Nizoral AD Shampoo Treatment
Doctors have known for a long time that
Nizoral shampoo, in prescription and
non-prescription strength, works well for
controlling dandruff. But at last yearīs
meeting of the American Academy of
Dermatology, a group of scientists suggested
that over-the-counter Nizoral might also be
useful as a hair loss remedy. The researchers
compared Nizoral A-D Shampoo, containing 1%
ketoconazole (the active ingredient), to
another shampoo containing 1% zinc pyrithione.
Zinc pyrithione is the active ingredient in
dandruff shampoos such as Head & Shoulders.
They found that Nizoral increased hair
thickness and decreased hair shedding, whereas
the zinc pyrithione shampoo had the opposite
Their presentation didnīt make a big splash
then, and it has faded into obscurity since.
Thatīs probably because what they presented
were the results of a preliminary study--the
results have not yet been duplicated in other
studies by other researchers--and perhaps
because the scientists who did the research
were under the employ of McNeil
pharmaceuticals, the company that makes
Still, itīs not all flimflam. The study met
the basic standards of good research: It was a
randomized, double-blinded study. That means
the researchers used a random process to
decide who would use Nizoral and who would use
the zinc pyrithione shampoo.
Also, the study participants didnīt know which
shampoo they were using, and neither did the
researchers, until the results were in. Both
of these measures are important in conducting
a scientific study because they help eliminate
any bias the researcher s or the study
participants may have, which could skew the
Here is how the study was done:
Forty-four men with "mild to moderate dandruff
and somewhat oily scalp" used Nizoral A-D
Shampoo two or three times a week for six
months, and 43 men with the same scalp
problems used a dandruff shampoo containing
zinc pyrithione just as frequently over the
same period of time. Both shampoos had the
same percentage (1%) of the active ingredient
At the beginning of the study, the researchers
looked at the health of the menīs hair and
scalp. They counted the number of hairs
growing on the scalp. They also measured the
diameter of the hairs, and how many hairs fell
out over a 24-hour period. They took these
measurements again one month into the study,
then again at three months, and one last time
at six months.
The researchers found that the men using
Nizoral had about an 8% increase in the
thickness of their hair. The men using the
zinc pyrithione shampoo had no such increase.
In fact, their hair decreased in thickness by
about 2%. The men who used Nizoral also shed
fewer hairs over a 24-hour period than the
zinc pyrithione shampoo users did. The Nizoral
users shed about 16% fewer hairs, whereas the
zinc pyrithione users shed about 6% fewer
The Nizoral users, however, had fewer hairs
growing on the scalp at the end of six months
than the zinc pyrithione users did. That means
fewer of their hair follicles were in "anagen
Not all the hair on your head grows at once.
At any given time, some hair follicles are
dormant, while others are actively pushing out
hair: Theyīre in the anagen phase, which lasts
about two to six years. After a short
transitional phase, the dormant phase, or "telogen"
phase begins, lasting about five to six weeks.
When a follicle goes back into anagen phase,
the hair that had been growing from it falls
out, and a new hair begins to grow.
In the study, both the Nizoral users and the
zinc pyrithione users had an increase in the
number of hairs in anagen phase. The Nizoral
group had about 6% more, whereas the zinc
pyrithione had about 8% more.
These results may seem to prove that Nizoral
A-D works against hair loss, but they really
donīt: They merely suggest it. Scientists
might be able to get a better idea of how well
Nizoral works as a hair-loss remedy if they
were to do a placebo-controlled study. That
means one group of people would use Nizoral
A-D, while another group would use a shampoo
that contains no medicine at all.
One 1998 study showed that
prescription-strength Nizoral, which contains
2% ketoconazole, worked just as well as
minoxidil (brand name Rogaine) in men with
androgenic alopecia (male hereditary balding).
Both medicines increased hair thickness and
increased the number of anagen-phase hair
follicles on the scalp. But the researchers
were guarded about the meaning of these
results, saying that more rigorous studies on
larger groups of men should be done.
The most certain results come from
placebo-controlled studies done in more than
one place, on groups of people that fit a
wider profile (not just men with dandruff, in
the case of the Nizoral A-D study). This is
whatīs known as the "gold standard" for
medical research--in scientific terms, a
placebo-controlled, multicenter study. This is
the kind of study that the US Food and Drug
Administration wants to see before it will
approve a medicine for a particular use.