Quick Summary

Sweet Violet (Viola odorata) is a medicinal plant investigated primarily for potential effects on chronic insomnia and antiviral activity. Extracts of Viola odorata leaves showed significant antiviral effects in vitro against SARS-CoV-2. Clinical evidence from a meta-analysis suggests that Viola odorata extract may improve sleep quality and certain insomnia parameters when compared with placebo. Research is ongoing, and further pharmacological and clinical studies are needed.

What is it?

Sweet Violet (Viola odorata) is a flowering plant native to Europe and Asia, known for its fragrant purple flowers. It has a history of use in traditional herbal medicine and is now being studied scientifically for its possible health effects.

Traditional Uses

Traditionally, Sweet Violet has been used in herbal remedies to support respiratory health, reduce inflammation, and promote relaxation and sleep. It is commonly used in teas, extracts, and topical preparations.

Active Compounds

The therapeutic properties of Viola odorata are attributed to its bioactive constituents, including flavonoids, glycosides, alkaloids, and essential oils. These compounds may contribute to its antiviral and sedative effects observed in preliminary studies.

Potential Benefits with Evidence Levels

  • Improvement in chronic insomnia symptoms (Moderate evidence): A systematic review and meta-analysis of four articles including five clinical trials with 224 patients found that Viola odorata extract supplementation led to improvements in total Pittsburgh Sleep Quality Index (PSQI) scores, subjective sleep quality, sleep duration, and Insomnia Severity Index (ISI) scores compared to placebo (Huang et al., 2022).
  • Antiviral activity against SARS-CoV-2 (in vitro) (Preclinical evidence): Leaf extracts, particularly ethyl acetate fractions of Viola odorata, demonstrated significant antiviral activity in cell culture models of SARS-CoV-2, showing high inhibition rates at low concentrations (Vahekeni et al., 2025).

Side Effects

No significant adverse effects or toxicity reports specific to Viola odorata were identified in current clinical studies or reviews. However, mild adverse events have been reported in studies involving herbal remedies used for insomnia, but these were not specifically linked to Viola odorata. General caution is advised due to limited clinical safety data.

Drug Interactions

There are no documented data on drug interactions with Viola odorata available from current sources.

Who Should Avoid It

There is insufficient evidence to determine specific contraindications for Viola odorata. Due to unknown safety, it is advisable that pregnant or breastfeeding women avoid use unless under medical supervision. Those with allergies to plants in the Violaceae family should exercise caution.

Evidence Limitations

  • Most clinical evidence comes from small sample sizes and a limited number of randomized controlled trials.
  • Antiviral findings are based solely on in vitro studies with no confirmed clinical trials to date.
  • Safety, potential drug interactions, contraindications, and effects during pregnancy and breastfeeding have not been adequately studied.
  • Further large-scale, well-designed clinical trials are needed to establish efficacy and safety more conclusively.

References

Last Reviewed

June 2024

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult a healthcare professional before using any herbal products, especially if you are pregnant, breastfeeding, have existing health conditions, or are taking medications.