Clomid is definitely an oral drugs that can be used to trigger ovulation. It really works by preventing estrogen receptors at the hypothalamus, and is an important "hormonal control location" for the figure. After this occurs, the hypothalamus is stimulated to launch follicle exciting hormone (FSH), and luteinizing hormone (LH). These tend to be the naturally happening ovarian stimulants, which prompt ovulation in a regular pattern.