Latuda can increase prolactin levels, especially at dosages more than or equal to 120 mg/day. One study reported 5.7% of female patients and 1.6% of males with prolactin levels at least five times the upper limit of normal, compared with 2% of placebo-treated females and 0.6% for placebo-treated males.

Prolactin is a hormone made by the pituitary gland that can interfere with the normal production of other hormones, such as estrogen and progesterone. Hyperprolactinemia (high levels of prolactin) can change or stop ovulation (the release of an egg from the ovary), cause irregular or missed periods, infertility, and menopausal symptoms (hot flashes and vaginal dryness) in women. In both males and females symptoms can include loss of sex drive, galactorrhea (breast milk production), and, after several years, osteoporosis (thinning and weakening of the bones).