Pregnancy: Zenavil is not indicated for use by women. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/foetal development, parturition or postnatal development (see Pharmacology: Toxicology: Preclinical safety data under Actions).
Fertility: Effects were seen in dogs that might indicate impairment of fertility. Two subsequent clinical studies suggest that this effect is unlikely in humans, although a decrease in sperm concentration was seen in some men (see Pharmacology: Pharmacodynamics and Pharmacology: Toxicology: Preclinical safety data under Actions).