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  • Stella Lee

Review - L'Oréal Professionnel Serioxyl System

Updated: Jul 13, 2020

If you have been following my blog, you would know that I have had postpartum (post-pregnancy) hair loss. At this stage my hair loss has stopped (thanks to HIF Growth Support) and I am looking to further build up my hair density. I was very excited when Beautyheaven invited me to the L'Oréal Professionnel Serioxyl trial - an anti-thinning haircare system.

Active ingredient: 5% Stemoxydine

Stemoxydine is a molecule patented by L'Oréal. In the simplest terms, Stemoxydine is believed to create a hypoxic environment which would stimulate a specific kind of stem cells near the skin surface. Those stem cells are in turn responsible for new hair growth. So far there is only one clinical study supporting that Stemoxydine may increase hair density - by an average of 4% - after using it everyday for 3 month. The study was, surprise surprise, commissioned by L'Oréal, It doesn't mean that it can't be trusted - it just means that Stemoxydine hasn't been extensively tested.

Before I go into each of these products, there are two important things to note about this system.

First. The shampoo and conditioner do not contain the active ingredient Stemoxydine. They do not contain any other ingredient to stimulate hair follicles. If you already have shampoo and conditioner that you like, you may want to stick with them.

Second. A set amount of the denser hair gelée ("step 3" serum) needs to be applied every day for 3 months. One bottle lasts just over 3 weeks. To finish one course which is 3 months, you would need to use between 3-4 bottles. So your investment to try even just the serum will turn out to be much more than $61 (which is the price of one bottle).

Clarifying shampoo

The shampoo is a light blue-coloured thin gel which lathers up quite nicely. It rinses off completely clean but it does not feel harsh on hair. Even I shampoo daily, some days I feel I need to double cleanse to get rid of all the residue of the serum (step 3) from the previous day. I use 2-3 pumps on my shoulder-blade length hair.

Despite containing both sodium laureth sulfate and sodum laural sulfate, the shampoo is surprisingly safe for my coloured hair.

One bottled lasted for approximately 2 months (when used daily).

Bodifying conditioner

The conditioner is a light blue-coloured thin lotion. It feels thinner than most conditioners I have used, so I need to use quite a lot (about a 50c piece) on my hair. Again, it rinses off without residue. It does not weigh hair down, but it is not nourishing enough for my hair. Once to twice a week I top up with a hair treatment mask.

One bottled lasted for approximately 1.5 months (used daily).

Both the shampoo and conditioner contain peppermint oil and menthol, giving a cooling effect on the scalp.

The shampoo and conditioner combo makes my hair very soft. My hair is lovely to touch, even after just a week. At the same time, my hair feels more vulnerable. There may be a little more hair breakage in the shower, but not at a level that I am concerned about.

Denser hair gelée

This is the key product with the active ingredient Stemoxydine. This serum is quite a thin gel which does not feel sticky on the scalp. Four pipettes worth of product needs to be massaged onto dry or towel-dried scalp every day. For two reasons I would only use this on a damp scalp and hair.

  • Alcohol denat. is the first and main ingredient in this serum (see a full ingredients list at the end of this post). When I used it on dry scalp, the effect of alcohol was strong - my scalp immediately felt the heat; and at the end of the day, my scalp might even feel slightly itchy. Note that alcohol denat. can be drying or irritating for some people.

  • When I used the serum on dry scalp, it took longer for it to dry properly. My hair looked like it has got hair product stuck on it which has not been distributed evenly - it made me think of those guys I saw on the train who wack on their hair gel in a rush - if you see what I mean.

Results? I was given 3 bottles which was enough for 2.5 months. I really persisted but I just could not find any new, short hair near where I have been applying the serum. In hindsight, given that the L'Oréal study shows that hair density was increased by approximately 4% (that is, 4 new hair in an area of 100 existing hair), I doubt that the result would be at all noticeable, even if it had worked.


Unfortunately the Serioxyl system did not quite work for me. For now I am going back to my HIF.

Ingredients of denser hair gelée

Alcohol denat., water, diethyllutidinate, glycerine, ammonium polyacryloyldimethyl taurate, ethyl ester of PVM/MA copolymer, sodium chloride, t-butyl alcohol, linalool, geraniol, citronellol, benzyl salicylate, benzyl alcohol, limonene, fragrance.


About me

Makeup artist and hair stylist based in Sydney. Founder of the well-known award-winning bridal specialist team Faces Makeup and Hair. Beauty junkie with an obsession for skincare.

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