Licorice: A Cautionary Tale of Glycyrrhizin and its Aglycones
From Keli: Hi, my question is about licorice root. I make a tea, that contains licorice root along with Turmeric, ginger, lemon verbena, black pepper, and lemon peel. Once I mix all together, there is about 1/4 tsp of licorice root per 6oz cup being used. My question is, is this a safe amount of licorice root in my tea, if I am not pregnant, nor do I have high blood pressure? The info I have seen about it says that you shouldn't take licorice tea for longer than 5-6 weeks. If I am drinking this 2-3 times a week, am I at risk of depleting my potassium? Thanks so much for your help, it is appreciated.
Recommendations for licorice root often carry words of caution due to its known mineralocorticoid-like action — in high doses individuals may experience increased extracellular fluid and plasma volume, sodium retention and loss of potassium which leads to hypertension. While that sounds scary (and it is), let's dial this back a bit then work up to the phytochemistry linked to this warning.
I am be referencing several text books that are listed below.
The common name for licorice is sweetroot and it is a member of the pea family, Fabaceae or Leguminosae. There are 14 licorice species, 10 of which are known to have a sweet root. The most commonly used species in herbal medicine is Glycyrrhiza glabra.
Herbal properties include: bitter, expectorant, laxative, anti-inflammatory, antispasmodic, demulcent, anti-ulcer.
Systems Affected: glandular, digestive and respiratory.
Licorice root has long been revered as a sweetener and a medicinal plant throughout the world. The herb was used by ancient Greeks, Romans, Babylonians, Egyptians and Hindus. It is the most often used herb in TCM (Traditional Chinese Medicine) formulas, serving as a harmonizer or as a primary component. Numerous herbalists have cited the merits of the plant including ancient texts of Divine Husbandsman's Classics, Hippocrates, Pliny and (slightly more contemporarily) by Culpepper and Mrs. Grieves. Into today, it continues to be a widely used herb with many clinical trials. Licorice is listed among the 'Monographs on Adaptogens' in David Winston & Steven Maimes 2007 book, Adaptogens, Herbs for Strength, Stamina, and Stress Relief.
The nutritional profile and phytochemical composition is the basis of your question. Nutritionally, licorice is very high in magnesium, silicone and sodium. Phytochemically, the saponin-like compound, glycyrrhizin is 50 times sweeter than sugar. This saponin-like quality helps the absorption of otherwise poorly absorbed substances (food or drugs). The glycyrrhizin and its aglycones, including glycyrrhizic acid, are responsible for the sodium retention and loss of potassium.
The other properties of licorice can be attributed to its flavonoids and coumarin derivatives. These substances produce the antispasmodic, anti-ulcer and antimicrobial effects of the herb.
The following safety recommendations are provided for therapeutic dosing of licorice root as a tea:
Commission E (EU): 5 to 15 grams per day, equivalent to 200 to 600 mg glycyrrhizin consumed daily for 4 to 6 weeks. The acceptable daily dosage of glycyrrhizin as a sweetener is 100 mg.
Botanical Safety Handbook (AHPA, US): 1 to 5 grams 3 times daily for up to 6 weeks.
The amount of total triterpenoids and glycosides (including glycyrrhizin) in the licorice root is between 7 to 15%. Based on the ratio provided in the Commission E where 5 g = 200 mg of glycyrrhizin, that correlates to an estimate of 4%.
So how much glycyrrhizin is in your 1/4 teaspoon of ground licorice?
I did not have ground licorice on hand, but I do have slices and many of us are familiar with this form of the herb. The size and thickness of the pieces varies quite a bit. To estimate the gram weight of the average slice of licorice root, I performed a little experiment. Today I weighed 4 separate samplings of 10 slices of licorice root each. The total weight of the 10 pieces were: 3.95, 5.18, 6.14 and 6.6 grams, respectively. If we average the gram weight results, we get an average of 5.45 grams for 10 slices of licorice root; that would make the average slice 0.545 gram.
Therapeutic dosing of 5 to 15 grams would be 10 to 30 slices a day for up to 4-6 weeks.
After all that, I figure, your 1/4 teaspoon may be 1 to 2 slices worth of root. So, estimate 1 gram (1000 mg) then 4% would be 40 mg glycyrrhizin, consumed 2-3 times a week. Your rate of consumption is within the acceptable range as a sweetener. In fact, the licorice in your tea may be facilitating the absorption of the other herbs in your tea or acting as an 'ambassador'.
The shorter answer is: no you are not near the dosage associated with potassium depletion.
I hope this helps.
Pedersen, M, Nutritional Herbology, 2008
editors: McGuffin, Hobbs, Upton, Goldberg, The American Herb Products Association, Botanical Safety Handbook, 1st edition, 1997
editors, Blumenthal, Busse, Goldberg, Gruenwald, Hall, Klein, Riggins & Rister, The Complete German Commission E Monographs, Therapeutic Guide ot Herbal Medicines, 1st edition, 1998
Bensky & Gamble, Chinese Herbal Medicine Materia Medica, 2nd edition, 1998
Judith Fox Smith, MS, is the founder of Foxsmyth Herbal, in Stoneham, MA. Judy is a biological research scientist and clinical herbalist. She is the founder and past president of the Eastern PA chapter of American Herbalist Guild, the Herb Gatherers of Lansdale, PA and past Vice President of San Antonio Herb Society. She combines her knowledge of biology and botany with her passion to provide practical herbal and lifestyle recommendations for a holistic balance in today’s techno-driven world.