Secnidazole (Solosec) for BV

Author: Jessica Lloyd
Senior Vulvovaginal Specialist Naturopath | BHSc(N) | ISSVD, ISSWSH, BSSM, ATMS

Last reviewed: July 30, 2026

A scientific review was conducted on secnidazole (also known as Solosec), an antibiotic used to treat bacterial vaginosis. Conclusion? It has the same success rate as metronidazole.

Understanding the research

Secnidazole has been in six clinical trials with 1,528 participants included.¹

Key findings of the review

Two grams of secnidazole improved the clinical cure of BV whether women had three or fewer, or four or more, flare-ups in the past year.
Clearing the BV-associated bacteria on testing (microbiological cure) reached significance in those with three or fewer flare-ups per year, but not in those with four or more.
Two grams of secnidazole was significantly more effective than 1g.
The cure rate of 2g secnidazole was equal to metronidazole (500mg twice daily for five days), secnidazole with metronidazole, a 2g single dose of metronidazole and 2g secnidazole with vaginal ornidazole.
Two grams of secnidazole was better than placebo.

What is secnidazole?

Secnidazole is an antibiotic structurally similar to other antibiotics commonly used to treat BV, such as metronidazole. Secnidazole is effective against many anaerobic gram-positive and gram-negative micro-organisms, including those that cause BV and various parasites.

Secnidazole is absorbed quickly after oral administration with a longer half-life than other drugs in its class (17–29 hours),² used in a single dose of one or two grams. The single dose makes it attractive for both patients and practitioners.

Resistance is reported to be rare. This drug is offered in a pill/tablet or in granules to be sprinkled on food. In the United States, secnidazole (Solosec) is approved as a single oral dose for BV, and since 2021 it is also approved to treat trichomoniasis.³

Microbes secnidazole is effective against

Bacteroides fragilis
Trichomonas vaginalis
Entamoeba histolytica
Giardia lamblia

Side-effects of secnidazole

In clinical trials, secnidazole appears to be well-tolerated overall, with most adverse events being related to the digestive tract.

Nausea
Vomiting
Loss of appetite
Digestive tract pain
Metallic taste
Swollen tongue
Headaches
Dizziness
Abnormalities in leucocyte counts
Increase in blood urea nitrogen
Yeast infection

Frequently asked questions

Is secnidazole as effective as metronidazole for BV?

In a systematic review of six trials, a single 2g dose of secnidazole cleared BV at a rate equal to metronidazole taken as 500mg twice daily for five days, and equal to a single 2g dose of metronidazole.¹

How do you take secnidazole?

It is taken as a single oral dose of 2g, either as a tablet or as granules sprinkled onto soft food such as yoghurt or apple sauce. The single dose is one of its main attractions for both patients and practitioners.²

Does secnidazole treat anything besides BV?

Yes. It is active against several other organisms, including Trichomonas vaginalis, and in the United States it is also approved to treat trichomoniasis.³

This article is general information and not a substitute for personalised medical advice. Antibiotics for BV should be prescribed and supervised by an experienced practitioner.