Great shampoo, but my hair easily gets used to shampoos and then I have to change them. I used it for about eight months and it was perfect

This is a very dense and thick shampoo. Try to use half of the quantity you usually apply with other shampoos and it will do the job perfectly. It is very gentle with the hair and leaves a nice feeling after washing.

I have been using it for 5 months now and it has helped me a lot with hair damaged from dye and highlights. I use the entire Olaplex range and all the products are amazing.

Very good, it really made a difference to my hair which was dry and damaged from highlights and nothing like the mud that I saw it being compared to in other reviews! You just need a small amount (even though I have long hair) and after you apply it to your hair, add some water with the shower... I also got the mask from the same line which is also amazing. They are not particularly expensive, especially if you buy the liter bottles which last a long time. I will definitely buy them again

I have blonde hair from highlights.
I feel like I'm washing my hair with mud every time... it has a muddy texture... my hair gets oily even faster and feels weighed down.

The product is just fine, but you need to buy the rest of the products in the series for it to work. My hair is gray without dye and it is in better condition than before, but it doesn't work miracles either.

Good, cleans well, only a small amount is needed. Much better than the supermarket ones, quality-wise of course. You definitely need conditioner at the end, preferably from the same brand. When you straighten your hair, it lasts and makes it stronger.

I expected much more from this shampoo. I have fine blonde hair with balayage, it makes my hair quite oily without moisturizing it! The only good thing is that it requires a small amount.

The best shampoo ever!
I have blonde hair but not damaged thanks to Olaplex! I have the whole line for years... everyone tells me how wonderful my hair is! And all of this thanks to Olaplex. I have tried many well-known hair care products in the past

Expensive but worth it. You wash your hair fewer times a week, so you use less product. I also saw a huge difference in my hair, which because I mistreat it a lot needed to be cut for split ends three times a year. I used these shampoos and conditioners and only needed to cut it once. For me, they worked great

It is very good! It does what it promises!
This time I bought another well-known brand, as my hair is very damaged and I wanted to try something more "advertised". However, I believe that I will buy Olaplex again!

Honestly, the worst thing I have ever tried! Hair like mud, greasy and unimaginable dryness, which I have never had before!

It is suitable for all hair types and with a small amount, you can wash a lot of hair. The price is the only negative aspect.

The first sulfate-free shampoo that I try after reading about their benefits for a long time. I didn't expect it to make much of a difference, but after the first week of use, I saw results both in my hair and even more so on my scalp.

Only the scent is worth it. Otherwise, I wasted my money. Not to mention the quantity. Pure deception.

The shampoo is garbage, it caused hair loss even though I didn't immediately realize it was from the shampoo. I didn't have any other issues like stress or poor diet, and it also leaves the hair very wild

The packaging is very small for its price, especially if you have long hair like me, it finishes quickly, although the shampoo in the series foams a lot! Overall, overrated, personally I didn't see any difference in my hair.

If you choose not to buy a product again as soon as it finishes, it means something. I don't know if it does what it promises... at least on my hair. Maybe it's overpriced.

Disappointing product, I had to throw it away after 2 weeks of use. It leaves the hair very dry, to such an extent that it damaged the ends (and we're talking about a healthy, freshly cut hair). Only Kerastase, in my opinion, for professional care.

I had an allergic reaction. I was itching a lot and developed redness on my throat. It took me a month to figure out which product was causing it. As soon as I stopped using it, the symptoms disappeared. I don't understand why it is heavily advertised despite causing allergies. It was mediocre as a supermarket-type product.

Very good shampoo, you need a small amount. It is quite expensive so I usually only use it as a second choice. Its scent is subtle and high-quality and it leaves the hair very soft. I would buy it again, although not immediately after finishing the bottle.

Amazing! It moisturizes damaged hair and leaves it soft. I haven't tried anything better, although I have tried many.

Although I love number 3 and have been using it at least once a week for years, I did not like the shampoo at all. The only difference I noticed is that it cancels out all the good things about number 3, it makes my hair wild and dries it out...

I have been using it for 10 months. It is the only shampoo that managed to keep my hair from getting oily for 2 days, while other shampoos would only keep it good for a maximum of 12 hours. It is the second bottle I am buying as it doesn't require a large amount (I have straight and long hair), it foams a lot with a small amount of product and leaves the hair lightweight, completely different from other products I used. I highly recommend it!

Very harsh shampoo, I was patient in case my hair needed time to get used to it but no. It cleaned well but only for 1 day, it made my hair hard and gave me dry scalp. It's not worth the money at all.

It does exactly the opposite of what it promises. From the very first use, I noticed wild hair, but some particular products need a few uses for the area to get used to them. Encouraged by this and mainly by the positive "reviews" and making the mistake of ignoring the negative ones, I continued to use it. After a month of use, the result is dull, dry, weak hair that falls and breaks easily.

The best shampoo I have ever put on my hair. Unbelievable softness and shine! With a small amount and a little massage on the head, it foams a lot! It does not contain sulfates and it also protects the color of the hair! I think I found my shampoo. Even if it was more expensive, I would buy it again and again. I have already ordered more before it runs out. Of course, use conditioner as well and you will see exactly what I'm talking about!

Perhaps the worst shampoo I have ever used. It dehydrated my hair, made it extremely frizzy, and made it look like it had been burned. I believe that even the last shampoo from the supermarket would not have had such a bad result.
Unacceptable product at an outrageous price. The shampoo is simply TERRIBLE and unfortunately there are other reviews that confirm it.

Amazing results really. I had very dry, damaged hair with intense frizz, from the first use their appearance changed

The Olaplex No.4 shampoo left my hair dry and brittle as if it had been damaged from long-term use of a hairdryer, which I never use. My hair was frizzy and lost its shape after washing. I tried to restore it with masks at home and at the salon, but the result never changed.