Lot of discussion has taken place over past two decades about what homeopathic medicines contain at what level of potentization and how do they work. This is where homeopathy philosophy and procedure to dynamized the medicines come in. Unless this is clearly understood with open mind, any answer would be debatable.
Homeopathic medicines are not to be viewed like other medicines that contain measurable quantity of the drug. The starting medicine that is Mother Tincture or Mother Triturate does contain measurable physical substance but as it is diluted (or potentized as we call it), the drug content reduces with every next potency till it disappears around 24X. Beyond that, homeopathic medicines do not contain measurable drug substance in physical form but they become more effective due to the process of dynamization. This is where the critique starts on the plea that if homeopathic potencies do not contain measurable drug substance, how do they work. Those who understand the working of various types of energies would understand that homeopathic potencies work on energy level, not on material level. With every higher potency, the amplitude of the energy rises making it even stronger and more effective.
Take the example of water prepared/energized according to the philosophy of chromotherapy that contains no material drug substance at all, not even to start with but it works. Similar is the case with homeopathic medicines. They work excellently in potentized form even though they do not contain measurable drug substance. This is the reason why sometimes homeopathic medicines in potentized form are also called energy medicines.