Herbs Hub
Licorice root, Glycyrrhiza glabra. Botanical plate: Köhler Glycyrrhiza
Plate: Köhler Glycyrrhiza. Unknown authorUnknown author. Public domain.

Licorice root

Glycyrrhiza glabra · 甘草

Herbs & Roots. Ayurveda, Chinese Medicine and Western & European.

Also called Liquorice, Sweet root, Yashtimadhu, Gan cao

Pinyin: Gān Cǎo

Spanish: Regaliz

Sanskrit: यष्टिमधु (Yashtimadhu)

Raises blood pressure, lowers potassium

Licorice root is a sweet root used in Ayurveda, Chinese and Western herbal medicine for sore throat and stomach upset, but high doses can raise blood pressure.

Did you know? Glycyrrhizin, the sweet compound in licorice root, is about 50 times sweeter than table sugar.

What it may help, and how strong the proof is

  • Sore throat & cough. Some small trials show licorice lozenges ease sore throat. Results are mixed, and the trials are small.
    Early proof
  • Digestion & gut health. Small trials of deglycyrrhizinated licorice (DGL) report relief from heartburn and stomach upset. Results are mixed.
    Early proof
  • Inflammation. Lab studies show anti-inflammatory and antiviral effects. Human evidence is thin.
    Traditional proof

Parts of the body

Mouth & throat, Lungs, Gut & intestines, Stomach, Immune system, Joints

Traditional use

Ayurveda calls it yashtimadhu, a rejuvenative that is used for the voice and skin. Chinese medicine calls it gan cao and adds it to many formulas to balance the other herbs.

How it is classified

Herbal actions
Demulcent, Expectorant, Antispasmodic. Energy: cooling.
Ayurveda
Calms Vata and Pitta. Can raise Kapha. Taste (rasa): sweet. Energy (virya): cooling. After digestion (vipaka): sweet. Rasayana (rejuvenative), Varnya (complexion), Kanthya (voice and throat).
Chinese medicine
甘草 Tonify Qi. Nature: neutral. Flavour: sweet. Enters the Heart, Lung, Spleen and Stomach channels.

How people take it

Licorice tea is usually one to two cups a day for short periods. Keep glycyrrhizin intake well under about 100 mg a day, and avoid long-term daily use.

Tea, lozenge and tablet.

Where to get it

Grows wild and is cultivated in southern Europe, the Middle East, and Central and East Asia. Sold as dried root, tea, lozenges, extracts and DGL tablets, and much of the 'licorice' candy sold in the U.S. is flavored with anise instead.

Be careful

High or regular intake can raise blood pressure, lower potassium, and cause fluid retention, swelling, weakness and heart rhythm problems. The risk is higher with age, high blood pressure, kidney disease or heart disease. Avoid it in pregnancy, and use DGL if you want the stomach benefit without the blood pressure risk.

Avoid if: pregnancy; high blood pressure; heart disease; kidney disease; low potassium.

Mixing with other things

  • Works well together

    A common throat blend partner, and licorice also soothes the throat.

  • Works well together

    A common pairing in throat lozenges and soothing teas.

  • Works well together

    Part of Si Jun Zi Tang (Four Gentlemen Decoction), a classic TCM tonic formula.

  • Works well together

    Part of Si Jun Zi Tang (Four Gentlemen Decoction).

  • Works well together

    Part of Si Jun Zi Tang (Four Gentlemen Decoction).

  • Works well together

    Licorice soothes the throat and is often combined with cough herbs.

  • Works well together

    Jujube and licorice (gan cao) are paired in Gan Mai Da Zao Tang (Licorice, Wheat and Jujube Decoction), used in tradition for restlessness and low mood.

  • Works well together

    Bai shao and licorice form Shao Yao Gan Cao Tang (Peony and Licorice Decoction), used for cramps in tradition and in Japanese Kampo.

  • Works well together

    Licorice is also in Ge Gen Tang to balance the formula.

  • Works well together

    Also in Ma Huang Tang, where licorice is added to moderate the formula.

  • Don't mix
    Blood pressure medicine (lisinopril, amlodipine, losartan)

    Raises blood pressure and works against blood pressure medicines.

  • Don't mix
    Heart rhythm medicine (digoxin, amiodarone)

    Low potassium from licorice raises the risk of dangerous heart rhythms with heart medicines such as digoxin.

  • Use caution
    Water pills (furosemide, hydrochlorothiazide)

    Can lower potassium, adding to the effect of water pills.

  • Use caution
    Immune-suppressing medicine (transplant drugs, some arthritis drugs)

    Can add to potassium loss and fluid retention with steroid medicines.

  • Use caution

    Licorice also lowers potassium, so using both adds risk.

Found in these formulas

Four Gentlemen (TCM), Free & Easy Wanderer (TCM), Honeysuckle & Forsythia (TCM), Restore the Spleen (TCM), Sour Jujube Decoction (TCM), Chest & breath tea (Western)

The honest take

Licorice has real but small trial evidence for sore throat and stomach upset. The bigger issue is safety, since regular use of candy, tea or extract can raise blood pressure and lower potassium, sometimes seriously. Choose DGL for stomach use, and limit whole licorice to short periods.