Quick Summary

Lemon Myrtle (Backhousia citriodora) is a plant primarily known for its essential oil, which contains bioactive compounds such as citral. Research on its efficacy and safety is still pending conclusive human clinical evidence. Essential oils from lemon myrtle demonstrate potential antimicrobial and insecticidal properties in vitro and in animal studies; however, evidence from human clinical trials is currently lacking.

What Is It?

Lemon Myrtle is an Australian native tree whose leaves are widely used to extract essential oil rich in citral and other monoterpenes. The oil is valued for its citrus aroma and is used in flavoring, aromatherapy, and traditional remedies.

Traditional Uses

Traditionally, lemon myrtle leaves and oils have been used by Indigenous Australian peoples for their aromatic and potential preservative qualities. Its applications have included use as an antimicrobial agent and insect repellent, though these uses are based largely on cultural practices rather than formal scientific validation.

Active Compounds

The primary active compounds in lemon myrtle essential oil include:

  • Citral: a major component responsible for aroma and biological activity.
  • Monoterpenes: a class of compounds that contribute to various bioactivities, including antimicrobial effects.
  • Phenolic compounds: present in extracts with possible preservative or antimicrobial properties.

Potential Benefits with Evidence Levels

  • Potential antimicrobial effects

    Evidence level: Preclinical (in vitro)

    Essential oils from lemon myrtle contain phenolic compounds that show promising antimicrobial activity in laboratory studies.
  • Acaricidal and insecticidal potential

    Evidence level: Preclinical (in vitro and laboratory animal models)

    Lemon myrtle essential oil, rich in citral, has exhibited insecticidal and acaricidal activity relevant for pest control in companion animals. However, reliable field efficacy and clinical safety data are not yet established.

Side Effects

Specific adverse effects related to lemon myrtle in humans are not well documented due to a lack of clinical data. Some monoterpenes found in lemon myrtle essential oil have shown toxic effects such as embryotoxicity, neurotoxicity, allergenicity, and genotoxicity in preclinical studies. This suggests a need for caution, especially when used in concentrated forms without medical supervision.

Drug Interactions

Currently, there are no documented drug interactions involving lemon myrtle based on available research data.

Who Should Avoid It

While no formal contraindications are reported, caution is advised for:

  • Pregnant or breastfeeding individuals, due to potential embryotoxic effects of some monoterpenes found in lemon myrtle essential oil.
  • Individuals with sensitivities to essential oils or monoterpenes.
  • Those with underlying health conditions until safety is better established.

Evidence Limitations

Most evidence regarding lemon myrtle’s effects comes from preclinical studies, including in vitro and animal research. There are no published human randomized controlled trials or meta-analyses confirming its efficacy or safety. Toxicological data primarily derive from related monoterpenes rather than direct human exposure studies, limiting the clinical relevance and generalizability of the findings.

References

Last Reviewed

April 2024

Disclaimer: This information is for educational purposes only and is not intended as medical advice. Consult a healthcare professional before using lemon myrtle or any herbal supplement, especially if you are pregnant, breastfeeding, have pre-existing health conditions, or are taking medications.