Summary of Use during Lactation

Stinging nettle (Urtica dioica and Urtica urens) preparations have been used in nursing mothers orally as a postpartum as a "tonic" for treating anemia.[1,2] It is also a purported galactogogue.[2-7] Hypothetically, a galactogogue effect might be due to the binding of sex hormone-binding globulin by polar extracts of Urtica dioica causing elevated serum estrogen levels, by histamine-induced prolactin release, or by serotonin-induced release of thyrotropin-releasing hormone.[8] However, no scientifically valid clinical trials support the safety or efficacy in nursing mothers or infants for any use. Galactogogues should never replace evaluation and counseling on modifiable factors that affect milk production.[9] Although stinging nettle is generally well tolerated in adults, topical use can cause urticaria when applied topically, and application on one mother's nipple resulted in allergic skin rash in her breastfed infant. It is probably best not to apply stinging nettle topically to the breast while breastfeeding.

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. More detailed information about dietary supplements is available elsewhere on the LactMed Web site.

Drug Levels

Maternal Levels. Relevant published information was not found as of the revision date.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

A 17-day-old exclusively breastfed infant was admitted to the hospital with an urticarial rash on the chest, back, and upper extremities. The infant's mother had reportedly applied water boiled with stinging nettles for cracked nipple twice a day before and after each breastfeeding for 2 days. Total IgE and specific IgE levels for stinging nettle were high in the mother and infant. The infant's rash improved upon cessation of breastfeeding. Breastfeeding was resumed 2 days later without the use of stinging nettle on the nipple and the rash did not recur. At 2 months of age, skin prick testing in the infant was positive for stinging nettle, but no other allergen tested positive.[10] Stinging nettle exposure was the probable cause of the rash.

Effects on Lactation and Breastmilk

Single cases of gynecomastia in a man and galactorrhea in a woman were reported after ingesting nettle as a tea for 4 weeks prior to seeking medical advice. Serum hormones were normal in the man, but serum estradiol was very high, prolactin was slightly elevated, and LH and FSH were low in the woman. Both conditions reversed 4 to 6 weeks after stopping the tea. The case reports were from Turkey where ingestion of nettle is common. No analysis of the tea was performed to test for foreign substances.[11] The relevance of these findings with respect to breastfeeding are not known. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

A randomized trial assigned mothers of preterm infants to receive either a purported herbal galactogogue tea twice daily, a fruit tea twice daily or nothing. The galactogogue tea mixture (Natal, Hipp [Turkey]) contained 1% stinging nettle as well as melissa, caraway, anise, fennel, goat's rue, and lemon grass in unspecified amounts. All mothers received similar breastfeeding advice from the same nurse and two groups were told that the tea would increase milk production, but compliance with the study teas was not assessed. Mother used breast pumps to extract and measure their milk and output on day 1 and day 7 of the study were compared. Although the increase in volume of extracted milk was greater in the galactogogue tea group, there was no difference in maternal serum prolactin between the groups at 7 days. No difference in infant weight gain was seen between groups, although the authors stated that additional supplementation was provided to all infants in addition to the pumped milk.[12] The study was not blinded, the randomization method was not stated, intent-to-treat analysis was not performed, and some of the numerical results were internally inconsistent, so the quality of the study was poor.

A woman was taking Urtica dioica 500 mg (doses/day not stated) for environmental allergies. She was also taking Echinacea intermittently and had a contraceptive implant of etonogestrel in place for the past 1.5 years. She had begun the stinging nettle about 1 month prior to noticing an intermittent colostrum-like discharge from both breasts. Serum prolactin, thyroid-stimulating hormone, and a metabolic panel were all were within normal limits. One week after discontinuing the stinging nettle supplement, her galactorrhea resolved.[8]

References

1.

Dennehy C, Tsourounis C, Bui L, et al. The use of herbs by California midwives. J Obstet Gynecol Neonatal Nurs. 2010;39:684–93. [PubMed: 21044150]

2.

Scott CR, Jacobson H. A selection of international nutritional and herbal remedies for breastfeeding concerns. Midwifery Today Int Midwife. 2005;75:38–9. [PubMed: 16320878]

3.

Petrie KA, Peck MR. Alternative medicine in maternity care. Prim Care. 2000;27:117–36. [PubMed: 10739460]

4.

Belew C. Herbs and the childbearing woman. Guidelines for midwives. J Nurse Midwifery. 1999;44:231–52. [PubMed: 10380443]

5.

Yarnell E. Botanical medicine in pregnancy and lactation. Altern Complement Ther. 1997;3(April):93–100.

6.

Abascal K, Yarnell E. Botanical galactagogues. Altern Complement Ther. 2008;14:288–94. [CrossRef]

7.

Winterfeld U, Meyer Y, Panchaud A, et al. Management of deficient lactation in Switzerland and Canada: A survey of midwives' current practices. Breastfeed Med. 2012;7:317–8. [PubMed: 22224508]

8.

Easton L, Vaid S, Nagel AK, et al. Stinging nettle (Urtica dioica): An unusual case of galactorrhea. Am J Case Rep. 2021;22:e933999. [PMC free article: PMC8669525] [PubMed: 34876549]

9.

Brodribb W. ABM Clinical Protocol #9. Use of galactogogues in initiating or augmenting maternal milk production, second revision 2018. Breastfeed Med. 2018;13:307–14. [PubMed: 29902083]

10.

Uslu S, Bulbul A, Diler B, et al. Urticaria due to Urtica dioica in a neonate. Eur J Pediatr. 2011;170:401–3. [PubMed: 20953796]

11.

Sahin M, Yilmaz H, Gursoy A, et al. Gynaecomastia in a man and hyperoestrogenism in a woman due to ingestion of nettle (Urtica dioica). N Z Med J. 2007;120:U2803. [PubMed: 18264183]

12.

Özalkaya E, Aslandogdu Z, Ozkoral A, et al. Effect of a galactagogue herbal tea on breast milk production and prolactin secretion by mothers of preterm babies. Niger J Clin Pract. 2018;21:38–42. [PubMed: 29411721]

Substance Name

Stinging Nettle

Scientific Name

Urtica dioica Urtica urens

Drug Class

Breast Feeding

Lactation

Complementary Therapies

Galactogogues

Phytotherapy

Plants, Medicinal