I often tell my patients that Homeopathy is one of the best kept secrets. In acute conditions or emergencies, the correctly prescribed remedy can work within minutes. Acute conditions like colds & flu can clear up within a few hours of taking the medicine, especially if the remedy was started right at the onset.
Other acute conditions like sinusitis, gastro etc can take between 1-3 days to clear, depending on the underlying health status of the individual concerned.
In terms of chronic conditions like infertility and autoimmune disease the period required is more variable. In chronic conditions a degree of improvement can usually be seen within the first month of treatment.
The rule in general is, for every year an individual has had a chronic condition, a month of treatment is required to reverse organic and functional changes that have taken place in the body.