Japanese Straightening vs Keratin Treatment: Which One Is Right for Your Hair?
MOMO HAIR · 2026-11-08
If you are tired of frizz or curls you have to fight every morning, you have probably seen two options: Japanese straightening and keratin treatment. They sound similar, but they do very different things. Here is a plain comparison from MOMO HAIR, our salon at Yonge and Eglinton in Toronto, so you can choose the right one.
The short answer
- Japanese straightening makes hair permanently straight. The treated hair stays straight until it grows out and is cut off.
- A keratin treatment smooths frizz and softens curl for a few months, then it washes out and your natural texture comes back.
If you want straight hair every day with no flat iron, Japanese straightening is usually the better fit. If you want less frizz for a season and want your curls back later, keratin may suit you.
Side by side
| Japanese straightening | Keratin treatment | |
|---|---|---|
| What it does | Changes the hair's shape from the inside | Coats and smooths the outside of the hair |
| Result | Straight, sleek hair | Smoother, less frizzy hair; curls are softened, not gone |
| How long it lasts | Permanent on treated hair; touch up the roots | Usually about 2 to 5 months, then washes out |
| Going back to your natural texture | Only by growing it out | Happens on its own as it washes out |
| Appointment time | About 3 to 5 hours | About 2 to 4 hours |
| Typical Toronto price | From about $200 to $300 (MOMO HAIR from $450) | About $250 to $380 |
How does Japanese straightening work?
A solution softens the bonds inside each hair that create the wave or curl. The stylist flat-irons the hair straight, slowly and in small sections, then a neutralizer sets the new straight shape. Because the change happens inside the hair, it does not wash out. New growth comes in with your natural texture, so you touch up only the roots, usually every six months to a year. You can read about cost and aftercare in our guide to Japanese hair straightening in Toronto.
How does a keratin treatment work?
A keratin treatment is painted onto the hair and sealed in with a flat iron. It coats the outside of the hair, which makes it smoother, shinier and less frizzy. It loosens curls but usually does not make curly hair fully straight. Every wash removes a little of it, so it slowly fades over a few months.
Is one safer than the other?
Both are professional chemical services, and both need a trained stylist.
With keratin and "Brazilian" smoothing treatments, the main concern has been formaldehyde. In 2011, Health Canada warned that several professional hair-smoothing solutions sold in Canada contained formaldehyde above the allowed limit, and some products labelled "formaldehyde-free" were found to release it when heated. If you choose keratin, ask your salon exactly which product they use and whether it releases formaldehyde.
With Japanese straightening, the main risk is damage if the hair is not suited to it or the work is rushed. Heavily bleached or already-relaxed hair may not be able to take it safely. That is why we always check your hair first and do a free 5-minute strand test on coloured or treated hair.
Which one works on very curly or coily hair?
Keratin can soften and smooth coily hair for a while, but it usually won't make it straight. Japanese straightening can make very curly and coily hair (types 3 and 4) straight, but it takes an experienced stylist and a careful assessment of your hair's health. We straighten curly and coily hair regularly. You can see examples in our straightening gallery.
Which costs less over a year?
A keratin treatment often costs less per visit, but it fades in a few months, so many people repeat it 3 or 4 times a year. Japanese straightening costs more up front, but the treated hair stays straight, and you only touch up the roots once or twice a year. Over a full year, the cost can end up closer than it first looks.
At MOMO HAIR, a first full Japanese straightening starts at $450, and a root touch-up around six months later is $350. Our straightening is done by Claire, our specialist with 20 years of experience, and our Director Liz has 28 years. That is above many Toronto salons, but our clients are very happy with their results, as our reviews show. Straightening is chemical work, and fixing hair that was damaged by a rushed treatment usually costs much more than doing it right once.
How to decide
Ask yourself three questions:
- Do I want straight, or just less frizz? Straight means Japanese straightening. Less frizz can be keratin.
- Do I want my curls back later? If yes, keratin. If you never want to fight your curls again, Japanese straightening.
- Is my hair bleached or relaxed? Then get a professional opinion first, because some options may not be safe for your hair.
Get an honest opinion
Our free consultation is the easiest way to decide. Come in with your hair natural, not blow-dried, so we can see your real texture. We will tell you what will work for your hair, what won't, and the exact price. Book online or call (647) 381-1398. We are on the 2nd floor at 2156 Yonge St, just south of Eglinton.