Estradiol valerate has not been studied during breastfeeding. Injectable estradiol valerate has been used to suppress lactation, usually in combination with testosterone. Generally, it should be avoided in mothers wishing to breastfeed. Oral estradiol valerate is only available in the United States in a combination oral contraceptive product that also contains dienogest. Based on the available evidence, expert opinion holds that nonhormonal methods are preferred during breastfeeding and progestin-only contraceptives are preferred over combined oral contraceptives in breastfeeding women, especially during the first 4 weeks postpartum. For further information, consult the record entitled, "Contraceptives, Oral, Combined."