Licorice is used for stomach and duodenal ulcers, sore throat,
bronchitis, gastritis, indigestion, colic, insufficiency of the
adrenal cortex and cough. In combination with Panax ginseng and
Bupleurum falcatum, licorice is used orally to help stimulate
adrenal gland function, particularly in patients with a history
of long-term corticosteroid use. As a component of the herbal
formula, Shakuyaku-Kanzo-To, licorice is used to increase
fertility in women with polycystic ovary syndrome. In combination
with other herbs, licorice is used to treat prostate cancer and
No concerns regarding safety when used orally in amounts commonly
found in foods.
Possibly Safe when used orally and appropriately for medicinal
purposes in the short-term.23,24,25,26,29,32
Long-term use increases the risk of side effects such as
hypertension and low potassium33 in susceptible
Pregnancy and Lactation: Refer to a Medical Herbalist.
Dyspepsia. A specific combination product containing licorice
(Iberogast, Medical Futures, Inc) seems to improve symptoms of
dyspepsia. The combination includes licorice plus peppermint
leaf, German chamomile, caraway, lemon balm, clown's mustard
plant, celandine, angelica, and milk thistle.30,27 A
meta-analysis of studies using this combination product suggests
that taking 140 mL orally three times daily over a period of
4-weeks significantly reduces severity of acid reflux, stomach
pain, cramping, nausea, and vomiting compared to
INSUFFICIENT SCIENTIFIC EVIDENCE to VERIFY:
Muscle cramps. Preliminary clinical research suggests taking a
specific combination of licorice and peony may reduce muscle
cramps in patients with hepatic cirrhosis or in patients
Peptic ulcers. There is some evidence that deglycyrrhizinated
licorice might accelerate the healing of peptic
Weight loss. There is conflicting information about the use of
licorice for weight loss. Licorice has been shown to reduce body
fat, however accompanying fluid retention offsets any change in
More evidence is needed to rate licorice for these uses.
Mechanism of Action:
The applicable part of licorice is the root. Licorice has
antispasmodic, anti-inflammatory, laxative, and soothing
Licorice appears to block metabolism of prostaglandins linked to
inflammation, which suggests the possible beneficial effect on
Cortisol promotes sodium and water retention and potassium
ingestion can therefore produce a syndrome of apparent
excess of adrenal cortical hormones leading to increased urinary
potassium loss and
There is considerable variation in the amount of licorice needed
to cause these effects, due in part to variation in the
glycyrrhizic acid content of licorice preparations. There is also
variation in people's response to licorice. Those with
hypertension, heart disease, kidney disease, or a high salt
intake are more sensitive to its effects.47,37,40,41
Finally, case reports of adverse reactions to licorice do not
always make it clear whether licorice intake is in grams of pure
licorice, or grams of sweet licorice candy or salty licorice or
The increases in blood pressure, and cortisol to cortisone ratio
are proportional to the amount of glycyrrhizic
Licorice appears to have anti-estrogenic and estrogenic action.
Preliminary research indicates that licorice does not stimulate
the growth of estrogen dependent breast cancer
cells.48 However, the estrogenic effects of licorice
might be concentration dependent. Glabridin, an isoflavone
constituent of licorice, seems to have an estrogen
receptor-dependent growth-promoting effect at low concentrations.
At higher concentrations, it seems to have an
estrogen receptor-independent antiproliferative
Orally. excessive licorice ingestion can cause a
problem with overproduction of adrenal cortex
hormones.42,28,43,44,37,38,45,46,39,40,41,52,53These effects are most likely to occur when 30 grams or
more of licorice is consumed daily for several
Interactions with Herbs & Supplements:
Cardiac Glycoside-Containing Herbs: None commonly found in
products in Ireland.
Stimulant Lasative Herbs: Excessive amounts can be an
Interactions with Drugs:
Antihypertensive Drugs: Refer to Medical Herbalist
Corticosteroids: Refer to Medical Herbalist
Digoxin: Refer to Medical Herbalist
Diuretic Drugs: Refer to Medical Herbalist.
Estrogens: Avoid high dosages and prolonged treatment.R1
Interactions with Foods:
Grapefruit Juice: Theoretically, grapefruit juice and its
component naringenin might enhance the mineralocorticoid
activities of licorice, by blocking the conversion of cortisol to
Salt: A high salt diet can exacerbate adverse effects of licorice
such as sodium and water retention and hypertension.41
Interactions with Lab Tests:
1407-Hydroxyprogesterone: Licorice can increase serum
1407-hydroxyprogesterone concentrations and test results in
healthy volunteers who consume 7 grams of licorice per
Potassium: Excessive use of licorice can affect
Interactions with Diseases or Conditions:
Heart Disease: Refer to a Medical Herbalist.
Hormone Sensitive Cancers/Conditions: As above.
Hypertension: Advise patients with hypertension to avoid
excessive amounts of licorice.58,59
Kidney Insufficiency: Advise patients with severe renal
insufficiency to avoid excessive amounts of
Surgery: discontinue licorice 2 weeks before elective surgical
Dr Clare’s Blends: has a recommended dose of 5mls per week i.e
140.4mls per day of 140:3 extract = ½ gram daily.
Oral: For dyspepsia, a specific combination product containing
licorice (Iberogast, Medical Futures, Inc) and several other
herbs has been used in a dose of 140 mL three times
2-6ml/day of 140:140 extract
6-1402ml/day of 140:3 extract
Dried Root 140-4gms per day.
Dr Clare’s Comment:
The effect of liquorice on the Adrenal Glands is beneficial for
most patients, however a small group of patients are sensitive to
the effects on blood pressure. Under normal circumstances this
would not be significant for short term low dose use. It can be
monitored by taking blood pressure and many chemists have a blood
pressure machine patients can check during treatment if you do
not have resources to check the blood pressure.
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