Excretion of medicinal substance or its metabolites from the body is carried out by all excretory organs (kidneys, intestines, lungs, dairy, salivary, sweat glands, etc.). The medication effects could be gone even though it is still in your system. Most drugs offered by My Canadian Pharmacy have a half-life of about 24 hours, so they are excreted within 4-5 days. Only several medications have very long half-lives.