are many instances in the history of science where great pioneers
and new scientific theories were met with resistance. William Harvey
(nature of blood circulation), Joseph Lister (antiseptic technique)
and Louis Pasteur (germ theory) are notable examples. Today's quacks
boldly claim that they too are scientists ahead of their time. Close
examination, however, will show how unlikely this is.
Galileo, Harvey, Lister, and Pasteur overcame opposition to their
theories by demonstrating the soundness of their ideas with scientific
evidence. They, and other scientists, built up such a large amount
of supporting evidence that their peers just had to accept their
ideas. Sooner or later, all new theories are proven or disproven
by a build up of scientific evidence for or against them. Many theories
of treatment for hair loss supported by snake oil sellers either
have no supporting scientific evidence or there is evidence that
directly refutes the theory.
There are many more instances in scientific history where new scientific
theories were proved flawed or just plain wrong. The Federal Drug
Administration (FDA) of the USA has investigated around 250,000
claims for products that regrow hair. All but three (minoxidil 2%,
minoxidil 5%, Propecia) have been rejected as worthless.