25% OFF for first-time customers. Use promo code NEW2S4

Attention Stylists & Salon Owners

With S4 you can give your clients BETTER results than other keratin treatments in HALF the chair time. No fumes. No dangerous chemicals. No special ventilation. No restrictions. Unlimited styling options. There are 4 formulas to choose from to meet each client's expectations.

Listen to this message from Stylist and Salon Owner, Dani Romano.

I've been working with all types of keratin for the past 10 years. When I first heard of S4 I was a little bit skeptical because I've worked with other formaldehyde free keratins that just were not effective. They didn't last more than a month or they didn't last at all. S4 delivers everything that it promises.

Dani Romano
Hair & More by Dani
Trumbull, CT

Before Treatment

After Treatment

After Treatment, Styled

Before Treatment

After Treatment

After Treatment, Styled

S4 smoothing products work on all hair types, making your clients' hair smoother, softer, straighter and more manageable.

More Styling Options

Unlike traditional salon keratin treatments, your client can go from straight to curly and back anytime.

S4 does not coat the hair like traditional formaldehyde-based keratin treatments or make the hair pin-straight like Japanese straighteners. Your client has unlimited options between treatments.


Try Our New FLAT IRON FREE Treatment

Smoothing treatment for ALL HAIR TYPES including BLEACHED, HIGHLIGHTED & DAMAGED hair/Slight to Extreme Frizz all without the use of a Flat Iron.

The latest addition to our product line is our FLAT IRON FREE treatment which provides the client with smoother, softer, more manageable hair that can be done in less than half the time of a traditional keratin treatment and lasts for month. It can be used on virtually any client who wants to reduce frizz and add luster and manageability but who does not want to lose much of their wave or curl. It’s a great choice for clients who have delicate or damaged hair since no flat iron is required.

Your client’s hair can be colored and highlighted immediately after their S4 smoothing treatment. This client’s hair received the S4 INFINITY Smoothing Formula followed by color and highlights.

Kudos to S4 for finally giving us stylists a smoothing treatment without harsh chemicals, no formaldehyde. It's safe for the salon, stylist and client. We love the product and we're making money in half the time.

Joy Fields
All About Joy
Palm Desert, CA


Before and after, using S4 smoothing treatment

Simple Step-by-step Instructions

The simple process delivers long lasting results to your client in half the time.

Apply easily & quickly. Takes less than 1/2 the time of traditional keratin treatments

Leave it on hair for 30 to 50 minutes.

Rinse and dry.

Flat iron. (except for Flat Iron Free formula)


Once in a great while, there truly is a breakthrough in our industry. S4 makes all other salon Keratin smoothing treatments obsolete.

Jim Morrison
Past president L’Oreal Salon Division

Want to try S4 with no risk? We'll send you enough to do 2-4 clients, delivered to you with shipping & handling included.



It’s smarter for the stylist as there are no toxic fumes. Zero formaldehyde in the product or in the air. Because it’s safer and faster, it’s ideal for the stylist working from home or in a small space.



Once you try S4, it will become your smoothing treatment of choice.



Shop Single Products

Plush Shampoo - 8 oz

Plush Shampoo - 32 oz

Plush Conditioner - 8 oz

Plush Conditioner - 32 oz

Smoothing Treatment - Flat Iron Free 8 oz

Styling Crème - 8 oz

Read What Professional Stylists Say About S4

S4 has been a complete game changer ...
Henri B., Mizu Salon, NYC

I have been doing keratin smoothing treatments since they first came out and many refer to me as the "Keratin King." I have also been the Director of Education for multiple major keratin brands. Unfortunately, I began to suffer medically from the effects of formaldehyde, so I refused to do them any longer. The great news is that I discovered S4 and it has been a complete game changer. Not only does S4 have no formaldehyde or produce any fumes, it's so much easier and faster to do and the results last as long or longer — and I'm making just as much $ as ever. My clients really like the results, and they keep on coming back for more. The quality of the hair is amazing after the S4 treatments. Now we all can get all the wonderful benefits of keratin smoothing without the risks! LOVE S4!

Henri Borday
Master Stylist, Mizu Salon, NYC

The easiest smoothing treatment I've ever done...Terri C., TLC for Me, Midlothian IL

Thank you so much for getting the product to me so quickly, I have to say that was the easiest smoothing treatment I think I’ve ever done. I love your products!

I am a mobile stylist. All of my services are done at the clients home. I did Brazilian blowout on my client before and we had the fans going and the windows open today and my eyes were still watering and I was still coughing. Today, with S4, it was nothing at all. Even the client said how much she liked the product.

