Ashwagandha

Pregnancy

NCCIH says ashwagandha should be avoided during pregnancy. BfR advises against use in pregnant people because human data are lacking, while ANSES cites suspected adverse effects on fetal development and also describes a lack of well-characterized data. ODS reports that some experts warn of a possible spontaneous-abortion effect, but says the American Herbal Pharmacopoeia stated its report was misrepresented and that there is no evidence that root ashwagandha causes abortion. The basis for the reported human miscarriage concern was not verified in the primary studies reviewed. A 2015 prenatal study exposed Wistar rats to a methanolic root extract at 500, 1,000, or 2,000 mg/kg/day from gestation day 5 to 19; the authors reported no maternal or fetal effects or external, skeletal, or visceral malformations. A 2025 reproductive and developmental study tested an aqueous root extract at the same dose levels in Wistar rats. Each group began with 10 males and 13 females; female rats received the extract through pre-mating, pregnancy, and lactation, and pups were followed through postpartum day 13. The authors reported no treatment-related differences in measured body weight, reproductive-organ weight, T4 or TSH levels, or pup outcomes. They also reported dam and pup deaths during lactation in all groups and did not attribute them to treatment. The 2025 study had no positive control, did not measure T3, and did not include a genotoxicity study. A 2026 open-label, randomized, single-center trial enrolled 70 pregnant people in the second trimester, with 63 completing 12 weeks. Participants received KSM-66 root extract, 300 mg twice daily, plus standard hematinic therapy, or standard therapy alone. The authors reported no adverse events or serious adverse events, but fetal health outcomes were not assessed. The study excluded people with a history of miscarriage, preterm labor, and several pregnancy complications. This trial gives very limited maternal data for the second trimester, not fetal-outcome evidence or evidence for the first or third trimester.

Breastfeeding

LactMed reports no data on Withania components in human milk or on use in nursing parents or infants, and advises avoiding it especially while nursing a newborn or preterm infant. NCCIH also says it should not be used while breastfeeding. BfR explicitly says its advice for pregnant and breastfeeding people reflects a lack of data. ANSES recommends avoiding supplements during breastfeeding as a precaution because data for nursing women are lacking. LactMed mentions a combination herbal product that included ashwagandha, but says the uncontrolled study cannot establish a milk-supply effect; it was not an ashwagandha-only study. The 2025 rat study dosed female rats during lactation and followed pups to postpartum day 13, measuring growth and other developmental markers, but it did not test human milk transfer or infant outcomes. The authors reported lactation-period deaths across all study groups and did not attribute them to treatment. No human milk-level study or direct human breastfeeding outcome study was identified in the reviewed sources.

What was tested

The 2015 animal study gave a methanolic root extract to pregnant Wistar rats during gestation days 5 to 19, at 500, 1,000, or 2,000 mg/kg/day, and examined maternal and fetal outcomes. The 2025 animal study used an aqueous KSM-66 root extract at the same dose levels, with female rats dosed across pre-mating, pregnancy, and lactation; offspring measures continued through postpartum day 13. The 2026 human study was a 12-week, open-label, single-center comparison in 70 second-trimester participants. It measured maternal blood counts, stress and sleep questionnaires, adverse events, and maternal liver, kidney, heart, and thyroid laboratory markers. It did not assess fetal health outcomes. No human study of ashwagandha during breastfeeding was found in the reviewed sources.