This is prescription powder and it has helped me with both Candida and Toenail Fungus. It is very cheap in powder form and a jar last for a very long time. Shirley Nystatin USP is an anti-yeast anti-fungal compound derived from Streptomyces noursei and is a close relative of amphotericin-8 2 It is a polyene antibiotic which increases the permeability of cell membranes in yeast and is considered fungistatic and fungicidal. Taken orally, it will have an effect on the gastrointestinal yeast throughout the entire alimentary tract, but has no significant systemic absorption. Although poorly absorbed, persons with renal insufficiency may develop high plasma concentrations. Nystatin is commonly used to treat oral and anal thrush (moniliasis) in children and is also used in vaginal candidiasis. The dosage is 500,000 units four times daily. As a powder, this is 1/8 teaspoon in an ounce or two of water; as a tablet, this is one tablet each dose; and as the suspension, this is one teaspoon per dose. It comes in many forms, including oral suspension (mixed in 50% sucrose to deaden its bitterness), oral tablets, powder, creams or ointments, and vaginal tablets. We chose the powdered form because it is theoretically more effective through the entire GI tract than the tablets which affect the lower GI tract only. The syrup is 50% sucrose, and it would appear to be contraindicated in treatment of the very yeast that feed on sugars. One patient in the current trial who was reasonably well-controlled on oral powder switched to the suspension for logistical reasons. She typically would become aware of response to the Nystatin within 3 to 4 days whenever starting or stopping the powder, but became worse whenever she substituted the suspension. There are no known long-term side effects or serious known complications with the drug. A few people have complained of nausea or headache. These symptoms are usually eliminated by reducing the amount of Nystatin taken until better tolerance is achieved.