Licorice / Glycyrrhiza glabra

The Basics

What is Licorice / Glycyrrhiza glabra?

Used as a sweetening and flavoring agent and as an herbal remedy for gastritis and upper respiratory tract infections. Modern cough syrups often include licorice extract.

Brand names for Licorice / Glycyrrhiza glabra

N/A

How Licorice / Glycyrrhiza glabra is classified

Complementary Therapies, Food, Phytotherapy, Plants, Medicinal

Licorice / Glycyrrhiza glabra During Pregnancy

Licorice / Glycyrrhiza glabra pregnancy category

Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Licorice / Glycyrrhiza glabra while pregnant

N/A

Taking Licorice / Glycyrrhiza glabra While Breastfeeding

What are recommendations for lactation if you're taking Licorice / Glycyrrhiza glabra?

Licorice (Glycyrrhiza glabra) root contains glycyrrhizin (also called glycyrrhizic acid or glycyrrhizinic acid) and a mixture of the potassium and calcium salts of glycyrrhizic acid. Glycyrrhizin is metabolized to the active glycyrrhetinic acid in the intestine. Deglycyrrhizinated licorice (DGL) has had glycyrrhizin removed. Licorice is a purported galactogogue, and is included in some Asian proprietary mixtures to increase milk supply; however, no scientifically valid clinical trials support this use. In fact, licorice usually reduces serum prolactin,[1] which might decrease milk production in the early stages of lactation. Women taking licorice have experienced elevated blood presure.[2] Galactogogues should never replace evaluation and counseling on modifiable factors that affect milk production.[3] Glycyrrhizin is detectable in the breastmilk of some women taking licorice, but studies measuring glycyrrhetinic acid have not been performed. Licorice has been used safely and effectively in combination with other herbs given to infants as a tea for the short-term treatment of colic.[4] However, two infants whose mothers had an excessive intake of an herbal tea that contained licorice had signs of anethole toxicity.[5] Because both of these papers reported on herbal mixtures, the effect(s) of licorice alone cannot be determined. Licorice and licorice extract are generally recognized as safe (GRAS) as foods by the U.S. Food and Drug Administration. Long-term, excessive use of licorice can cause hypertension, hypokalemia, and disturbances of adrenal hormones, and therefore should probably be avoided during nursing. Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products.

Maternal / infant drug levels

Licorice (Glycyrrhiza glabra) root contains glycyrrhizin (also called glycyrrhizic acid or glycyrrhizinic acid) and a mixture of the potassium and calcium salts of glycyrrhizic acid. Glycyrrhizin is metabolized to the active glycyrrhetinic acid in the intestine. Deglycyrrhizinated licorice (DGL) has had glycyrrhizin removed. Licorice is a purported galactogogue, and is included in some Asian proprietary mixtures to increase milk supply; however, no scientifically valid clinical trials support this use. In fact, licorice usually reduces serum prolactin,[1] which might decrease milk production in the early stages of lactation. Women taking licorice have experienced elevated blood presure.[2] Galactogogues should never replace evaluation and counseling on modifiable factors that affect milk production.[3] Glycyrrhizin is detectable in the breastmilk of some women taking licorice, but studies measuring glycyrrhetinic acid have not been performed. Licorice has been used safely and effectively in combination with other herbs given to infants as a tea for the short-term treatment of colic.[4] However, two infants whose mothers had an excessive intake of an herbal tea that contained licorice had signs of anethole toxicity.[5] Because both of these papers reported on herbal mixtures, the effect(s) of licorice alone cannot be determined. Licorice and licorice extract are generally recognized as safe (GRAS) as foods by the U.S. Food and Drug Administration. Long-term, excessive use of licorice can cause hypertension, hypokalemia, and disturbances of adrenal hormones, and therefore should probably be avoided during nursing. Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products.

Possible effects of Licorice / Glycyrrhiza glabra on milk supply

A woman with a history of excessive licorice intake had amenorrhea, severe headaches, hypertension, hypokalemia. She had elevated serum prolactin levels that remained abnormal for one month after licorice discontinuation and normalized by 6 months after discontinuation.[7]

In a study of 25 men and 25 women, the baseline and thyrotropin-stimulated serum prolactin levels were measured to determine normal serum prolactin values. Subjects who regularly ingested licorice had lower basal and lower stimulated serum prolactin concentrations.[1]

