Overview

Licorice is an herb that grows in parts of Europe and Asia. Licorice root contains glycyrrhizin, which can cause side effects when eaten in large amounts.

The chemicals in licorice are thought to decrease swelling, decrease cough, and increase the chemicals in our body that heal ulcers. Many "licorice" products made in the U.S. actually don't contain licorice. They contain anise oil, which has the smell and taste of "black licorice".

Licorice is used for eczema, swelling of the liver, mouth sores, and many other conditions, but there is no good scientific evidence to support most of these uses. There is also no good evidence to support using licorice for COVID-19.

Uses & Effectiveness ?

Possibly Effective for

  • Eczema (atopic dermatitis). Applying a gel containing licorice three times daily for 2 weeks seems to reduce redness, swelling, and itching from eczema.
  • Canker sores. Applying a patch containing licorice and using licorice mouth rinses seem to help reduce pain and speed up healing of canker sores.
  • Side effects in people after breathing tube removal. Sucking on a licorice lozenge or gargling with a licorice fluid shortly before placement of a breathing tube seems to help prevent cough and sore throat from occurring when the tube is removed.
There is interest in using licorice for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Licorice is likely safe for most people when eaten in typical food amounts. Licorice that has had the chemical glycyrrhizin removed is possibly safe when taken in doses up to 4.5 grams daily for up to 4 months.

Licorice that contains glycyrrhizin is possibly unsafe when consumed in large amounts or for a long time. Eating licorice 5 grams or more daily for several weeks can cause severe side effects including heart attack. People who have heart disease, kidney disease, or high blood pressure are more sensitive to it. Ingesting large amounts of licorice from candy, lozenges, or tea might also cause serious side effects.

When applied to the skin: Applying gel with licorice root extract 2% is possibly safe for up to 2 weeks. It is possibly safe to use a licorice mouth rinse for up to one week.

Special Precautions and Warnings

When taken by mouth: Licorice is likely safe for most people when eaten in typical food amounts. Licorice that has had the chemical glycyrrhizin removed is possibly safe when taken in doses up to 4.5 grams daily for up to 4 months.

Licorice that contains glycyrrhizin is possibly unsafe when consumed in large amounts or for a long time. Eating licorice 5 grams or more daily for several weeks can cause severe side effects including heart attack. People who have heart disease, kidney disease, or high blood pressure are more sensitive to it. Ingesting large amounts of licorice from candy, lozenges, or tea might also cause serious side effects.

When applied to the skin: Applying gel with licorice root extract 2% is possibly safe for up to 2 weeks. It is possibly safe to use a licorice mouth rinse for up to one week.
Pregnancy: It is unsafe to take licorice when pregnant. It might cause a miscarriage or early delivery. Eating about 250 grams of licorice per week seems to increase the risk of early delivery.

Breast-feeding: There isn't enough reliable information available about the safety of taking licorice when breast-feeding. Stay on the safe side and avoid use.

Heart conditions: Licorice can cause the body to store water, and this can make heart failure worse. Licorice can also increase the risk of irregular heartbeat. Don't consume licorice if you have a heart condition.

Hormone-sensitive conditions such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Licorice might act like estrogen in the body. If you have any condition that might be made worse by exposure to estrogen, don't use licorice.

High blood pressure: Licorice can raise blood pressure. Don't consume large amounts of licorice if you have high blood pressure.

A muscle condition caused by nerve problems (hypertonia): Licorice can lower potassium levels in the blood. This can make hypertonia worse. Avoid licorice if you have hypertonia.

Low potassium levels in the blood (hypokalemia): Licorice can lower potassium levels in the blood. If your potassium is already low, licorice might make it too low. Don't use licorice if you have this condition.

Kidney disease: Consuming large amounts of licorice could make kidney disease worse.

Sexual problems: Consuming large amounts of licorice can lower interest in sex. It can also worsen erectile dysfunction (ED) by lowering levels of testosterone.

