Valerian root has never been tested for safety in pregnant women through a controlled clinical trial, which means no one can say with certainty whether it is safe or harmful during pregnancy. The animal research that does exist is mostly reassuring at normal doses, but a few findings raise enough concern that major health organizations and most clinicians advise pregnant women to avoid it. The picture gets more complicated once you look at what valerian’s active compounds actually do once they enter the body and whether they reach the fetus.
How Common Is Valerian Use During Pregnancy
Despite the lack of formal safety data, plenty of pregnant women take valerian. A multinational study covering more than 9,400 women across 23 countries found that about 29% reported using some form of herbal medicine during pregnancy, and valerian ranked among the most commonly used herbs alongside ginger, cranberry, and raspberry.1PubMed Central. Herbal medicine use in pregnancy: results of a multinational study A Swedish registry study of more than 860,000 women found a lower rate of herbal use overall, under 1%, but valerian was still among the top three herbs reported during early pregnancy.2PubMed. Use of herbal drugs during early pregnancy in relation to maternal characteristics and pregnancy outcome The Swedish data also turned up something interesting: the profile of women who chose valerian differed from those who chose other herbs, with valerian users more likely to smoke, for instance. That hints valerian may be filling a role as a self-prescribed anxiety or sleep aid in a population already dealing with stress.
How Valerian Works and Why That Matters for Pregnancy
Valerian’s calming effects come largely from a compound called valerenic acid, which enhances the activity of GABA receptors in the brain. GABA is the brain’s main “slow down” signal, and valerenic acid amplifies that signal in a way that is somewhat similar to how benzodiazepines work, though through a different binding site and generally with milder effects.3PubMed. Modulation of GABAA receptors by valerian extracts is related to the content of valerenic acid Extracts that are rich in valerenic acid produce this GABA-enhancing effect; polar extracts that lack it do not.
This mechanism matters for pregnancy because the fetal brain is actively developing GABA-based signaling circuits, and any substance that modulates those receptors could theoretically interfere with that process. It also matters because valerian contains other bioactive compounds beyond valerenic acid, including valepotriates, which have shown more worrying effects in lab studies. The safety question is really about which of these compounds reaches the fetus and at what concentration.
Valerenic Acid Crosses the Placenta
One of the most directly relevant pieces of research used a human placenta perfusion model to track whether valerenic acid could pass from the maternal side to the fetal side. It can. The study found that valerenic acid gradually accumulated in the fetal compartment while declining in the maternal compartment, reaching an equilibrium after about four hours. At that point, roughly 44% of the initial concentration was on the fetal side and about 45% remained on the maternal side.4Frontiers in Pharmacology. Transplacental passage of hyperforin, hypericin, and valerenic acid In practical terms, that means the primary active ingredient in valerian does not stay on your side of the placenta. Whatever effect valerenic acid has on GABA receptors, the fetus is exposed to it at a concentration close to the mother’s.
This does not automatically mean harm. Plenty of substances cross the placenta without causing damage. But it eliminates the comforting possibility that valerian might work on the mother without reaching the developing baby.
What Animal Studies Show About Fetal Development
Because no one has run a controlled trial in pregnant women, researchers have relied on animal models to look for signs of developmental toxicity. The results are somewhat encouraging, with an important caveat.
A rat study tested a specific valerian extract at doses up to 65 times the equivalent human dose and found no signs of maternal toxicity, no adverse effects on fertility, and no problems with fetal development.5Journal of Ethnopharmacology. A developmental toxicity-screening test of valerian However, the same study found toxicity when rat embryos were directly exposed to the extract in a culture dish, and the researchers noted that the extract they tested had a low pH that may have neutralized certain toxic compounds called valepotriates. They explicitly warned that other valerian preparations, especially those containing higher levels of valepotriates, could produce very different results.