A traditional, nonstandardized decoction of peony and licorice roots called Shaoyao-Gancao-Tang in Chinese and Shakuyaku-Kanzo-To in Japanese was studied in women with elevated serum prolactin caused by long-term (>6 months) ingestion of risperidone. Patients received either bromocriptine 5 mg daily for 4 weeks followed by 4 weeks of 22.5 grams daily of the peony-licorice decoction (equivalent to 25 mg of glycyrrhetinic acid), or the same drugs in the reverse order. Evaluation of serum prolactin found that both treatments reduced serum prolactin by 21 to 28% from baseline at 4 and 8 weeks.[8]

Forty women who complained of an insufficient milk supply at 5 days postpartum were given a combination herbal supplement as 2 capsules of Lactare (Pharma Private Ltd., Madras, India; currently available from TTK Pharma, Chennai, India) 3 times daily. Each capsule contained wild asparagus 200 mg, ashwagandha (Withania somnifera) 100 mg, fenugreek 50 mg, licorice 50 mg, and garlic 20 mg. By day 4 of therapy, no infants required supplementary feeding. Infants were weighed before and after each feeding on the fifth day of maternal therapy to determine the amount of milk ingested. On the day of the test weighing, infants’ milk intake averaged 388 mL, and the fluid and caloric intake was considered adequate.[9] This study cannot be considered as valid evidence of a galactogogue effect of these herbs because it lacks randomization, blinding, a placebo control, and maternal instruction in breastfeeding technique. Additionally, infants were breastfed only 6 to 8 times daily, which is insufficient to maximize milk supply at this stage of lactation.

Women who were between 14 and 90 days postpartum and reported lactation failure were given instructions on breastfeeding technique and encouraged to exclusively breastfeed. If their infant had gained less than 15 grams in 1 week, they were randomized to receive either two tablespoonfuls of a mixture containing wild asparagus or an identical placebo for 4 weeks. In each 100 grams, the mixture contained Asparagus racemosus 15 grams, Anethum soiva 1 gram, Ipomea digitata 1 gram, Glycyrrhiza glabra 1 gram, Spinacia oleracea 2.5 grams, Cuminum cyminum 0.5 gram, and Panchatrinamol 1 gram. Of the 64 women randomized, 11 did not complete the trial. Serum prolactin measurements were made before a morning nursing before treatment and after 4 weeks of treatment. Infant weight gains and the number of supplemental feedings were recorded initially and after 4 weeks of therapy. No differences were found in the changes in serum prolactin, infant weight gain or amount of supplementation between the treatment and placebo groups after 4 weeks of therapy. No side effects or changes in liver function tests occurred during the study.[10]

A study in Japan compared the use of a mixture of 13 herbs, including licorice, to ergonovine for their effects on lactation and serum prolactin in postpartum women. The herbal mixture, called Xiong-gui-tiao-xue-yin, was given in a randomized fashion to 41 women in a dose of 2 grams of a dried aqueous extract 3 times daily. A comparable group of 41 women were randomized to receive methylergonovine 0.375 mg daily. Therapy was started on the day of delivery, but the duration of therapy was not specified. Plasma oxytocin and prolactin were measured on days 1 and 6; milk volumes were measured daily, although the method of measuring milk volume was not specified. Serum prolactin was higher on days 1 and 6 in the women who received the herbals; plasma oxytocin was lower on day 1 in the women who received the herbal, but not different on day 6. Milk volumes were greater on days 4, 5, and 6 in women who received the herbal mixture.[11] This study has serious flaws that make its interpretation impossible. First, milk volume measurement is subject to considerable variability depending on the measurement method used, but the method was not specified. Second, methylergonovine has caused decreases in serum prolactin and milk production in some studies.[12][13] Because of the lack of a placebo group, the differences found could be a negative effect of methylergonovine rather than a positive effect of the herbal preparation. Because this study used a multi-ingredient combination products in which licorice was only one component, the results might be different from studies in which licorice was used alone.

In an uncontrolled, non-blinded multicenter study in India, 1132 patients who reported inadequate milk supply were give a mixture (Lactancia, Corona Remedies Pvt. Ltd.) To take in a dose of 30 grams twice daily. The product contains Asparagus racemosus (wild asparagus, shatavari), Cuminum cyminum (cumin) , Glycyrrhiza glabra (licorice), Spinacia oleracea (spinach) as well as amino acids, vitamins, minerals and DHA. Most of the mothers (1049) had improved lactation and increased infant weight.[14] However, with no placebo control group, results cannot be attributed to the product.

Possible alternatives to Licorice / Glycyrrhiza glabra

None listed