There are no specific homeopathic medicines which are thought to be more effective than others in augmenting a person's own immune and defense system. Each homeopathic medicine is thought to be effective when it is properly prescribed. The trick is to find the correct homeopathic medicine that fits the person's unique pattern of symptoms.
For instance, arsenicum album (white arsenic) is a very common homeopathic medicine. There are numerous acute and chronic conditions for which it is effective in treating, ranging from food poisoning and digestive disorders, to fatigue and various anxiety states, and to asthma and insomnia. Arsenicum album is not effective because it has antibiotic properties or stimulating or sedative effects. It is effective according to basic homeopathic principles because it has the capacity to heal those specific patterns of symptoms it is known to cause if taken in large dose. Arsenicum album will not be effective in treating a person whose symptoms do not match the symptoms that arsenic is known to cause.
There are various books that help people to find the correct single homeopathic medicine. This individualization of medicine is sometimes easy and sometimes hard. If a person does not know how to find the correct remedy or if this medicine is not readily available, it is often useful to use one of the various homeopathic formulas available to the general public.
Although some authors, including myself, have accidently described homeopathic medicines as immunostimulating drugs, it may be more accurate to refer to them as immunomodulating drugs (drugs that stimulate a depressed immune system and that tone down an overactive immune system).
Immunomodulating effects from drugs may be the ideal effect that drug companies and physicians have longed for. Ironically, these drugs have been with us for a long time. Indeed, it is time to further investigate homeopathic medicines.