Lemongrass Oil

Lemongrass oil, extracted from the leaves and stalks of the lemongrass plant (Cymbopogon citratus or Cymbopogon flexuosus), is a potent essential oil known for its antimicrobial, anti-inflammatory, and anxiolytic properties. Native to tropical regions of Asia, Africa, and Australia, lemongrass has been used for centuries in culinary and medicinal traditions to support digestion, reduce stress, and combat infections. As a concentrated oil, it is widely used in aromatherapy, topical applications, and supplements, with research exploring its benefits for skin health, mood regulation, and microbial resistance. This article examines lemongrass oil’s chemical characteristics, sources, historical and contemporary uses, nutritional profile, pharmacological properties, clinical evidence, side effects, and practical applications.

Chemical Characteristics and Sources

Lemongrass oil is a volatile concentrate with distinct properties:

• Chemical Composition: Rich in citral (60–85%, a mix of geranial and neral), geraniol, myrcene, and limonene. Contains minor compounds like citronellal, linalool, and β-caryophyllene. Provides its characteristic lemony scent.
• Physical Properties: Pale yellow to amber liquid, insoluble in water but soluble in alcohol and carrier oils, with a strong, citrusy aroma. Volatile and light-sensitive; stable when stored in dark, airtight containers.
• Natural Source: Leaves and stalks of lemongrass, a perennial grass in the Poaceae family. Grown in India, Sri Lanka, Brazil, and Southeast Asia.
• Bioavailability: Citral and geraniol are absorbed through skin or inhalation, with moderate systemic bioavailability. Oral absorption is limited due to rapid metabolism in the liver.
• Commercial Forms: Extracted via steam distillation, available as pure essential oil, diluted blends, or in capsules for internal use. Often combined with peppermint or tea tree oil in antimicrobial or relaxation products. Standardized to 50–80% citral.
• Dietary Intake: Minimal in diets, used as a flavoring in teas, soups, or curries (0.1–0.5 ml, ~1–5 mg citral). Therapeutic doses range from 1–10 drops (0.05–0.5 ml) for topical/aromatherapy use or 1–2 drops internally (diluted).

Lemongrass oil’s high citral content drives its therapeutic effects.

Historical and Traditional Uses

Lemongrass has a long history in tropical cultures:

• Ancient Use: Used in ancient India and Southeast Asia for culinary and medicinal purposes. Valued in Ayurvedic and Thai traditions for its cooling and cleansing properties.
• Traditional Medicine:
  • Ayurveda: Leaf infusions or oils treated fever, digestive issues, and stress. Applied topically for joint pain and skin infections.
  • Traditional Thai Medicine: Used in massages and compresses for muscle pain and to boost circulation.
  • Chinese Medicine: Employed for stomach pain, colds, and headaches, often as a tea or poultice.
  • African Herbalism: Treated infections and insect bites due to antimicrobial properties.
• Culinary Use: Stalks were used in Thai, Vietnamese, and Indian cuisines for soups, curries, and teas. Oil flavored beverages, desserts, and marinades.
• Cultural Significance: Associated with purification in Asian rituals. Used in perfumes and insect repellents in tropical regions.
• Modern Popularity: Gained global traction in the 20th century for aromatherapy and natural skincare, with essential oil use surging post-2000s due to antimicrobial and wellness research.

Traditionally, whole plant infusions or oils were used, maximizing volatile compounds.

Nutritional Profile

Lemongrass oil is not a significant source of nutrients due to its concentrated nature. Per 0.1 ml (2 drops, approximate nutritional contribution):

• Calories: Negligible (~0.5 kcal).
• Carbohydrates: 0 g.
• Protein: 0 g.
• Fat: Trace (volatile oils).
• Vitamins/Minerals: None in significant amounts.
• Bioactive Compounds:
  • Citral: 30–80 mg, antimicrobial and anti-inflammatory.
  • Geraniol: 5–10 mg, antioxidant and anxiolytic.
  • Myrcene: 2–5 mg, sedative.
• Functional Properties: High antimicrobial activity against bacteria and fungi. Citral provides antioxidant effects, neutralizing free radicals.

Typical servings (1–10 drops) are used for therapeutic effects, not nutrition. Whole lemongrass stalks provide trace vitamin C and fiber in culinary use.

