Taking medication when you have a cold does not usually delay menstruation. Menstruation is actually influenced by the endocrine axis of the pituitary gland, hypothalamus, uterus and ovaries. It is regulated and fluctuates mainly by estrogen and progesterone, leading to a regular stripping of the uterine lining and menstruation. It is clear from this process that only medications containing estrogen and progesterone affect menstruation, resulting in delayed or early menstruation. Medications that do not contain estrogen and progesterone usually do not cause changes in menstruation; typically antibiotics or cold remedies do not contain estrogen or progesterone and do not affect menstruation. When menstruation is delayed, women of childbearing age must be alert to the possibility of pregnancy. If there are any other discomforts, it is even more important to seek prompt medical attention.