Terri C.
TLC for Me, Midlothian IL

Your amazing product is blowing up my calendar...Nancy J., Shear Attitude, CA

This is by far the best Keratin treatment that I’ve ever used, hands down!

Nancy J
Shear Attitude, Newport Beach, CA

S4 has met & exceeded expectations ...
Joseph A., Salon Owner

I’ve served in this industry for over 50 years from the NE (mostly MD) to CA and now to South Florida, working with many manufacturers during my career as a professional stylist and salon owner. Throughout my tenure, I have never liked working with products containing formaldehyde or sodium hydroxide. In addition to these ingredients damaging and splitting the cuticle, (which will eventually work its way to the center of the medulla), the ill health effects are legendary. Result — not healthy for client or stylist & therefore, not an attractive solution.

But this amazing breakthrough in the industry with the S4 treatment has changed the venue totally. It is a fabulous Frizz Buster which leaves the hair with a silky, shiny, natural appearance. All my clients, no matter what the texture of their hair, find that S4 has met & exceeded expectations.

The application of S4 is simple, easy and produces fabulous results in less than an hour. All 3 formulas cover every client’s hair texture, so my clients are extremely pleased — and the price is right! The great news is that there are no nasty fumes, and the results are fantastic. You can also style & color immediately after application which is a win-win for everyone.

I am thoroughly impressed with all aspects of this product. In my opinion, S4 is a fashion forward breakthrough in the chemical services venue.

Joseph Amato
Master Design Artist, South Florida
National Haircutting Champion
Former Instructor at International Academy Hair Design
Salon Owner
Regional Design Artist for Sebastian
Rusk Master Design Artist

NO FUMES (I have asthma) during blowdry or flatironing ...
Heather R., Loft on Linden, NC

I just used the Exteme formula on my friend and WOW. Just the whole process, less time, easy application, NO FUMES (I have asthma) during blowdry or flatironing, the hair is silky, shiny! But not stick straight!!! Thank you for all your help. Cant wait to really get this going.

Heather R.
Hair Loft on Linden, Pinehurst, NC

They work amazingly on the clients...Ruth F., Beautifully Inspired Hair Studio, RI

The products are excellent. I use them in my salon and have great results.

Ruth F.
Beautifully Inspired Hair Studio, Woonsocket, RI

The styling creme is FANTASTIC!...Tish F., Sylver Salon, WI

Thank you! I am going to do a smoothing treatment on myself soon. I have however sold out of the 6 retail size styling cremes already! That product is FANTASTIC!

Tish F.
Sylver Salon, Bariboo, WI

The results are astounding ...
Lauren D., Pinned and Proper, NYC

As a high end Bridal and Celebrity Stylist, my clients' hair must be in the best condition prior to styling. I’m a perfectionist! I have tried every keratin smoothing treatment out there and S4 is my absolute favorite! Not only is it really fast and easy to do, but the results are astonishing and there are no fumes. The hair feels fantastic, looks so much healthier, and lasts longer than any other smoothing treatment I have tried. I am an advocate for healthy products and ingredients and S4 provides no risk to me or my clients. They have a few different options to choose from with different end results, so there's something for everyone. Trust me, I wouldn't DARE do this on my clients if it wasn't the best. Thank you S4!

Lauren Decosimo
Pinned and Proper, NYC​

I can do the treatment same day as color...
Joy F., All About Joy, CA

Thank you S4 for giving us stylists this awesome and SAFE line of keratin smoothing treatments at such great prices. I have been doing high end clients for many years as well as specializing in brides and their wedding parties and my clients come to me because of my attention to detail and my love for them and the health and beauty of their hair. Especially in these crazy times with the virus, my clients don't want to spend hours in the chair so this has been such a wonderful new product line that gives them incredible results, plus I can do the treatment the same day as I do their color which is HUGE. It truly works better than other smoothing treatments I've used in the past and my clients are thrilled and happy with the results and the condition of their hair. Also, the Styling Creme they offer is THE BOMB. So pleased with the entire line.

Joy Fields
All About Joy, Palm Desert, CA

Just tried this product and it is amazing ... Sandra A., VA

Just tried this product and it is amazing...great results!

Sandra A
Arlington, VA

My clients absolutely love it...Louis R., Do or Dye Hair Salon, IL

I’ve been a salon owner for 15 years. I deal with a lot of people of different ethnic backgrounds. I came across your product even though I’ve used countless others, none of them offered the ease of your product. I do lots of treatments for people with different textures and I have to say my clients I’ve used this on absolutely love it!!!

