Does castor oil or sesame oil cause severe inflammation when administered subcutaneously?

Castor Oil and Sesame Oil in Subcutaneous Injection: Severe Inflammation Risk

Castor oil causes life-threatening multisystem organ failure when injected subcutaneously in large volumes and should never be used for subcutaneous injection, while sesame oil causes chronic granulomatous inflammation (oleomas) requiring surgical excision. 1, 2

Castor Oil: Extreme Toxicity Profile

Castor oil injection subcutaneously is contraindicated due to documented catastrophic outcomes. A case report demonstrates that 500 mL bilateral subcutaneous castor oil injection resulted in 1:

• Immediate severe local inflammation with pain and erythema
• Multisystem organ failure within 12 hours including:
  • Hemolysis with persistently hemolyzed blood samples
  • Thrombocytopenia
  • Hepatitis with jaundice
  • Anuric renal failure requiring 1.5 months of dialysis
  • Respiratory distress requiring mechanical ventilation
  • Fever and tachycardia

The systemic absorption of castor oil was confirmed by detection of ricinine (the Ricinus communis biomarker) in urine at 41 ng/mL, proving that subcutaneous castor oil enters systemic circulation and causes toxicity 1.

Sesame Oil: Chronic Granulomatous Inflammation

Sesame oil causes persistent subcutaneous oleomas (oil-induced granulomas) that manifest months after injection and require surgical removal. 2

Clinical Presentation

• Subcutaneous nodules appear 9 months post-injection in documented cases 2
• Ultrasound reveals multiple low-reflecting round nodular areas up to 1 cm diameter 2
• Histopathology shows cysts filled with oily material surrounded by granulomatous tissue 2
• Surgical excision is required for treatment 2

Pharmacokinetic Evidence

The prolonged tissue retention of sesame oil explains the chronic inflammatory response 3:

• Half-life at injection site is 23 days after intramuscular or subcutaneous administration 3
• No significant difference in disappearance rate between intramuscular versus subcutaneous routes 3
• Spreading effect and reflux through injection canal contribute to prolonged local exposure 3

Important Caveats

Context Matters for Sesame Oil

While sesame oil causes severe local inflammation when injected subcutaneously for cosmetic purposes, controlled subcutaneous sesame oil injection in research settings (1-4 mL/kg) demonstrated anti-inflammatory systemic effects without reported local complications 4, 5. However, this does not translate to clinical safety for cosmetic or therapeutic human use, as:

• Research doses were calculated and controlled 4
• The cosmetic injection case involved uncontrolled large volumes 2
• Granuloma formation is the expected outcome in real-world cosmetic use 2

Castor Oil in Guidelines

Castor oil is mentioned in gastrointestinal guidelines solely as an oral stimulant laxative acting on small bowel fluid secretion, but is "rarely used" due to better alternatives 6. This guideline provides no support for parenteral use and the context is entirely different from injection.

Clinical Bottom Line

Both oils cause severe inflammation via different mechanisms:

• Castor oil: Acute systemic toxicity with multiorgan failure 1
• Sesame oil: Chronic granulomatous foreign body reaction 2

Neither oil should ever be used for subcutaneous injection in clinical practice. The only exception would be highly controlled research protocols with appropriate ethical oversight and monitoring 4.