Stemoxydine 5 vs Minoxidil vs Aminexil | Comparing Hair Loss Ingredients



There are numerous products on the market intended for hair loss treatment. Many of them have completely different key ingredients. This makes it difficult to choose the right products.  We very often received questions from our customers asking our thoughts on Stemoxydine and Aminexil. Here we are going to briefly examine these two ingredients in comparison with the gold standard Minoxidil.


Structure Comparison:

The structures of these three chemicals are shown in the main image of this blog (see above). As shown, Aminexil has similar structure of minoxidil, with the piperidinyl group missing. Stemoxydine  has a completely different structure from minoxidil. Stemoxydine's IUPAC name is Diethyl pyridine-2,4-dicarboxylate ( see its molecular modeling image blow).


Do They Really work?

Minoxidil: Minoxidil has been proven to regrow hair on the top of the head. It is the only FDA approved and most widely used ingredient in hair regrowth products as of today. It was first used as an oral drug to lower blood pressure. It was soon found to stimulate hair growth. Rigorous clinical studies have confirmed this “side effect” and its FDA approvals for hair re-growth as topical solutions were granted. Clinical studies have shown that higher minoxidil concentration is more effective than lower minoxidil concentration in stimulating hair regrowth.  If you are interested in knowing more about minoxidil, you can read our blog: Minoxidil Frequently Asked Questions or Minoxidil | Professional Review.

Stemoxydine: Stemoxydine is a patented chemical by L'Oreal for hair regrowth and is used in its product “Kérastase Densifique” recently. L'Oreal claims that the liquid “Kérastase Densifique”, when applied to the roots, can promote the growth of more than 1500 new hairs in 90 days.  The study was conducted in a double blind vs placebo study consisting of 101 men between 18 and 55 years old. During the study, subjects applied stemoxydine 5% solution (aka, stemoxydine 5) once a day (6ml).

Stemoxydine has not yet been widely studied for hair loss treatment. The cosmetic group L'Oreal has designed and patented this product to be used topically.  The  stem cells are influenced and regulated  by creating hypoxia.  This seems to awaken dormant stem cells and produces increase numbers of follicles and also increased density.  L'Oreal controls all studies and also all distribution of this product.  The studies that L'Oreal has performed are on their website. There seems to be no danger in using this product except maybe to your purse.

It appears from early and limited in vivo studies that a small amount of hair regrowth did occur.  However, larger scale clinical testing would be needed to determine a more accurate assessment of the product’s success rate. 

L'Oreal used to have hair growth product based on Aminexil. Now Aminexil is all replaced by Stemoxydine in all of L'Oreal products. Does it mean Stemoxydine works better than Aminexil? We do not know. Sometimes a company makes a change not because the new product is better than the old one. Instead, it could be the new product gives them the exclusive ownership the formulation so nobody else can copy it, or it might be due to regulation related reasons. The bottom line is that this is a relatively new product, so only time will tell if there product really work.


Aminexil is another patented chemical molecule developed by L’Oreal. It was used prior to Stemoxydine but recently got ditched by L'Oreal.  L'Oreal claimed that Aminexil help prevent perifollicular fibrosis (scarring of the hair follicles) and therefore help treatment for hair loss. Aminexil had been pushed by L"Oreal for more than 15 years. Yet not so many people have heard about it. You got it, that must means something.

Aminexil is said to work in a similar way to the proven hair loss treatment minoxidil. However, aminexil is often mixed with minoxidil. There are very few products containing Aminexil without minoxidil. Yes, this is another hint if Aminexil really works.



We do not believe either Stemoxyldine or Aminexil comes close to the effectiveness of minoxidil in stimulating hair regrowth. Aminexil is dead now. Even the creator of this compound has dropped it, so should you. If it works, it most likely due to the presence of minoxidil in the same product.  If you are allergic to minoxidil itself, you can give Stemoxyldine a try. Please be advised that majority of people who are allergic to minoxidil products are actually allergic to the solvent (Propylene glycol), not minoxidil itself. Thus, they can use propylene glycol free minoxidil products like Dualgen-15 NO PG Plus, or Dualgen-15 NO PG to avoid any allergy reaction from regular minoxidil products.