked Questions
How often can I safely relax my hair?
Every 8 to 12 weeks, and only on new growth. More frequently than 8 weeks and you will inevitably overlap onto processed hair, which is what causes breakage at the demarcation line. Some people stretch to 14 or 16 weeks successfully, but the longer you leave it the more careful the detangling needs to be.
Is relaxing hair permanent?
Yes. The disulphide bonds broken during the process do not reform, so that section of hair stays straight until it is cut off. New growth arrives at your natural texture, which is why touch-ups exist. Anything sold as a temporary relaxer is a straightening treatment working by a different mechanism.
What is the difference between a relaxer and a keratin treatment?
A relaxer permanently breaks disulphide bonds with an alkaline cream and cannot be undone. A keratin smoothing service coats and seals the shaft, usually with heat, and washes out over a few months. They are not interchangeable and should not be layered without professional advice.
Can I colour relaxed hair?
Permanent colour and bleach on relaxed hair is high risk because both processes weaken the same structure. If you want both, leave at least two weeks between them, do the relaxer first, and consider a semi-permanent colour or a deposit-only gloss instead of bleach. Have a professional assess the hair first.
Why does my hair break at one specific point along the length?
That is the demarcation line, the boundary between relaxed hair and new growth, or between two overlapping applications. It is the weakest point on the fibre because the texture and the internal structure change abruptly there. Low manipulation, moisture and avoiding overlap are the fixes.
Do I really need the neutralising shampoo that comes in the box?
Yes, and using a normal shampoo instead is one of the most damaging shortcuts there is. The neutraliser drops the pH and stops the reaction. Without it the hair keeps processing after rinsing, which is exactly how people end up with hair that snaps a week later.
Is no-lye relaxer better for my hair?
It is gentler on the scalp, which is a real advantage if you are sensitive. It is not gentler on the hair over time, because calcium deposits build up on the shaft and progressively dry it out. Use a chelating shampoo regularly if you use no-lye.
Can relaxing hair cause hair loss?
A correctly applied relaxer should not. Chemical burns to the scalp can damage follicles, and repeated overlapping causes breakage that looks like hair loss but is snapping along the shaft. Persistent hairline loss with tight styling is traction alopecia, and that is worth seeing a GP about early.
The Short Version
Relaxing hair is a permanent chemical change, not a style, and the whole craft is in restraint. Touch up new growth only, every 8 to 12 weeks. Do not wash for three days beforehand, base the scalp properly, keep to the timing on the tube, and never let a burning scalp be talked into being normal. Neutralise thoroughly, then run an aftercare routine that alternates protein and moisture, protects against heat and keeps styles loose. If hair is bleached, broken, or the scalp is sore, do not relax it. Watermans makes vegan, UK-made cosmetic hair care and has sold over 5 million bottles since 2012, and our part in this is the aftercare, not the chemistry.
Looking after relaxed lengths? Start with Condition Me for slip and breakage defence, vegan and made in the UK.
Related reading: what to do when hair is coming away after a relaxer, the ingredients that genuinely strengthen hair, and how to match the repair to the actual cause of the damage.
Sources & References
- Ten pearls every dermatologist should know about the appropriate use of relaxers. Journal of Cosmetic Dermatology, 2017.
- Hair care practices and structural evaluation of scalp and hair shaft parameters in African American and Caucasian women. Journal of Cosmetic Dermatology, 2015.
- African hair length in a school population: a clue to disease pathogenesis? Journal of Cosmetic Dermatology, 2007.
- DermNet NZ. Traction alopecia.
- NHS. Hair loss: causes and when to see a GP.
- Martel JL. et al. Physiology, Hair. StatPearls, NCBI Bookshelf.
