Ricinus communis

Castor oil/Drug Interactions:

  • AnalgesicsAnalgesics: In one human study, castor oil decreased pain more than ultrasound gel or Vaseline? during extracorporeal shock wave application, which was attributed to the fact that castor oil is cavitation free, meaning that there is not a sudden formation and collapse of low-pressure bubbles when forces are applied (4).
  • AntihypertensivesAntihypertensives: In a case series of women taking castor seeds as a contraceptive, some women had an elevated blood pressure (13).
  • Anti-inflammatoriesAnti-inflammatories: In animal research, ricinoleic acid, the main component of castor oil, exerted anti-inflammatory effects (28).
  • ContraceptivesContraceptives: Castor seeds protected against pregnancy in women for one year in an uncontrolled study (13).
  • DigoxinDigoxin: In humans, castor oil derivative polyoxyl 35 increased plasma digoxin concentrations (12).
  • DroperidolDroperidol: According to secondary sources, castor oil should not be taken in combination with droperidol (Inapsine?).
  • Drugs that affect electrolyte levelsDrugs that affect electrolyte levels: Castor oil alters water and electrolyte secretion. Theoretically, concurrent use of castor oil with agents that alter electrolytes may increase the risk of electrolyte imbalances.
  • ImmunosuppressantsImmunosuppressants: According to secondary sources, castor oil packs "boost the immune system," based on increased total lymphocyte counts and T-pan lymphocyte counts (T-11 cells) in a group of patients using castor oil packs.
  • LaxativesLaxatives: Castor oil is a stimulant laxative. Concurrent use with other laxatives may have additive effects and increase the risk of electrolyte imbalances.
  • LevomethadylLevomethadyl: According to secondary sources, castor oil should not be taken in combination with levomethadyl (Orlaam?).
  • P-glycoprotein-regulated agentsP-glycoprotein-regulated agents: In humans, Cremophor ELT, a castor oil derivative used to improve the solubilization of drugs and vitamins, has been shown to reverse multidrug resistance (MDR) mediated by p-glycoprotein (14). Cremophor ELT has been shown to inhibit this membrane transporter in vitro and in vivo (12).
  • Silver sulfadiazineSilver sulfadiazine: There is an unsubstantiated report that a topical spray composed of trypsin, balsam of Peru, and castor oil (marketed as AllanDerm-TT, Granul-dermT, OptaseT, RevinaT, Trypsin Complex, XenadermT, Balsa-Derm?, Granul?, or Granulex?) should not be taken with other skin products, especially silver sulfadiazine.

    • Castor oil/Herb/Supplement Interactions:

  • AnalgesicAnalgesics: In one human study, castor oil decreased pain more than ultrasound gel or Vaseline? during extracorporeal shock wave application, which was attributed to the fact that castor oil is cavitation free, meaning that there is not a sudden formation and collapse of low-pressure bubbles when forces are applied (4).
  • Anti-inflammatory agentsAnti-inflammatory agents: In animal research, ricinoleic acid, the main component of castor oil, exerted anti-inflammatory effects (28).
  • Cardiac glycosidesCardiac glycosides: In humans, castor oil derivative polyoxyl 35 increased plasma digoxin concentrations (12).
  • ContraceptivesContraceptives: Castor seeds protected against pregnancy in women for one year in an uncontrolled study (13).
  • DiureticsDiuretics: Castor oil alters water and electrolyte secretion. Theoretically, concurrent use of castor oil with agents that alter electrolytes (e.g., diuretics) may increase the risk of electrolyte imbalances.
  • Fat-soluble vitaminsFat-soluble vitamins: According to secondary sources, castor oil may impair the absorption of fat-soluble vitamins.
  • Hypertensives/HypotensivesHypertensives/Hypotensives: In a case series of women taking castor seeds as a contraceptive, some women had an elevated blood pressure (13)
  • ImmunomodulatorsImmunomodulators: According to secondary sources, castor oil packs "boost the immune system," based on increased total lymphocyte counts and T-pan lymphocyte counts (T-11 cells) in a group of patients using castor oil packs.
  • LaxativesLaxatives: Castor oil is a stimulant laxative. Concurrent use with other laxatives may have additive effects and increase the risk of electrolyte imbalances.
  • P-glycoprotein-regulated agentsP-glycoprotein-regulated agents: In humans, Cremophor ELT, a castor oil derivative used to improve the solubilization of drugs and vitamins, has been shown to reverse multidrug resistance (MDR) mediated by p-glycoprotein (14). Cremophor ELT has been shown to inhibit this membrane transporter in vitro and in vivo (12).

    • Castor oil/Food Interactions:

  • Insufficient available evidence.

    • Castor oil/Lab Interactions:

  • Blood pressureBlood pressure: In a case series of women taking castor seeds as a contraceptive, some women had an elevated blood pressure (13). In contrast, oral castor oil use did not cause significant changes in blood pressure in another study (9).
  • ElectrolytesElectrolytes: Castor oil alters water and electrolyte secretion. According to secondary sources, there have been reports of hypokalemia with castor oil. Other reports have reported castor oil to lower serum potassium and sodium levels but did not cause hypokalemia or hyponatremia (9).
  • Heart rateHeart rate: Oral castor oil use did not cause significant changes in heart rate (9). According to secondary sources, castor oil may cause an irregular heartbeat.
  • Lipid profileLipid profile: Cholesterol and phospholipid levels were not significantly altered following oral ingestion of castor seeds (13).
  • Tear physiologyTear physiology: In humans, an oil-in-water emulsion eyedrop containing castor oil caused a statistically significant decrease in tear evaporation rates without changing tear production or osmolality (8; 23). Tear interference grade decreased, rose bengal scores decreased, tear break-up time was prolonged, and meibomian gland orifice obstruction scores decreased, without any improvement in fluorescein staining scores (23).