Castor Oil and labour induction
What 5 graded rows on castor oil agree on for labour induction, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Castor Oil page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Castor Oil page, with its PubMed record.
Your question
Castor Oil and labour induction
5 rows · 1,496 peopleSplit. 2 rows found an improvement, 1 found no difference and 2 had mixed results.
- CGrade C× 4
- ∅No effect× 1
- Rows
- 5
- Trials
- 14
- People
- 1,496
- Pooled reviews may count some twice
Where they differ
From the rowsThe best-graded row, grade C, is a meta-analysis of 902 people (2022) and reported mixed results. 1 row is graded No effect, our grade for adequately powered trials that found no effect.
The row that found no difference is a pooled review of several trials; the 2 rows that found an improvement are single studies.
The 2 rows that found an improvement are newer (2022 to 2026) than the row that found no difference (2013).
2 rows with mixed results are left out of this comparison.
The rows
2 improved · 1 no difference · 2 mixed- CGrade CLabour within 48 hours at 40 to 41 weeks · Improved
RCT · n 210 · 2026 · Women at 40+0 to 41+0 weeks in two Enugu hospitals (Nigeria); 70 per arm
Single dose (amount not stated in the abstract) · Single dose
Labour within 48 hours in 52.9% with castor oil vs 24.3% with expectant care (OR 3.50); membrane sweeping 62.9%, not significantly different from castor oil.
- CGrade CLabour onset within 24 hours after a previous caesarean · Improved
RCT · n 70 · 2022 · Women with one previous caesarean attempting vaginal birth (Egypt)
60 ml once · Single dose
Labour started within 24 hours in 45.7% with castor oil vs 8.5% with placebo; successful vaginal birth 65.7% vs 48.5%.
- ∅No effectCaesarean birth and newborn outcomes after castor oil for labour · No difference
Meta-analysis, 3 studies · n 233 · 2013 · Women in the third trimester in 3 trials
Single dose · Single dose
No difference in caesarean section (RR 2.04, 95% CI 0.92 to 4.55), instrumental delivery, meconium-stained liquor or low Apgar score; all women who drank castor oil felt nauseous (RR 59.92).
- CGrade CLabour onset and cervical ripening late in pregnancy · Mixed
Meta-analysis, 8 studies · n 902 · 2022 · Pregnant women at or past term in 8 studies
Single oral dose (amounts varied by study) · Single dose
Labour induction odds ratio 11.67 (95% CI 3.34 to 40.81) and higher Bishop scores (SMD 1.64) versus control; the reported Bishop-score confidence interval (1.67 to 2.11) does not contain its own point estimate.
- CGrade CEntering active labour within 48 hours, post-date pregnancy · Mixed
RCT · n 81 · 2018 · Low-risk post-date singleton pregnancies, outpatient
60 ml once · Single dose
Benefit only in women who had given birth before (hazard ratios 2.78 to 3.29 at 24 to 48 hours); no effect in first-time mothers and no difference in complications.