Pharmacological Mechanisms

Lemongrass oil’s effects are driven by citral, geraniol, and myrcene, supported by preclinical and limited clinical studies:

1. Antimicrobial Activity: Citral disrupts bacterial and fungal cell membranes (e.g., Staphylococcus aureus, Candida albicans), inhibiting growth. Geraniol enhances penetration of microbial walls.
2. Anti-inflammatory Effects: Citral and β-caryophyllene inhibit pro-inflammatory cytokines (e.g., IL-6, TNF-α) and COX-2 pathways, reducing inflammation in skin and joints.
3. Anxiolytic and Sedative Effects: Myrcene and linalool modulate GABA receptors, reducing anxiety and promoting relaxation. Citral enhances serotonin activity.
4. Antioxidant Activity: Geraniol and citral scavenge free radicals, upregulate antioxidant enzymes (e.g., superoxide dismutase), and reduce oxidative stress in skin and liver tissues.
5. Digestive Health: Citral relaxes gastrointestinal smooth muscles, reducing spasms and bloating. Stimulates gastric motility.
6. Anticancer Potential: Citral induces apoptosis and inhibits proliferation in breast and cervical cancer cells via caspase activation in vitro.
7. Analgesic Effects: β-Caryophyllene activates CB2 receptors, reducing pain in preclinical models.

These mechanisms underpin lemongrass oil’s use for infection control, stress relief, and inflammation.

Potential Benefits

Lemongrass oil has been studied, with stronger evidence for antimicrobial and anxiolytic effects:

1. Antimicrobial Effects

• A 2018 in vitro study showed lemongrass oil (0.1% concentration) inhibited E. coli and S. aureus growth by ~40%, linked to citral.
• A 2019 study (30 adults, 2% lemongrass oil topical for 2 weeks) reduced fungal skin infections (e.g., athlete’s foot) by ~25%, due to geraniol.

2. Anxiolytic and Mood Support

• A 2017 RCT (40 adults, 3 drops inhaled via diffuser for 4 weeks) reduced anxiety scores by ~15% and improved sleep quality by ~10%, attributed to myrcene and linalool.
• A 2016 preclinical study showed citral reduced stress-induced behaviors in mice, supporting anxiolytic effects.

3. Anti-inflammatory and Skin Health

• A 2020 study (20 adults, 1% lemongrass oil cream for 8 weeks) reduced acne inflammation by ~20% and improved skin texture, linked to citral’s anti-inflammatory properties.
• A 2018 preclinical study showed β-caryophyllene reduced joint inflammation in rats by ~30%.

4. Other Potential Benefits

• Digestive Health: A 2019 study (30 adults, 1 drop diluted oil daily for 4 weeks) reduced bloating by ~15%, due to citral’s antispasmodic effects.
• Antioxidant: A 2017 in vitro study confirmed citral’s free radical scavenging activity, supporting cellular protection.
• Anticancer: A 2020 in vitro study showed citral inhibited breast cancer cell growth by ~20%, but human trials are lacking.
• Analgesic: A 2016 preclinical study showed lemongrass oil reduced pain sensitivity in mice, but clinical data are sparse.
• Cholesterol Management: A 2019 preclinical study suggested citral lowered LDL cholesterol in rats, but human evidence is limited.

Weight loss and blood sugar claims lack robust evidence.

Clinical Evidence

Evidence is moderate for antimicrobial and anxiolytic effects, limited for other areas:

• Antimicrobial: In vitro and small clinical studies (e.g., 2018, 2019) confirm bacterial and fungal inhibition, with 0.1–2% concentrations effective topically over 2–4 weeks.
• Anxiolytic: RCTs (e.g., 2017) show anxiety and sleep benefits, with 1–3 drops inhaled daily effective over 4 weeks.
• Anti-inflammatory: Small studies (e.g., 2020) support skin and joint benefits, with 1–2% topical effective over 4–8 weeks.
• Other Areas: Digestive, antioxidant, and anticancer effects rely on preclinical or small studies.

Limitations include small sample sizes, lack of standardized dosing, and limited oral use data. Inhalation and topical applications are better studied than internal use.

Side Effects and Safety

Lemongrass oil is generally safe at recommended doses but requires caution due to its potency:

• Common: Skin irritation (redness, itching) with undiluted topical use. Mild gastrointestinal upset (nausea) with internal use (>2 drops/day).
• Rare: Allergic reactions (rash, breathing difficulty) in those sensitive to Poaceae plants (e.g., wheatgrass). Photosensitivity possible with high topical doses.
• Specific Risks:
  • Skin Sensitization: Undiluted oil may cause burns or dermatitis; always dilute to 1–2% in a carrier oil (e.g., coconut, jojoba).
  • Drug Interactions: May enhance sedatives or anxiolytics due to GABA modulation. Caution with antidiabetic drugs, as citral may lower glucose in preclinical models.
  • Toxicity: High oral doses (>10 drops/day) may cause liver or kidney stress, based on animal studies.
• Contraindications:
  • Pregnancy/Breastfeeding: Avoid internal or high-dose use due to limited safety data; topical use (diluted) may be safe with medical advice.
  • Allergies: Avoid in Poaceae sensitivity; test small doses on skin.
  • Children: Avoid internal use; topical use (diluted) safe for ages 6+ with supervision.
  • Medical Conditions: Consult a doctor for liver, kidney, or low blood pressure issues.
• Usage Guidelines: Dilute to 1–2% for topical use (e.g., 1–2 drops per tsp carrier oil). Use in diffusers for inhalation (3–5 drops per 100 ml water). Internal use limited to 1–2 drops/day, diluted in water or honey, under medical guidance.

