The effect upon tryptophan metabolism of the use of combined oestrogen-progestagen oral contraceptives containing a low (0.05 mg) dose of oestrogen, or of the continuous administration of megestrol acetate, has been studied by determining the excretion of tryptophan metabolites in urine collected after a 2 g oral dose of the amino acid. An investigation of 10 women before being given oral contr...
