St. John's wort (Hypericum perforatum) and breastfeeding: plasma and breast milk concentrations of hyperforin for 5 mothers and 2 infants

J Clin Psychiatry. 2006 Feb;67(2):305-9. doi: 10.4088/jcp.v67n0219.


Background: Herbal preparations for depression, such as St. John's wort, are often preferred over pharmaceutical preparations by mothers and midwives after childbirth because these preparations are available to patients as over-the-counter "natural" treatments and are popularly assumed to be safe. The only existing report on St. John's wort excretion into human milk showed that only 1 active component (hyperforin) was detectable in breast milk, but was not detectable in the infants' plasma. Another report found more cases of minor problems in infants breast-fed by women taking St. John's wort. However, significance was reached only in comparison with disease-matched women (p<.01), not healthy controls (p=.20).

Method: Five mothers who were taking 300 mg of St. John's wort 3 times daily (LI 160 [Jarsin], Lichtwer Pharma GmbH; Berlin, Germany) and their breastfed infants were assessed. Thirty-six breast milk samples (foremilk and hindmilk collected during an 18-hour period) and 5 mothers' and 2 infants' plasma samples were analyzed for hyperforin levels by tandem mass spectrometry (LC/MS/MS; limit of quantification=0.1 ng/mL). Data were gathered from January 2001 to February 2002.

Results: Hyperforin is excreted into breast milk at low levels. However, the compound was at the limit of quantification in the 2 infants' plasma samples (0.1 ng/mL). Milk/plasma ratios ranged from 0.04 to 0.13. The relative infant doses of 0.9% to 2.5% indicate that infant exposure to hyperforin through milk is comparable to levels reported in most studies assessing anti-depressants or neuroleptics. No side effects were seen in the mothers or infants.

Conclusion: These results add to the evidence of the relative safety of St. John's wort while breast-feeding found in previous observational studies.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Breast Feeding* / adverse effects
  • Bridged Bicyclo Compounds / pharmacokinetics
  • Bridged Bicyclo Compounds / therapeutic use
  • Depressive Disorder / blood
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / metabolism
  • Female
  • Humans
  • Hypericum / adverse effects
  • Hypericum / metabolism*
  • Infant
  • Mass Spectrometry
  • Maternal Exposure / adverse effects
  • Maternal-Fetal Exchange
  • Milk, Human / chemistry*
  • Milk, Human / metabolism
  • Phloroglucinol / analogs & derivatives*
  • Phloroglucinol / pharmacokinetics
  • Phloroglucinol / therapeutic use
  • Phytotherapy / adverse effects
  • Phytotherapy / methods*
  • Plant Preparations / analysis
  • Plant Preparations / blood
  • Plant Preparations / pharmacokinetics*
  • Pregnancy
  • Terpenes / pharmacokinetics*
  • Terpenes / therapeutic use


  • Bridged Bicyclo Compounds
  • Plant Preparations
  • Terpenes
  • Phloroglucinol
  • hyperforin