Exit

Nutritional Supplement

Licorice

Side Effects

Licorice products that include glycyrrhizin may increase blood pressure and cause water retention and potassium deficiency.46 Some people are more sensitive to this effect than others. Long-term intake (more than two to three weeks) of products containing more than 1 gram of glycyrrhizin (the amount in approximately 10 grams of root) daily is the usual amount required to cause these effects. Consumption of 7 grams licorice (containing 500 mg glycyrrhizin) per day for seven days has been shown to decrease serum testosterone levels in healthy men by blocking the enzymes needed to synthesize testosterone.47 However, in another study, a similar amount of licorice had only a small and statistically insignificant effect on testosterone levels.48 As a result of these possible side effects, long-term intake of high levels of glycyrrhizin is discouraged and should only be undertaken if prescribed by a qualified healthcare professional. Consumption of plenty of fresh fruits and vegetables to increase potassium intake is recommended to help decrease the chance of potassium deficiency. According to the German Commission E monograph, licorice is inadvisable for pregnant women as well as for people with liver and kidney disorders.49

De-glycyrrhizinated licorice extracts usually do not cause these side effects since 97% of the glycyrrhizin has been removed.

References

1. Whorwood CB, Shepard MC, Stewart PM. Licorice inhibits 11ß-hydroxysteroid dehydrogenase messenger ribonucleic acid levels and potentiates glucocorticoid hormone action. Endocrinology 1993;132:2287-92.

2. Soma R, Ikeda M, Morise T, et al. Effect of glycyrrhizin on cortisol metabolism in humans. Endocrin Regulations 1994;28:31-4.

3. Beil W, Birkholz C, Sewing KF. Effects of flavonoids on parietal cell acid secretion, gastric mucosal prostaglandin production and Helicobacter pylori growth. Arzneimittelforschung 1995;45:697-700.

4. Amer M, Metwalli M. Topical liquiritin improves melasma. Int J Dermatol 2000;39:299-301.

5. Morgan AG, McAdam WAF, Pacsoo C, Darnborough A. Comparison between cimetidine and Caved-S in the treatment of gastric ulceration, and subsequent maintenance therapy. Gut 1982;23:545-51.

6. Kassir ZA. Endoscopic controlled trial of four drug regimens in the treatment of chronic duodenal ulceration. Ir Med J 1985;78:153-6.

7. Bardhan KD, Cumberland DC, Dixon RA, Holdsworth CD. Clinical trial of deglycyrrhizinised liquorice in gastric ulcer. Gut 1978;19:779-82.

8. Das SK, Gulati AK, Singh VP. Deglycyrrhizinated licorice in aphthous ulcers. J Assoc Physicians India 1989; 37:647.

9. Brinckmann J, Sigwart H, van Houten Taylor L. Safety and efficacy of a traditional herbal medicine (Throat Coat) in symptomatic temporary relief of pain in patients with acute pharyngitis: a multicenter, prospective, randomized, double-blinded, placebo-controlled study. J Altern Complement Med 2003;9:285-98.

10. Ito M, Sato A, Hirabayashi K, et al. Mechanism of inhibitory effect of glycyrrhizin on replication of human immunodeficiency virus (HIV). Antivir Res 1988;10:289-98.

11. Hattori I, Ikematsu S, Koito A, et al. Preliminary evidence for inhibitory effect of glycyrrhizin on HIV replication in patients with AIDS. Antivir Res 1989;11:255-62.

12. Ikegami N, Akatani K, Imai M, et al. Prophylactic effect of long-term oral administration of glycyrrhizin on AIDS development of asymptomatic patients. Int Conf AIDS 1993;9:234 [abstract PO-A25-0596].

13. Blumenthal M, Goldberg A, Brinckmann J. Herbal Medicine: Expanded Commission E Monographs.Newton, MA: Integrative Medicine Communications, 1999.

14. Inada Y, Watanabe K, Kamiyama M, et al. In vitro immunomodulatory effects of traditional Kampo medicine (sho-saiko-to: SST) on peripheral mononuclear cells in patients with AIDS. Biomed Pharmacother 1990;44:17-9.

15. Piras G, Makino M, Baba M. Sho-saiko-to, a traditional kampo medicine, enhances the anti-HIV-1 activity of lamivudine (3TC) in vitro. Microbiol Immunol 1997;41:835-9.

16. Fujimaki M, Hada M, Ikematsu S, et al. Clinical efficacy of two kinds of kampo medicine on HIV infected patients. Int Conf AIDS 1989;5:400 [abstract no. W.B.P.292].

17. Li BQ, Fu T, Yan YD, et al. Inhibition of HIV infection by baicalin—a flavonoid compound purified from Chinese herbal medicine. Cell Mol Biol Res 1993;39:119-24.

18. Goso Y, Ogata Y, Ishihara K, Hotta K. Effects of traditional herbal medicine on gastric acid. Biochem Physiol 1996;113C:17-21.