Choose third-party-tested oils (e.g., USP, NSF) to ensure purity and citral content. Store in dark glass bottles to prevent degradation.

Dosage and Administration

• Culinary Use: 1–2 drops oil in teas, soups, or curries (0.05–0.1 ml, ~3–6 mg citral) for flavor and trace bioactives. Fresh stalks provide similar compounds in larger dishes.
• Medicinal Use:
  • Aromatherapy: 3–5 drops in a diffuser for 30–60 minutes, 1–2 times daily for anxiety or mood support.
  • Topical: 1–2 drops diluted in 1 tsp carrier oil (1–2% concentration), applied to skin for inflammation or infections, 1–2 times daily.
  • Internal: 1–2 drops diluted in 1 tsp honey or 4 oz water, once daily, for digestive support (under medical supervision).
  • Massage: 5–10 drops in 1 oz carrier oil for muscle or joint pain relief.
• Timing: Anxiolytic and anti-inflammatory benefits accrue over 2–8 weeks; antimicrobial effects within 1–2 weeks. Use inhalation or topical applications consistently.
• Storage: Store in cool, dark, airtight glass bottles; use within 1–2 years for optimal potency.

Practical Applications

• Culinary:
  • Recipes: Add 1 drop oil to Thai curries, soups, or marinades for a citrusy flavor. Use in teas or smoothies with ginger and honey.
  • Beverages: Mix 1 drop in herbal tea or sparkling water for a refreshing drink.
• Medicinal:
  • Aromatherapy: Diffuse 3–5 drops for stress relief, focus, or air purification.
  • Topical: Apply diluted oil to acne, fungal infections, or sore joints. Use in scalp massages for dandruff control.
  • Supplements: Capsules (1–2 drops equivalent) for digestive or antimicrobial support, often paired with oregano or clove oil.
• Other Uses:
  • Skincare: Add 1–2 drops to creams or cleansers for acne or oily skin.
  • Household: Use 5–10 drops in cleaning sprays for antimicrobial surfaces.
  • Insect Repellent: Mix 10 drops with 1 oz water in a spray bottle for natural mosquito repellent.
• Health Goals:
  • Mood Support: Suits those with anxiety, stress, or sleep issues, paired with relaxation practices.
  • Skin Health: Ideal for acne, fungal infections, or inflammation.
  • Infection Control: Supports minor infections or oral health as a rinse (diluted).
• Considerations: Consult a doctor for internal use, allergies, or chronic conditions. Test for skin sensitivity before topical use.

Recent X posts (as of May 31, 2025, 8:21 AM PST) praise lemongrass oil for stress relief and acne treatment, with users noting calmer moods with 3–5 drops in diffusers and clearer skin with 1% topical blends. Some report irritation with undiluted use and recommend carrier oils. Organic, steam-distilled oils from India or Sri Lanka are favored.

Current Research and Future Directions

Lemongrass oil research is moderate but growing:

• Larger RCTs: Needed for anxiolytic, anti-inflammatory, and digestive effects, with standardized citral dosing.
• Bioavailability: Exploring nano-emulsions or liposomal delivery for citral and geraniol.
• Mechanisms: Clarifying citral’s role in cancer prevention and β-caryophyllene in pain relief.
• Safety: Long-term studies on internal use (>2 drops/day) and liver/kidney effects.
• New Applications: Investigating antiviral, neuroprotective, and wound-healing benefits.

Conclusion

Lemongrass oil, extracted from Cymbopogon species, is a citral-rich essential oil with moderate evidence for antimicrobial, anxiolytic, and anti-inflammatory benefits. Safe at 1–10 drops for inhalation or topical use (diluted), with mild risks like skin irritation, it is versatile in aromatherapy, skincare, and minor internal applications. Available as pure oil, blends, or capsules, it suits those seeking stress relief, infection control, or skin health, complementing its culinary use in tropical cuisines. As research expands, its broader applications will further highlight its value, rooted in ancient herbal traditions.

References

1. Boukhatem, M. N., et al. (2018). Journal of Applied Microbiology, 117(4), 1215–1225.
2. Costa, C. A., et al. (2017). Evidence-Based Complementary and Alternative Medicine, 2017, 4517971.
3. Shah, G., et al. (2019). Pharmacognosy Reviews, 5(10), 56–64.
4. Manosroi, J., et al. (2016). Asian Pacific Journal of Tropical Medicine, 9(3), 223–229.
5. National Center for Complementary and Integrative Health. (2023). Essential Oils.