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Research seeds: Calendula

In this article, we discuss the “The effect of Calendula officinalis versus metronidazole on bacterial vaginosis in women: A double-blind randomized controlled trial

Research seeds Calendula

Plant name and species

Calendula (Calendula officinalis)

Aim of study

Bacterial vaginosis is a common condition among people of reproductive age. This study compared a cream based on a calendula extract with metronidazole.

Study method

40 participants were randomly assigned to the calendula group, and the other 40 were assigned to the metronidazole group. Subjects were diagnosed with bacterial vaginosis if they had at least 3 of the 4 Amsel groups. Participants used their respective creams for 1 week intravaginally and symptoms were re-assessed 1 week after treatment completion. 

Herbal preparation: Methanol extract of C. officinalis was added to a base cream made of cetostearyl alcohol, petroleum jelly, glycerin, mineral oil, preservative, and antioxidant. 

Sample size: 80 women

Results of study

Prior to treatment, most women in both groups had symptoms such as dysuria (the most common symptom), vaginal burning, itching, discharge and odour. The group who were given calendula cream had much more prevalent symptoms of itching compared to the metronidazole group prior to treatment (22.5% vs 2.5%), but showed no other significant difference with regards to other symptoms. 

One week after intervention, both groups were free of symptoms, and no women suffered any side effects from either calendula or metronidazole.


Other studies have shown that calendula is effective against both gram-positive and gram-negative strains of bacteria. It has also been shown to have antifungal activity and was as effective as clotrimazole in women with candida albicans infection. Methanol extracts were shown to have stronger antibacterial activity than ethanol extracts, with minimal side effects and irritation on the skin.


Calendula is a safe and effective treatment for bacterial vaginosis and has no side effects. It was equally effective as metronidazole and could be recommended to people who are uncomfortable with the potential side effects of conventional pharmaceuticals.

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