High-dosage norethisterone has been used to suppress menstruation in women with severe intellectual disability who were incapable of handling their own menses. A study of 118 nulliparous women treated with 5 mg/day norethisterone for a period of 2 to 30 months found that the drug was effective in producing amenorrhea in 86% of the women, with breakthrough bleeding occurring in the remaining 14%. Side effects including weight gain, hirsutism, acne, headache, nausea, and vomiting all did not appear to increase in incidence and no "disturbing side effects" were noted in any of the women. Another study of 5 mg/day norethisterone in 132 women also made no mention of androgenic side effects. These findings suggest little to no risk of androgenic side effects with norethisterone at a dosage of 5 mg/day. A study of 194 women treated with 5 to 15 mg/day NETA for a median duration of 13 months of therapy to suppress symptoms of endometriosis observed no side effects in 55.2% of patients, weight gain in 16.1%, acne in 9.9%, mood lability in 8.9%, hot flashes in 8.3%, and voice deepening in two women (1.0%).