Surgery: Licorice might interfere with blood pressure control during and after surgery. Stop taking licorice at least 2 weeks before a scheduled surgery.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Digoxin (Lanoxin) interacts with LICORICE

    Large amounts of licorice can decrease potassium levels in the body. Low potassium levels can increase the side effects of digoxin.

  • Estrogens interacts with LICORICE

    Licorice seems to change hormone levels in the body. Taking licorice along with estrogen might decrease the effects of estrogen.

  • Water pills (Loop diuretics) interacts with LICORICE

    Licorice can decrease potassium levels. Loop diuretics can also decrease potassium levels. Taking licorice and loop diuretics together might make potassium levels drop too low.

  • Medications changed by the liver (Cytochrome P450 2B6 (CYP2B6) substrates) interacts with LICORICE

    Some medications are changed and broken down by the liver. Licorice might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates) interacts with LICORICE

    Some medications are changed and broken down by the liver. Licorice might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates) interacts with LICORICE

    Some medications are changed and broken down by the liver. Licorice might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications for high blood pressure (Antihypertensive drugs) interacts with LICORICE

    Licorice might increase blood pressure. Taking licorice might reduce the effects of blood pressure medications. Monitor your blood pressure closely.

  • Medications for inflammation (Corticosteroids) interacts with LICORICE

    Licorice can decrease how quickly the body breaks down corticosteroids. This can increase the effects and side effects of corticosteroids.

  • Warfarin (Coumadin) interacts with LICORICE

    Warfarin is used to slow blood clotting. Licorice might decrease the effects of warfarin. Decreasing the effects of warfarin might increase the risk of clotting. Be sure to have your blood checked regularly. The dose of your warfarin might need to be changed.

  • Water pills (Diuretic drugs) interacts with LICORICE

    Licorice can decrease potassium levels. "Water pills" can also decrease potassium levels. Taking licorice along with "water pills" might make potassium levels drop too low.

  • Cisplatin (Platinol-AQ) interacts with LICORICE

    Cisplatin is used to treat cancer. Licorice might decrease how well cisplatin works.

  • Midazolam (Versed) interacts with LICORICE

    Licorice might increase how quickly midazolam is broken down by the body. This might decrease the effects of midazolam.

  • Medications changed by the liver (Cytochrome P450 2C19 (CYP2C19) substrates) interacts with LICORICE

    Some medications are changed and broken down by the liver. Licorice might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 2C8 (CYP2C8) substrates) interacts with LICORICE

    Some medications are changed and broken down by the liver. Licorice might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Paclitaxel (Abraxane, Onxol) interacts with LICORICE

    Licorice might increase how quickly the body breaks down paclitaxel. Taking licorice with paclitaxel might decrease the effects of paclitaxel.

  • Medications moved by pumps in cells (P-glycoprotein substrates) interacts with LICORICE

    Some medications are moved in and out of cells by pumps. Licorice might change how these pumps work and change how much medication stays in the body. In some cases, this might change the effects and side effects of a medication.

    Minor Interaction

    Be watchful with this combination

  • Methotrexate (Trexall, others) interacts with LICORICE

    Licorice might decrease how quickly the body breaks down methotrexate. This might increase the effects and side effects of methotrexate.

Dosing

Licorice is available in many different types of products, including candies, lozenges, teas, chewing tobacco, creams, gels, patches, sprays, mouth washes, and others. Licorice extract has most often been used by adults in doses of 100-990 mg by mouth daily for 2-24 weeks.

Licorice naturally contains a chemical called glycyrrhizin. The amount of glycyrrhizin usually ranges from 1% to 12%. Most of the side effects from licorice are caused by this chemical. Licorice products that have had glycyrrhizin removed are sometimes called deglycyrrhizinated licorice (DGL).

Many "licorice" products manufactured in the U.S. actually don't contain any licorice. Instead, they contain anise oil, which has the smell and taste of "black licorice".

View References

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2020.