Musta and Pregnancy: What the Fetal Growth Study Shows

Musta (nagarmotha, Cyperus rotundus) is discouraged during pregnancy, as a precaution. Our musta dangers article already mentioned this caution briefly, tied to the root's traditional emmenagogue use. A more recent study on fetal growth lends modern data to support that reservation.

Here is what the study shows, and what to take from it without overstating or downplaying it.

Why is musta traditionally avoided in pregnancy?

Ayurvedic pharmacopeia classes musta among herbs with emmenagogue action, meaning it may stimulate uterine contractions and promote menstruation. This action, sought outside pregnancy to regulate an irregular cycle, becomes a reason for avoidance once a pregnancy is underway or being considered: a herb that acts on uterine contractility has no place in a body carrying a pregnancy.

What does the study on fetal growth show?

A study by Busman, Nurcahyani, Farisi, Kanedi and Prabiwi Dita published in 2020 in GSC Biological and Pharmaceutical Sciences tested an extract of Cyperus rotundus tuber in pregnant rats, at doses of 22.5, 45 and 90 mg/kg, administered from gestation day 6 to day 18 (see on Google Scholar). The results show a decrease in fetal weight and length, proportional to the dose received by the mother.

This is a preclinical study, conducted in animals at doses that do not necessarily correspond to modest traditional human use. It does not, therefore, allow a conclusion of identical risk in pregnant women. But it provides a concrete signal, consistent with the traditional caution already recommended: nothing justifies taking that risk during pregnancy, a period where no margin of uncertainty is acceptable.

Summary by situation

Situation	Recommendation
Pregnancy, any trimester	Avoid as a precaution, given traditional emmenagogue action and a preclinical signal on fetal growth.
Trying to conceive	Caution recommended as well, until pregnancy is confirmed or ruled out.
Breastfeeding	Insufficient data; avoid as a precaution given the lack of evidence.
Irregular cycle outside pregnancy	Traditional use possible at modest doses; see the dedicated article and how to choose it well.

What to do about digestive trouble or an irregular cycle during pregnancy?

Digestive trouble and cycle irregularities around conception should not be self-treated with musta. Persistent diarrhea, marked bloating, or a concern about the cycle deserve a midwife's or doctor's advice, who can suggest care appropriate for pregnancy.

Precautions

This article complements our Ayurveda and Pregnancy guide, which lists practices and herbs to avoid during this period. For general precautions applicable to all herbs on this site, see our safety and precautions guide. In the absence of reassuring data in pregnant women, the rule stays simple: abstain, and speak with a healthcare professional before considering anything.