A more recent and broader safety evaluation looked at valerian root aqueous extract in rats at several dose levels and found no significant changes in embryo formation, body weight of pregnant rats, or skeletal and organ development in the fetuses.6Journal of Ethnopharmacology. Safety evaluation of aqueous extract from Valeriana officinalis L. roots: Genotoxicity, acute, subchronic and teratology toxicity Together, these studies suggest that at doses in the range people typically use, valerian root extract is unlikely to cause gross structural birth defects. But “no structural defects visible in rats” is a low bar. Subtler effects on brain development or behavior would not necessarily show up in these tests.
A Possible Effect on Fetal Brain Zinc Levels
One mouse study looked beyond structural outcomes and measured trace minerals in fetal brain tissue. While valerian consumption during pregnancy had no significant effect on brain weight, cortical volume, or copper levels, it did significantly reduce zinc levels in the fetal brain.7PubMed. Effects of valerian consumption during pregnancy on cortical volume and the levels of zinc and copper in the brain tissue of mouse fetus Zinc is essential for normal brain development, playing a role in cell division, neurotransmitter function, and synapse formation. A single mouse study is far from proof that this happens in humans, but it flags a concern that goes beyond what the standard developmental toxicity tests would catch. No follow-up studies in humans have investigated this.
Effects on Uterine Muscle
Valerian has a long folk history as a remedy for menstrual cramps, and lab research supports the idea that it relaxes uterine muscle. A study using isolated strips of human uterine tissue (from non-pregnant women) found that valerian extracts and valepotriates inhibited contractions in a dose-dependent way, regardless of what chemical was used to trigger the contraction.8PubMed. Relaxing effects of Valeriana officinalis extracts on isolated human non-pregnant uterine muscle The relaxation appeared to be a direct effect on the muscle itself, not mediated through the usual receptor pathways.
During pregnancy, this uterine-relaxing property is a double-edged consideration. On one hand, excessive uterine relaxation could theoretically interfere with normal labor. On the other hand, the study used non-pregnant tissue, and the pregnant uterus behaves differently under different hormonal conditions. No research has tested how valerian affects uterine contractility during pregnancy specifically. The clinical significance of this finding remains unclear, but it is one more reason clinicians tend to err on the side of caution.
Valepotriates and Immune Cell Concerns
The safety picture for valerian is complicated by the fact that “valerian” is not a single compound. Different preparations contain different proportions of active ingredients, and some of those ingredients behave quite differently from valerenic acid. Valepotriates are a good example. While valerenic acid itself did not affect the division of human immune cells in a lab study, valtrate (a valepotriate) significantly suppressed immune cell proliferation even at very low concentrations.9Scientific Reports. Immunological evaluation of herbal extracts commonly used for treatment of mental diseases during pregnancy The same study found that at higher concentrations, valerian extract increased programmed cell death in lymphocytes.
These are test-tube findings, not evidence of what happens inside a pregnant woman’s body. But they underscore an important point: not all valerian products are equivalent. A water-based extract and an alcohol-based extract pull different compounds out of the root. A product high in valepotriates has a fundamentally different risk profile from one that is mostly valerenic acid. When someone asks “is valerian safe in pregnancy,” the honest answer depends partly on which preparation they are talking about, and most consumers have no way of knowing the valepotriate content of the supplement they bought.
Product Quality Adds Another Layer of Uncertainty
Even setting aside the active compounds, valerian supplements can contain unwanted contaminants. A study of 23 valerian root products sold in Spain found that six of them exceeded the European Pharmacopoeia’s cadmium limit of 0.1 mg/kg, with one sample reaching 0.23 mg/kg. The researchers ultimately concluded that at typical therapeutic doses, the metal levels did not pose a toxicological risk.10PubMed Central. Metal Content in Valeriana officinalis L. Root Commercialized in a Spanish Region (Tenerife, Canary Islands) Still, cadmium is a known developmental toxicant, and what constitutes a safe exposure level is lower during pregnancy than at other times. Herbal supplements are not regulated to pharmaceutical-grade purity standards in most countries, so batch-to-batch variation is a real concern.
