Is Retin-A a prescription cream? Or does it come in other brand names? Don't seem to find anything that confirms what I'm looking for with a google search! Also Captain, what is the theory behind it potentially being of benefit? I'm using S5 at the moment, Nizoral and recently started 0.5mg of finasteride, and keeping an eye on how my body feels at the moment but something to try on my hairline could be useful. Also, what is your take on Azelaic Acid?
Retin-A is just one brand of the drug tretinoin (also known as all-
trans retinoic acid, the carboxylic acid form of Vitamin A). Renova is another common brand but there really is a large array of different brands as it is a pretty popular acne and photoaging treatment. It is prescription only but just like with finasteride you can simply order it online.
Tretinoin's benefit for hair loss is nothing new, it's used to increase absorption of topicals via its chemical exfoliant effect and even has been shown to regrow hair when used alone in 58% of patients (that's better than minoxidil's regrowth efficacy of 40%). More recently however it has also been shown to upregulate the prostaglandin-E synthase enzyme which leads to increased PGE2 levels (good for hair growth) in an
in vitro study.
Another
in vivo study also showed that tretinoin downregulates androgen receptor expression. Think less androgen receptors being synthesised = less targets for DHT.
In addition, some tentative evidence has also shown that tretinoin induces various growth factors in the areas that it's applied as well, think derma-rolling type benefits without the risks, this may also explain its efficacy in stimulating hair regrowth and increasing collagen synthesis in the skin. So you get a lot to love with tretinoin basically, especially if you're concomitantly applying it to your face as well, since it's one of the best studied retinoids in the use against photoaging.
As for azelaic acid, I don't recommend it simply because not only are there no human trials done on it but also there are no
in vivo trials. The only trials performed was one
in vitro study that even stated in its conclusion that a more appropriate
in vivo study was needed to confirm the evidence. I question this study because it also showed that zinc was shown to be a 5AR inhibitor yet you don't see anyone using topical or oral zinc to treat their Androgenetic Alopecia, at least not with good efficacy. Azelaic acid may hold promise for alopecia areata as shown in other studies and it may very well be a decent minoxidil absorption enhancer but I see no reason to use it. If you want to increase the absorption of your topicals, use tretinoin instead, simply because it has more additive benefit.
References:
http://www.ncbi.nlm.nih.gov/pubmed/22204820
http://www.ncbi.nlm.nih.gov/pubmed/3771854
http://www.ncbi.nlm.nih.gov/pubmed/25112173
http://www.ncbi.nlm.nih.gov/pubmed/3207614
http://www.ncbi.nlm.nih.gov/pubmed/11176716
http://www.ncbi.nlm.nih.gov/pubmed/8874749
http://www.ncbi.nlm.nih.gov/pubmed/14609562
