L'Oréal Professionnel
Serie Expert
Keratin Alpha Sleek Smooth Transformer

Keratin Alpha Sleek Smooth Transformer is rated 4.6 out of 5 by 27.
  • y_2026, m_6, d_8, h_13
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.46
  • cp_2, bvpage2n
  • co_hasreviews, tv_3, tr_24
  • loc_en_US, sid_loreal-professionnel-keratin-alpha-sleek-smooth-transformer, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_saloncentric
  • bvseo_sdk, dw_cartridge, 17.1.0, p_sdk_3.2.0
  • CLOUD, getAggregateRating, 44ms
  • reviews, product
Keratin Alpha Sleek Smooth Transformer
Preview image 1 of Keratin Alpha Sleek Smooth Transformer
watch the product video
Select Size
Available options to select
6.76 oz.
#E4563900
Auto Replenish:
FREE SHIPPING OVER $50 & EARN 100 PROREWARDS POINTS
  • Choose your frequency. Skip or cancel anytime.
  • Free shipping over $50* & 100 ProRewards Points++ on all recurring orders.
  • Select auto-delivery in cart.
  • Exclusions apply.
Learn More
Purchase Options
Find in-store availability
saloncentric credit card take charge Learn More

What It Is

A professional-grade, semi-permanent smoothing treatment mask that transforms hair for up two weeks of unparalleled smoothness, shine, and frizz control.

What It Does

• Smooths and controls frizz for up to 2 weeks.*

• 6x smoother hair**

• 77% more shine***

• Long-lasting frizz & volume control

• Faster smooth styling****

• Suitable for all hair types, even color or keratin-treated

 

*after 4 weekly uses of Smooth Transformer

**Smooth Transformer vs. before application

***vs. unwashed hair

**** vs. non-conditioning shampoo when using flat iron

What Else You Need to Know

This professional smoothing treatment is formulated with Keratin-Alpha Shaper and amino-acid chains to deliver salon-quality results. This is a breakthrough hybrid of texture and hair care. Contrary to classic conditioners or masks, it deeply penetrates inside the fiber and smoothes the hair at the keratin alpha level, the deepest level of hair. It is free from alcohol and artificial colorants, and suitable for all hair types including keratin-and color-treated. It is safe to use during a color appointment.

 

Note: This product has a technical smell due to a small amount of cysteine in the formula, which supports the anti-frizz, smoothing benefit.

1. Progessive treatment, use once a week after shampooing. Alternate with a hair mask on other wash days.

2. Shake the bottle well before use.

3. Section hair into two parts and apply evenly from lengths to ends on each section. Use 1 - 1.75 ounces, depending on hair thickness and length.

4. Leave on for 10–15 minutes, and then rinse thoroughly.

5. To activate the smoothing technology, blow-dry completely and use a flat iron. Use weekly for 4 uses, then once a month to sustain the frizz-control. Stop using if the hair feels dry.

AQUA / WATER / EAU • CETEARYL ALCOHOL • COCOS NUCIFERA OIL / COCONUT OIL • BEHENTRIMONIUM CHLORIDE • ISONONYL ISONONANOATE • CETYL ESTERS • PARFUM / FRAGRANCE • ETHANOLAMINE • ISOPROPYL ALCOHOL • CYSTEINE • DIMETHICONE • HYDROXYETHYLCELLULOSE • PHENOXYETHANOL • SODIUM METABISULFITE • AMODIMETHICONE • ASCORBIC ACID • TRIDECETH-10 • TRISODIUM ETHYLENEDIAMINE DISUCCINATE • PEG-100 STEARATE • ROSE KETONES • STEARETH-6 • TAURINE • TRIDECETH-3 • GLYCERIN • BUTYLENE GLYCOL • DISODIUM PHOSPHATE • ACETIC ACID • POLYSORBATE 60 • SODIUM PHOSPHATE • CARBOMER • SODIUM LACTATE • POLYSORBATE 20 • PALMITOYL TRIPEPTIDE-1 • PALMITOYL TETRAPEPTIDE-7

Purchases made in SalonCentric stores may be returned to any SalonCentric store. Purchases made through SalonCentric Customer Service, SalonCentric Business Partners, and SalonCentric.com orders Sold and Shipped by SalonCentric may be returned to a SalonCentric store; however, the return must not exceed $450 and must include the original receipt, packing slip, or invoice. For returns in-store of online orders, the refund will be credited back to the original payment method once the return has been processed. For SalonCentric.com Online Exclusive orders sold and shipped by third-party sellers, please see more details linked below for return steps.

The SalonCentric return policy does not currently apply to Kérastase & Shu Uemura purchases. Kérastase & Shu Uemura do not accept returns.

Click to see more details.

