snake oil sellers like to include testimonial evidence from users
of their product to "prove" how effective it is in promoting
hair regrowth. However, there are many problems with this kind of
The testimonials included on a web site are selected by the web
site owner who is usually the product seller. Obviously, someone
wanting to sell a product is not going to post testimonials that
tell you the product failed to work. Only the testimonials that
show the product in the best light are going to be published.
We all like to believe what others tell us about personal experiences,
but separating cause and effect from coincidence can be very difficult.
When looking at web sites consider that the people making the testimonials
may not actually have had the condition. Even if they did, their
recovery may have occurred without the help of the product. Many
forms of hair loss, including androgenetic alopecia, are not steadily
progressive. They develop in fits and starts. You may even have
some partial spontaneous recovery, only to lose it again at a later
of us have more hair loss in autumn and early winter and least hair
shedding in spring and early summer. This is because our bodies
are subject to the seasons, yes even despite our artificial light
and central heated world our bodies still feel the need to change
our summer hair "coats" for winter ones.
Other forms of hair loss, such as telogen effluvium, are temporary
and do eventually end with just the passage of time. Establishing
medical truths requires careful and repeated investigation. With
well designed experiments, not reports of coincidences misperceived
as cause and effect. That is why testimonial evidence is forbidden
in scientific articles, is usually inadmissible in court, and it
is not used to evaluate whether or not drugs should be legally marketable.
It would be inappropriate and potentially dangerous if government
health agencies approved drugs based on testimonial letters or interviews
with a few patients.
Finally, some snake oil sellers may simply make up the testimonial
evidence for their product.