19. Reed PI, Davies WA. Controlled trial of a carbenoxolone/alginate antacid combination in reflux oesophagitis. Curr Med Res Opin 1978;5:637-44.

20. Beil W, Birkholz C, Sewing KF. Effects of flavonoids on parietal cell acid secretion, gastric mucosal prostaglandin production and Helicobacter pylori growth. Arzneimittelforschung 1995;45:697-700.

21. Langmead L, Feakins RM, Goldthorpe S, et al. Randomized, double-blind, placebo-controlled trial of oral aloe vera gel for active ulcerative colitis. Aliment Pharmacol Ther 2004;19:739-47.

22. Weiss RF. Herbal Medicine. Beaconsfield, UK: Beaconsfield Publishers Ltd, 1989, 114-5.

23. Weizman Z, Alkrinawi S, Goldfarb D, et al. Efficacy of herbal tea preparation in infantile colic. J Pediatr 1993;122:650-2.

24. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics. New York: John Wiley & Sons, 1996, 222-4.

25. Baba S, Takasaka T. Double-blind clinical trial of sho-seiryu-to (TJ-19) for perennial nasal allergy. Clin Otolaryngol 1995;88:389-405.

26. Crawford AM. The Herbal Menopause Book. Freedom, CA: Crossing Press, 1996.

27. Hudson TS, Standish L, Breed C, et al. Clinical and endocrinological effects of a menopausal botanical formula. J Naturopathic Med 1997;7(1):73-7.

28. Hirata JD, Swiersz LM, Zell B, et al. Does dong quai have estrogenic effects in postmenopausal women? A double-blind, placebo-controlled trial. Fertil Steril 1997;68:981-6.

29. Nestel PJ, Pomeroy S, Kay S, et al. Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999;84:895-8.

30. Tice JA, Ettinger B, Ensrud K, et al. Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) Study: a randomized controlled trial. JAMA 2003;290:207-14.

31. van de Weijer PHM, Barentsen R. Isoflavones from red clover (Promensil®) significantly reduce menopausal hot flush symptoms compared with placebo. Maturitas 2002;42:187-93.

32. Crawford AM. The Herbal Menopause Book. Freedom, CA: Crossing Press, 1996.

33. Hudson TS, Standish L, Breed C, et al. Clinical and endocrinological effects of a menopausal botanical formula. J Naturopathic Med 1997;7(1):73-7.

34. Hirata JD, Swiersz LM, Zell B, et al. Does dong quai have estrogenic effects in postmenopausal women? A double-blind, placebo-controlled trial. Fertil Steril 1997;68:981-6.

35. Nestel PJ, Pomeroy S, Kay S, et al. Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999;84:895-8.

36. Tice JA, Ettinger B, Ensrud K, et al. Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) Study: a randomized controlled trial. JAMA 2003;290:207-14.

37. van de Weijer PHM, Barentsen R. Isoflavones from red clover (Promensil®) significantly reduce menopausal hot flush symptoms compared with placebo. Maturitas 2002;42:187-93.

38. Sheehan MP, Atherton DJ. One-year follow up of children treated with Chinese medical herbs for atopic eczema. Br J Dermatol 1994;130:488-93.

39. Sheehan MP, Rustin MH, Atherton DJ, et al. Efficacy of traditional Chinese herbal therapy in adult atopic dermatitis. Lancet 1992;340:13-7.

40. Sheehan M, Stevens H, Ostlere L, et al. Follow-up of adult patients with atopic eczema treated with Chinese herbal therapy for 1 year. Clin Exp Dermatol 1995;20:136-40.

41. Sheehan MP, Atherton DJ. A controlled trial of traditional Chinese medicinal plants in widespread non-exudative atopic eczema. Br J Dermatol 1992;126:179-84.

42. Keane FM, Munn SE, du Vivier AWP, et al. Analysis of Chinese herbal creams prescribed for dermatological conditions. BMJ 1999;318:563-4.

43. Baba M, Shigeta S. Antiviral activity of glycyrrhizin against varicella-zoster virus in vitro. Antivir Res 1987;7:99-107.

44. Baschetti R. Chronic fatigue syndrome and liquorice. New Z Med J 1995;108:156-7 [letter].

45. Murray MT. The Healing Power of Herbs. Rocklin, CA: Prima Publishing, 1995, 228-39.

46. Blumenthal M, Busse WR, Goldberg A, et al, eds. The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 161-2.

47. Armanini D, Bonanni G, Palermo M. Reduction of serum testosterone in men by licorice. New Engl J Med 1999;341:1158 [letter].

48. Josephs RA, Guinn JS, Harper ML, Askari F. Liquorice consumption and salivary testosterone concentrations. Lancet 2001;358:1613-4.

49. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 161-2.

Copyright © 2019 Healthnotes, Inc. All rights reserved. www.healthnotes.com

Learn more about Healthnotes, the company.

The information presented by Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2019.