Rated 5 out of 5 by from Keratin Alpha Sleek Smooth Transformer It helped leave the hair smooth, silky, and much easier to manage. It’s great for reducing frizz, speeding up blow dry time, and giving the hair that nice finish without feeling heavy or greasy.
Date published: 2026-05-29
Rated 5 out of 5 by from Amazing always look for products that will preserve my hair color and benefit my hair. This conditioner does that perfectly it does phenomenal job at making my hair look amazing! This line of shampoo and conditioner is just that does everything you need and could ever want. When I rise the matching shampoo from the line and leave this conditioner in for 3-5 minutes, and combing it through using a large shower. My hair feels so silky and smooth. I was amazed. Once dried it looked amazing! It looked voluminous with fully of body. It’s how I always wanted my hair to look but was never able to achieve. It’s a fantastic conditioner that’s make for fine, thin hair like mine. I highly recommend it!
Date published: 2026-05-28
Rated 5 out of 5 by from If you have coarse frizzy hair, you need this! The new L’Oréal Keratin Alpha Sleek Anti-Frizz System is my absolute favorite for my thick coarse hair! It makes my hair so smooth and actually silky for the first time in my life! Didn’t make my hair feel greasy or heavy and was able to withstand the humid weather we’ve had lately. I am really impressed. The only complaint, that won’t keep me from using it though, is the smell is a little stinky but after you dry your hair, I don’t think I can even smell it anymore.
Date published: 2026-05-27
Rated 5 out of 5 by from L’Oréal Professional Keratin Alpha Sleek Smooth Transformer is excellent for taming frizz and creating a smooth, polished finish. It helps control flyaways while leaving hair soft, silky, and manageable without feeling greasy. I noticed my hair looked shinier and stayed smoother for longer, even in humidity. A great styling product for achieving sleek, salon-like results at home.
Date published: 2026-05-27
Rated 5 out of 5 by from Gave my dull hair more shine L’Oréal sent me this free sample through the Bzzagent sampling program in exchange for my honest review. This product is only meant to be used once a week for 15 minutes. It is best to use when you have time to spare since this isn’t a quick treatment. The formula is thick creamy. When applying I section my hair into 2 and apply the product evenly in my strands. It has a chemical smell to it that reminds me of a hair relaxer. After use this treatment gave my dull hair more shine and made it look healthier.
Date published: 2026-05-26
Rated 4 out of 5 by from Pretty good This really does live up to the name and transforms your hair! Perfect for anyone with dry hair or frizz. Don’t love the smell though
Date published: 2026-05-25
Rated 3 out of 5 by from Wouldn't try again Does the job but leaves ur hair smelling bad like a perm
Date published: 2026-05-25
Rated 4 out of 5 by from It’s just not me or my clients. Was not impressed. I love that everyone loves it and it gets great reviews. Maybe I’m old school, but this smooth transformer did not impress me.
Date published: 2026-05-24
Rated 4 out of 5 by from Hate the smell! Giving this product 4 stars instead of 5 simply because of the smell. The product works great! But the smell is horrendous! THANKFULLY the smell does not linger on the hair after styling.
Date published: 2026-05-24
Rated 5 out of 5 by from Love it! A great way to help keep the hair smooth longer with little effort. I definitely noticed a change in my hair after the transformer.
Date published: 2026-05-24
Rated 5 out of 5 by from Transforms This really does live up to the name and transforms your hair! Perfect for anyone with dry hair or frizz.
Date published: 2026-05-23
Rated 5 out of 5 by from L’Oréal Keratin Alpha Sleek I used this product for the first time this week. It rained on two of the days and I couldn’t believe how little frizz I had. I’ve used so many products that state frizz control and they never live up to the claim. The product does have a slight chemical smell and you have to leave on for 15 minutes. That’s the only complaint I have and it’s not a big problem.
Date published: 2026-05-22
Rated 5 out of 5 by from Amazing! As a hairstylist, I’m always looking for products that help smooth the hair without making it feel stiff or overloaded, and this one did exactly that. I used it during a blowout on a client with thick, frizz-prone hair and the difference was noticeable right away. The hair felt silky, looked much more polished, and had a smooth finish without losing movement. I also liked that it helped control flyaways while still keeping the hair soft and lightweight. It layered well with other styling products and gave the overall style a really healthy-looking shine. Definitely a nice addition for anyone wanting a sleeker finish without heavy buildup. I received this product free for my honest review.
Date published: 2026-05-21
Rated 5 out of 5 by from sleek all the way fantastic smell, texture, and made my hair silky smooth! feels very upscale and high end and left my hair beautiful, smooth, and not that weighed down feeling.
Date published: 2026-05-19
Rated 5 out of 5 by from L’Oréal Professionnel Keratin Alpha Sleek Smooth This is honestly the star of the lineup. The texture is rich but not heavy, and it makes hair look instantly polished and expensive. It smooths flyaways, helps tame puffiness, and leaves the hair incredibly soft with a glossy finish. Blowouts come out straighter and last longer, especially in humidity. It gives that “I just left the salon” smoothness.
Date published: 2026-05-18
Rated 5 out of 5 by from L’Oréal I used with my customers and the hair last for 2 weeks straight
Date published: 2026-05-10
  • y_2026, m_6, d_8, h_13
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.46
  • cp_2, bvpage2n
  • co_hasreviews, tv_3, tr_24
  • loc_en_US, sid_loreal-professionnel-keratin-alpha-sleek-smooth-transformer, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_saloncentric
  • bvseo_sdk, dw_cartridge, 17.1.0, p_sdk_3.2.0
  • CLOUD, getReviews, 9ms
  • reviews, product