A method for selecting a treatment for a subject suffering from androgenetic alopecia, comprising: (i) performing an assay to measure minoxidil sulfotransferase activity in a sample of one or more hair follicles or of a scalp biopsy of the subject, thereby generating an activity value indicative of the minoxidil sulfotransferase activity level in the sample; wherein the assay comprises the steps of: (a) placing the one or more hair follicles or the scalp biopsy in a reaction mixture containing about 50 mM potassium phosphate buffer with pH between about 6.5 and about 8.0, about 5 mM magnesium chloride, about 20 μM adenosine 3',5'-diphosphate or adenosine 3'-phosphate,5'-phosphosulfate (PAPS), about 5 mM p-nitrophenyl sulfate and about 0.1 mM minoxidil; (b) mixing the reaction mixture; (c) incubating the reaction mixture for a predetermined length; and (d) stopping the reaction (ii) comparing the activity value to one or more standardized activity values, each standardized activity value representing either high or low expected minoxidil response for hair re-growth or retention for a class of patients including the subject, thereby producing an indication of either high or low expected minoxidil response for hair re-growth or retention for the subject at a particular dosage of minoxidil, wherein the one or more standardized values are one or more minoxidil sulfotransferase activity levels at which a statistical sample of other subjects show either high or low minoxidil response for hair re-growth or retention at the particular dosage of minoxidil; and (iii) presenting the indication to the subject. (i) performing an assay to measure minoxidil sulfotransferase activity in a sample of one or more hair follicles or of a scalp biopsy of the subject, thereby generating an activity value indicative of the minoxidil sulfotransferase activity level in the sample; wherein the assay comprises the steps of: (a) placing the one or more hair follicles or the scalp biopsy in a reaction mixture containing about 50 mM potassium phosphate buffer with pH between about 6.5 and about 8.0, about 5 mM magnesium chloride, about 20 μM adenosine 3',5'-diphosphate or adenosine 3'-phosphate,5'-phosphosulfate (PAPS), about 5 mM p-nitrophenyl sulfate and about 0.1 mM minoxidil; (b) mixing the reaction mixture; (c) incubating the reaction mixture for a predetermined length; and (d) stopping the reaction (a) placing the one or more hair follicles or the scalp biopsy in a reaction mixture containing about 50 mM potassium phosphate buffer with pH between about 6.5 and about 8.0, about 5 mM magnesium chloride, about 20 μM adenosine 3',5'-diphosphate or adenosine 3'-phosphate,5'-phosphosulfate (PAPS), about 5 mM p-nitrophenyl sulfate and about 0.1 mM minoxidil; (b) mixing the reaction mixture; (c) incubating the reaction mixture for a predetermined length; and (d) stopping the reaction (ii) comparing the activity value to one or more standardized activity values, each standardized activity value representing either high or low expected minoxidil response for hair re-growth or retention for a class of patients including the subject, thereby producing an indication of either high or low expected minoxidil response for hair re-growth or retention for the subject at a particular dosage of minoxidil, wherein the one or more standardized values are one or more minoxidil sulfotransferase activity levels at which a statistical sample of other subjects show either high or low minoxidil response for hair re-growth or retention at the particular dosage of minoxidil; and (iii) presenting the indication to the subject.