Drug Interactions
Valerian has been flagged as a potential inhibitor of the liver enzyme CYP3A4 and of P-glycoprotein, a transporter protein that influences how drugs are absorbed and distributed. In theory, this could alter the blood levels of medications processed through these pathways, which includes a wide range of drugs commonly prescribed during pregnancy. In practice, a review of the evidence found that no clinically relevant interactions with medications metabolized by these enzymes have been observed.11Frontiers in Pharmacology. Use of Herbal Medicine by Pregnant Women: What Physicians Need to Know That said, the studies looking at this were not conducted in pregnant women, whose metabolism shifts substantially due to hormonal changes. If you are taking prescription medications during pregnancy, the interaction risk is one more reason to discuss valerian with your prescriber rather than adding it on your own.
Breastfeeding After Delivery
The question does not end at birth. Many women who considered valerian during pregnancy also wonder about using it while breastfeeding. A rat study tested valerian at several dose levels during the postpartum nursing period and found that while it did not cause obvious maternal toxicity or change nursing behavior, higher doses altered breast milk composition: the highest dose increased lactose, and the two higher doses reduced protein content in the milk. More concerning, the offspring of mothers given high-dose valerian showed impaired long-term memory later in life.12Brazilian Journal of Medical and Biological Research. Valerian treatment during the postpartum period alters breast milk composition and impairs long-term memory in female rat offspring The researchers concluded that high doses of valerian were not safe for breastfeeding in their animal model.
Rat metabolism and milk composition are not identical to human versions, so these results do not directly translate. But the study is one of the few that looked at valerian’s downstream effects on offspring development through lactation, and the memory impairment finding is hard to ignore. No equivalent human data exists.
What Works Instead for Pregnancy Insomnia
The main reason pregnant women reach for valerian is poor sleep, which is genuinely miserable and extremely common during pregnancy. If valerian is off the table, what actually helps? The strongest evidence points to cognitive behavioral therapy for insomnia, commonly called CBT-I. Unlike a pill or herb, it is a structured program that addresses the thinking patterns and sleep habits that keep insomnia going.
A meta-analysis of CBT-I studies in pregnant women found that it significantly improved sleep quality, reduced the time it took to fall asleep, and lowered both anxiety and depression scores compared to control groups.13PubMed. Efficacy of cognitive behavioural therapy for insomnia or sleep disturbance in pregnant women: A systematic review and meta-analysis Individual trials have been equally encouraging. One randomized trial found that 64% of women who received CBT-I achieved remission of their insomnia disorder, with a median time to remission of about a month.14PubMed Central. Cognitive Behavioral Therapy for Prenatal Insomnia: A Randomized Controlled Trial A trial of a digital CBT-I program, which women could complete on their own devices, found that participants gained an extra 32 minutes of sleep per night during pregnancy, and the benefit persisted after childbirth with an additional 40 minutes of nightly sleep compared to the control group.15PubMed Central. A randomized controlled trial of digital cognitive behavioral therapy for insomnia in pregnant women
The appeal of CBT-I during pregnancy is that it carries no chemical exposure risk, and the digital versions make it more accessible than traditional in-person therapy. It does require more effort than swallowing a capsule, and the results take a few weeks to build. But the evidence base for CBT-I in pregnancy is far stronger than anything supporting valerian for the same purpose.
Why the “Natural Means Safe” Assumption Breaks Down Here
Valerian occupies a tricky spot in public perception. It is a plant, it has been used for centuries, and it is sold over the counter without a prescription. All of that makes it feel harmless, especially compared to pharmaceutical sleep aids. But the logic of “natural therefore safe in pregnancy” has specific problems in this case. The active compound crosses the placenta and reaches the fetus at concentrations close to the mother’s. Different preparations contain wildly different mixtures of bioactive compounds, some of which show cytotoxic or immunosuppressive properties at relatively low concentrations. Supplement quality is unregulated in most markets. And none of this has been studied in a controlled setting in actual pregnant women.
The absence of evidence of harm is not the same as evidence of safety. The animal data is reassuring enough that a woman who took valerian before realizing she was pregnant probably does not need to panic. But the combination of placental transfer, variable product composition, fetal brain zinc depletion in at least one animal model, and the complete lack of human pregnancy trials means there is no responsible way to recommend it as a sleep aid during pregnancy when safer alternatives with strong evidence exist.