Castor Oil
Ricinus communis
A Strong clinical evidenceA strong, fast-acting laxative with well-known efficacy for short-term constipation. Do not use it on your own to start labour.
Image: Herbadex Botanik Stüdyosu · Özel Üretim
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At a glance
Castor oil is pressed from the seeds of the castor plant (Ricinus communis). Ricinoleic acid released in the gut strongly stimulates bowel movement, acting within 2–6 hours. The seed itself contains deadly ricin, but processed oil contains none. Its popular use for hair and eyebrows rests on tradition, not evidence.
Updated: October 15, 2026
ℹ Compiled from standard pharmacognosy references and clinical literature summaries where no formal EMA monograph exists.
What is it used for?
A Strong clinical evidence
Strong clinical evidence: Supported by strong human clinical trials and well-established medicinal use monographs.
How do we rate evidence levels? →An effective stimulant laxative for short-term constipation. [1]
T Traditional use
Traditional use: Based on at least 30 years of documented traditional use rather than clinical trials.
How do we rate evidence levels? →Traditionally used for hair, eyebrow and eyelash care; faster growth has not been shown. [1]
How is it used?
Safety & interactions
Minimum age: 12 years
Duration limit: 3 days
- Do not use in pregnancy: it can trigger uterine contractions. Labour induction is only considered under medical supervision.
- Do not use with bowel obstruction, suspected appendicitis, inflammatory bowel disease or unexplained abdominal pain.
- Do not use long term: it causes water and potassium loss.
- Never eat castor seeds: they contain ricin and are poisonous.
Drug interactions
| Medicine / substance | Effect | Severity |
|---|---|---|
| Cardiac glycosides, diuretics | Potassium loss increases interaction risk. [2] | Moderate |
| All oral medicines | Rapid gut transit may reduce absorption. [2] | Minor |
Side effects
- Abdominal cramps, nausea, diarrhoea
- Loss of fluid and electrolytes
- Rarely allergic skin reaction
⚕ When to see a doctor
- If high fever, shortness of breath or purulent/bloody phlegm develops
- If symptoms do not improve within 1–2 weeks or worsen
- If severe abdominal pain, jaundice, rash or allergic reaction occurs
Did you know?
Castor seeds contain ricin, one of the most potent plant toxins, but it does not pass into cold-pressed oil. [1]
Frequently asked questions
Does castor oil grow eyelashes?
There is no scientific evidence; it only moisturises.
Does drinking castor oil start labour?
Some studies linked it to labour onset, but it causes nausea and diarrhoea; never use it without medical supervision.
How fast does castor oil work?
Usually within 2–6 hours; do not take it at bedtime.
Sources
- WHO Monographs on Selected Medicinal Plants (Volumes 1–4)World Health Organization · 2009
- Trease and Evans Pharmacognosy (16th Edition)Elsevier Health Sciences · 2009
Cite This Page
Castor Oil (Ricinus communis). Herbadex — Doğal Şifa Rehberi (2026). https://herbadex.com/en/herb/castor-oil/
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