Desmopressin

How it works

Acts like vasopressin on kidney V2 receptors to hold water, yet barely raises blood pressure. Fewer 3 a.m. bathroom runs.

What it's made of

9 amino acids: vasopressin with two changes. The amino group at the start was removed, and the arginine was swapped for its mirror image (D). It lasts longer and barely raises blood pressure.

What it's for

Prescribed for

Central diabetes insipidus, nocturnal enuresis, nocturia from making too much urine at night and, given IV, mild hemophilia A and type 1 von Willebrand disease.