Mention the word “licorice,” and most people think of the chewy black candy that they’ve been eating since they were kids. But licorice is also a potent herb that has been used since ancient times for medicinal purposes.
Licorice root, or
glycyrrhiza glabra
, comes from a purple and white flowering perennial that originated in the Mediterranean region and central and southwest Asia. Traditionally, it has been boiled to extract its sweetness, and has been used in making licorice candy. But licorice root, by itself or in compounds with other herbs, has many medicinal uses.
Deglycyrrhizinated Licorice (DGL)
Licorice root contains
glycyrrhizin
, a substance that can cause fluid retention, increased blood pressure, and loss of potassium, when taken in large amounts, or in moderate amounts for two weeks or more. To prevent this effect, some manufacturers remove glycyrrhizin from the licorice root, to produce a licorice-related product called
deglycyrrhizinated licorice, or DGL
.
Gastric Ulcers and Stomach Irritation
–Licorice is believed to have a protective effect on the cells lining the stomach and appears to increase blood flow. A combination therapy containing DGL and ordinary antacids has been used to prevent and treat
peptic ulcers
.
Weak evidence also suggests that DGL might help protect the stomach from the irritation and ulcers caused by nonsteroidal anti-inflammatory drugs.
Licorice in combination with other herbal products is also frequently used for treatment of dyspepsia.
Mouth Sores
–DGL might help relieve the discomfort of
canker sores
in the mouth, although there haven’t been any studies on this subject. The main problem with DGL is that it must be sucked to coat the canker sores, and some people find its taste objectionable.
Eczema, Psoriasis, and Herpes
–A topical licorice cream (often mixed with
chamomile
extract) is sometimes used to treat various skin conditions, such as
eczema
,
psoriasis
, and herpes, but there is no evidence that it is effective.
Sore Throat
–Whole licorice and DGL have been used for soothing a sore throat.
Other Conditions
–Whole licorice has been proposed as a treatment for other conditions including
cancer
,
hepatitis
,
chronic fatigue syndrome
, and
menopausal symptoms
. At this time, however, there is no meaningful evidence that it is effective for these conditions.
For ulcer treatment, the standard dose of DGL is 2-4 380 mg tablets taken before meals and at bedtime. For mouth pain, the tablets can be slowly dissolved in the mouth.
The standard dose of whole licorice is 5-15 grams per day. However, many medical experts do not recommend using doses this high for more than one week. Excessive use of licorice (not DGL) may increase blood pressure, and cause fluid retention, headache, and loss of potassium.
A maximum adult dose of 0.3 grams of licorice root per day has been recommended by experts for long-term use. Larger doses should only be taken under the supervision of your doctor.
Licorice is also available in a liquid form.
Other Side Effects
Note that some licorice candies, as well as “smokeless tobacco” contain substantial amounts of licorice, and can cause licorice side effects.
Whole licorice reduces testosterone in men, and therefore may adversely affect fertility or libido. Licorice use should be avoided by women who are pregnant or nursing, or who have had
breast cancer
.
Drug Interactions
When taken with thiazide diuretic medication, licorice may increase potassium loss. Sensitivity to digitalis glycosides may occur with loss of potassium. Licorice should not be taken with the following medications:
- Cardiac glycosides
- Stimulant laxatives
- Diuretics
- Steroids
- Any potassium-depleting drugs
- Antihypertnesive medications
If you’re considering taking licorice root or DGL, talk to your doctor first to rule out potential drug interactions or other concerns.
