Correction - updated December 12, 2018
Some preparations do contain active ingredients in concentrations sufficient to have physiological effects.
Homeopathy has been a form of medicine for hundreds of years. Dana Ullman, whose father was a medical doctor, a pediatrician and allergist, has dedicated a significant portion of his professional life to the practice of homeopathy. Ullman was introduced to this medical art as a junior at University of California (UC) Berkeley, in 1973.
"A Stanford-trained doctor and a male midwife created a group of people to study homeopathy together: three doctors, two nurses, two yoga teachers, a dentist and several laypeople. We met weekly for five years. Towards the end of that, I was honored to be arrested for practicing medicine without a license. That was in 1976.