Clary Sage Oil and Labor: What the Studies Actually Show

Clary sage oil does not start labor, and none of the sources we could read says it does. The claim travels because a few small studies measured a hormone or a mood during labor in women who were already being cared for by midwives, and because blends containing clary sage turn up in birth-unit aromatherapy. This article goes through those studies number by number, and it ends where it has to: if you are pregnant, a midwife or OB-GYN decides what goes near your labor.

Clary Sage Essential Oil bottle

Clary Sage Essential Oil

Our own Clary Sage Essential Oil, in sizes from 0.5 oz to bulk.

From $19.99

Shop Now →

The claim, taken apart

Three separate ideas get blurred together: that clary sage oil brings on labor, that it strengthens contractions that have already begun, and that it calms anxiety during labor. Different studies speak to each, and none of them is a trial of clary sage oil alone in labor. Many aromatherapy studies use blends, so any effect belongs to the blend, not to clary sage by itself.

The midwifery audit everyone cites

The study behind most "clary sage in labor" talk is an evaluation by Burns et al., J Altern Complement Med, 2000 (the journal is sometimes misquoted as Midwifery). It covered 8,058 mothers at a large British teaching hospital between 1990 and 1998, set against 15,799 mothers from the same unit who were not given aromatherapy. Women were offered aromatherapy for anxiety, pain, nausea or vomiting, or to strengthen contractions. Over 50% rated it helpful and 14% unhelpful, and 1% reported associated symptoms. The authors wrote that it "may have the potential to augment labour contractions for women in dysfunctional labour".

What it does not give us: the abstract does not break the oils down, so it does not say how many women received clary sage or what it did. We could not read the full text this session. The comparison group was drawn from routine unit audit data, not randomized, so the design cannot separate aromatherapy from the other changes in the unit over eight years (the authors note pethidine use fell from 6% to 0.2% in that period). It is evidence that a hospital used aromatherapy and that women liked it, not that an oil moves a cervix.

The oxytocin studies: small, and they undercut the claim

The more direct test is measuring oxytocin, the hormone that drives contractions. A 2017 Japanese pilot (Tadokoro et al., BMC Research Notes) had 11 women with singleton pregnancies at 38 to 40 weeks inhale clary sage oil diluted 50-fold in propylene glycol for 20 minutes (5 women) or a control without the oil (6 women). Salivary oxytocin 15 minutes later rose in 3 of the 5 in the clary group, and in 2 of the 6 controls; it was unmeasurable in 2 women in each group. Uterine contractions were not observed in either group. That is a feasibility study of the method, with a group too small for any conclusion.

The same team ran a larger 2023 non-randomized study (Tadokoro et al., Int J Environ Res Public Health) in 82 low-risk term women: a footbath with clary sage and lavender oils (28 women), a jasmine footbath (27) or no oil (27). Oxytocin rose significantly within the clary sage and lavender group (p = 0.035), but the change did not differ significantly from the control group, and uterine contractions and cortisol did not differ either. The authors attribute the null comparison to small numbers. Note that this tested a blend by footbath, and that the authors state the goal as examining whether aromatherapy stimulates labor, not that it does.

Reading these together: the human data on "clary sage and oxytocin" is 11 women inhaling and 28 women in a footbath blend, with no significant difference from control in the one adequately sized comparison, and no contractions in either study. A plain verdict: the induction claim has no support from these studies.

What the broader reviews found

The Cochrane review of aromatherapy for pain in labour (Smith, Collins, Crowther, 2011) searched to October 2010 and found two randomized trials with 535 women in total. They found no difference in pain intensity, assisted vaginal birth, caesarean, pain-relief use or length of labour, with low risk of bias, and the authors concluded that more research was needed before recommendations could be made. A 2019 systematic review on anxiety in first-stage labor (Ghiasi et al., J Caring Sci) found 14 published and 2 unpublished papers from Iran, Egypt, Korea and Italy; clary sage was among the oils used in 3 of them (lavender in 5). Most studies reported lower anxiety, and the authors asked for more rigorous research. Different questions, different dates, and different conclusions: the 2011 review is about pain and says no difference, the 2019 one is about anxiety and says mostly positive, and neither isolates clary sage.

What the health services say

The NHS page on inducing labour says induction is offered if labour has not begun naturally by 41 weeks, and that "there are no proven ways of starting your labour yourself at home", with herbal supplements lacking safety information and potentially harmful to you or your baby. The medical methods it lists, such as a membrane sweep after 39 weeks, hormones or a balloon catheter, are done by a midwife or doctor. One NHS maternity service describes clary sage as "contraindicated in pregnancy until after 37 weeks gestation", and offers a labour aromatherapy consultation from 37 weeks. That is one trust's service page, not national policy, but it shows where supervised use sits: a trained person, late in pregnancy, as part of a care plan.

Our position

Our own pages tell readers to avoid clary sage oil during pregnancy, and we sell the oil undiluted and make no health claims. We do not recommend it for labor, and we would not put a dilution on this page, because the arithmetic of a percentage is the easy part and the judgment about a pregnancy is not ours to make. If your midwife or OB-GYN offers a supervised aromatherapy plan late in pregnancy and names an oil, follow them, and ask where the oil comes from. Do not try to start labor with oil, with or without a carrier. If you are past your due date and wondering about options, the people to ask are your midwife or obstetrician, who can offer sweeping or induction.

For the broader pregnancy question, see our pregnancy article, and for women's health topics generally, the women's health overview. If you are nursing afterward, read the breastfeeding sources, and for reactions to the oil on skin, side effects.

Clary Sage Essential Oil bottle

Clary Sage Essential Oil

Clary Sage Essential Oil from our own shop, in sizes from 0.5 oz to bulk.

From $19.99

Shop Now →

Sources & Further Reading