Hair Loss: Azelaic Acid
acid (pronounced az-uh-LAY-ic) is a simple molecule ( HOOC(CH2)7COOH,
CAS Number 123-99-9, also known as 1,9-Nonanedioic acid) that is found
in some whole grains and in trace amounts in human bodies. Although it
is an acid, it is an extremely weak acid - much weaker than vinegar.
It's current use in medicine is in Azelex or Skinoren, which is a cream
base containing azelaic acid as 20% of its weight. Azelex is available
by prescription in the USA and is used in the treatment of acne.
Skinoren is available outside USA.
Azelaic acid may be useful as a hair growth stimulant. A research report
by Stamatiadis in 1988 suggested that azelaic acid (and combinations of
it and zinc ion and vitamin B6) was a strong type I 5-alpha reductase
(5-AR) inhibitor. The enzyme 5-AR (both types I and II) convert
testosterone to dihydrotestosterone (DHT). DHT has been shown to
contribute to male prostate enlargement (benign prostatic hyperplasia,
BPH) and to damage hair follicles.
Abstract of Stamatiadis' 1988 study:
Br J Dermatol 1988 Nov;119(5):627-632 Inhibition of 5 alpha-reductase
activity in human skin by zinc and azelaic acid.
Stamatiadis D, Bulteau-Portois MC, Mowszowicz I
Laboratoire de Biochimie B, Hopital Necker-Enfants-Malades, Paris,
The effects of zinc sulphate and azelaic acid on 5 alpha-reductase
activity in human skin were studied using an in vitro assay with
1,2[3H]-testosterone as substrate. When added at concentrations of 3 or
9 mmol/l, zinc was a potent inhibitor of 5 alpha-reductase activity. At
high concentrations, zinc could completely inhibit the enzyme activity.
Azelaic acid was also a potent inhibitor of 5 alpha-reductase;
inhibition was detectable at concentrations as low as 0.2 mmol/l and was
complete at 3 mmol/l. An additive effect of the two inhibitors was
observed. Vitamin B6 potentiated the inhibitory effect of zinc, but not
of azelaic acid, suggesting that two different mechanisms are involved.
When the three substances were added together at very low concentrations
which had been shown to be ineffective alone, 90% inhibition of 5 alpha-reductase
activity was obtained. If this inhibition is confirmed in vivo, zinc
sulphate combined with azelaic acid could be an effective agent in the
treatment of androgen related pathology of human skin.
PMID: 3207614, UI: 89087983
The reservations one might have regarding the Stamatiadis study are (1)
that the study was done on rats, (2) that is was done on prostate tissue
(and not on hair tissue) and (3) that it was done "in vitro"
(essentially means, "not in a living organism"). Cells in living tissue
generally show a considerable ability to protect themselves from
invasion. Treating pure 5-AR directly with azelaic acid in a lab flask
is somewhat different from exposing the living cell to azelaic acid.
Nevertheless, what happens "in vitro" often reveals clues as to what
might happen "in vivo" (in a living organism).
Side effects: Some of the possible side effects associated with azelaic
acid are white spots or lightening of treated areas of dark skin or
patients with dark complexions, although usually not lightened beyond
normal skin color. Other side effects include burning, stinging, or
tingling of skin, mild, dryness of skin, itching of skin, peeling of
skin, redness of skin. Results from the U.S. clinical trials with AZELEX®
show that adverse reactions were generally mild and temporary in nature.
The most common adverse reactions occurring in approximately 1-5% of
patients were pruritus, burning, stinging and tingling. Other such as
erythema, dryness, rash, peeling, irritation, dermatitis, and contact
dermatitis were reported in less than 1% of test subjects.
Azelaic acid together with topical zinc and B6 (brand name Crinagen) can
be purchased from Dr. Razack.
Topical minoxidil that includes azelaic acid can be purchased from
Dr. Oscar Klein.
acid cream, 20% concentration (brand name Skinoren) can be purchased
with Dr. Klein