Fludrocortisone, sold under the brand name Florinef among others, is a [[corticosteroid]] which is used to treat adrenogenital syndrome, postural hypotension, and adrenal insufficiency.

In adrenal insufficiency it is generally taken together with [[hydrocortisone]]. It is taken by mouth. The medication is most commonly used in its acetate form.

Common side effects include high blood pressure, swelling, heart failure, and low blood potassium. 

Other serious side effects include low immune system function, cataracts, muscle weakness, and mood changes. It is unclear if use during pregnancy is safe for the baby.

Fludrocortisone is mostly a mineralocorticoid; however, also has glucocorticoid effects.

Fludrocortisone was patented in 1953.

It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.  In the United Kingdom it costs the NHS about 1.52 pounds per month. In the United States the wholesale cost of a month of medications is about 11.96 USD.