Minoxidil, the generic name for Rogaine, is a medication that was originally used for treating hypertension because of its ability to dilate blood vessels. One of minoxidil's side effects is preventing hair loss and promoting hair regrowth with female pattern hair loss. Rogaine became the first FDA approved medication for the treatment of hair loss despite the fact that how it works is still unknown. Rogaine is available without a doctor's prescription.
Only the 2 percent formulation of Rogaine has been approved for use in women, according to the Bernstein Medical Center for Hair Restoration. Females tend to be more sensitive to the effects of Rogaine on blood pressure. Minoxidil decreases blood pressure and can cause lightheadedness. Using the 5 percent solution, which is approved for use in men, can increase the severity of side effects.
Women have an increased risk of developing an allergic skin reaction to minoxidil. Contact dermatitis is a delayed allergic reaction characterized by inflammation of the skin, a localized rash and irritation. In the majority of cases, propylene glycol is to blame for the side effect rather than the minoxidil itself, reports the Journal of the American Academy of Dermatology.
In 2004, the Journal of the American Academy of Dermatology studied the effects of 5 percent topical minoxidil versus the 2 percent solution on 381 women. After 48 weeks, an increased occurrence of severe itching, local irritation and excessive body hair growth was observed in women taking the 5 percent formulation.
Pregnancy and Breastfeeding
The FDA places Rogaine in category C on the pregnancy chart, which rates drug safety for pregnant women and fetuses. Category C indicates that a risk of the drug having an effect on an unborn child cannot be ruled out, but there is not enough conclusive evidence regarding whether the drug will have an effect on the fetus. Lactating mothers should not take Rogaine because of the minimal threat it may pose to the infant through minoxidil absorption into breast milk.