Side Effects for Licorice

Licorice root is used in herbal remedies for a variety of reasons, including liver purification, adrenal support and ulcer treatment. Unfortunately, the benefits of using licorice root can come with unwanted side effects. Glycyrrhizin, the compound in licorice thought to provide many of its beneficial properties, is also the compound thought to cause most of these side effects. While licorice candy often contains actual licorice root, it would take one-quarter pound or more of this candy to cause most side effects. Side effects primarily come from supplements in capsule, tincture and tea form, which contain larger amounts of licorice per serving than does candy.

Mineral Imbalance

Licorice root affects both cortisol and aldosterone, which are hormones that influence sodium and potassium levels in the body. When these levels are altered through consumption of licorice root, side effects such as water retention, high blood pressure and headaches can occur. Potassium levels can also become dangerously low, so those taking licorice root should consume potassium-rich foods such as bananas and sweet potatoes. These side effects typically occur after two to three weeks of use with amounts such as 10 g of root, but caution should always be used as side effects can occur even with smaller doses.

Hormone Imbalance

Licorice root alters the levels of testosterone and estrogen in the body. It can increase the amount of testosterone that is changed into estrogen, thereby increasing estrogen levels and lowering testosterone levels. Licorice root, therefore, should not be taken by those with ovarian and breast cancers or by pregnant women. Men suffering from infertility or erectile dysfunction should also avoid licorice root because of its testosterone-lowering effects. According to the University of Michigan Health System, in one study, "Consumption of 7 grams of licorice (containing 500 mg glycyrrhizin) per day for seven days has been shown to decrease serum testosterone levels in healthy men by blocking the enzymes needed to synthesize testosterone."

Drug Interactions

Because licorice root affects potassium levels, it should not be taken with either diuretics or laxatives, both of which can increase the excretion of potassium, increasing the risk of low potassium levels. Licorice root can also increase the effects of insulin, corticosteroids, blood thinners and MAO inhibitors, so people on these medications should avoid it. Anyone on hormone therapy or birth control pills should also avoid licorice because of its effects on estrogen levels.