Louis Rodriguez
Do or Dye Hair Salon, Chicago, IL

Love how the hair feels!...Denise G., Bon Cheveux, NJ

My client had very frizzy hair from cancer treatments – then colored on top of Infinity. Thank you for your advice. We were both very happy. Love how the hair feels!

Denise G.
Bon Cheveux, Marmor, NJ

My clients love the new smoothing treatment...Masako I., SalonMONTE, VA

All my clients who were used to Brazilian blowouts/keratin love the new smoothing treatment. I needed to order more for my personal use since my families and friends love it also!

Masako I.
SalonMONTE, Alexandria, VA

More product please  — I'm thrilled... Sandy M., TX

I can’t tell you how thrilled I am about your product!!! We all love it! I definitely want to reorder a bigger amount now. Would you be kind enough to send me a purchase order form? FYI, I’ve told all my colleagues....🥰 Thank you, awesome product!

Sandy M.
Independent Stylist, Houston, TX

NO Odor, Minimal time to apply ... Sharon F., SalonMONTE, VA

We are passionate about this smoothing system. Immediately the hair is incredibly beautiful, shiny, manageable and SMOOTH. Our clients experience the FULL MONTE hair care service on their visit to the salon as well as home care support products. Our team is excited that this SMOOTHING system has NO Odor, Minimal time to apply, able to apply color to the hair immediately after the service. We are thrilled to receive any and all education available. Many thanks.

Sharon F.
Director, SalonMONTE, Alexandria, VA

UNBELIEVABLE. Highly recommend 💕...
Kimberly H, 50 Shades of Beauty, UT

Did this service yesterday on a client. UNBELIEVABLE. Highly recommend 💕

Kimberly H.
50 Shades of Beauty, W. Vallet, UT

I am obsessed!

I am obsessed with this keratin product. So glad I found this on Instagram. Firstly, I can’t believe this was on my doorstep within two days! Amazing! Secondly, it was extremely easy to do. I will continue to order this again and again and again. Thank you for an amazing product!

- CK

Each time I use it I fall more in love with this product!...Dani. R., Hair & More by Dani, CT

I am an independent stylist out of Fairfield County CT! I have been using S4 since January 2021 and each time I use it I fall more in love with this product!! Never have I ever felt so confident using a product on over processed blonde hair! But the Infinity has zero smell and leaves the hair softer and smoother than any other keratin I have ever used in my 13 years in the business! This customer has cystic fibrosis, and she was always concerned with the fumes that come with traditional keratin treatments but with S4 her and myself have such peace of mind our lungs are safe! Obsessed to say the least! I am so excited to be a part of your S4 family! You guys are changing the game! Thank you!!

Dani R.
Hair & More by Dani, Trumbull, CT

The conditioner smells sooo good...Mary Jo E., Hanford, CA

Hi, so I tried this new product and I LOVE it and the conditioner smells sooo good.

Mary Jo E.
Medeiros Spa & Salon, Hanford, CA


First use of Neem Oil for hair care dates back to the earliest of Sanskrit writings. It is currently being used in pharmaceutical research for its medicinal properties.

Our team has developed a proprietary blend using concentrated Abaco Neem Oil and other nutrients and botanicals to deliver a transformational long lasting result without any formaldehyde, or other toxic chemicals or high pH ingredients like those found in many keratin treatments, reverse perms, formaldehyde free smoothing treatments or relaxers. No masks or special ventilation is required.


4 Formulas to ensure the perfect treatment for each of your client’s needs

ALL HAIR TYPES including BLEACHED, HIGHLIGHTED & DAMAGED hair/Slight to Extreme Frizz

ALL HAIR TYPES including BLEACHED, HIGHLIGHTED & DAMAGED hair/Slight to Extreme Frizz

Normal, Color, Curly, Wavy, Medium Frizz (NOT for Bleached, Highlighted, or Heavily Damaged hair)

Resistant, Coarse, Virgin, Color, Curly, Wavy, Kinky, Medium Frizz (NOT for Bleached, Highlighted, or Heavily Damaged hair)

Money Back Guarantee
Buy any of our treatment packages and if after you try it on a client, you don’t think it is BETTER than your existing smoothing treatments, send it back anytime within 30 days of shipment for a refund of your purchase price, no questions asked.

You can get a refund even if a container is empty!
Made in USA