What can a male patient do to prevent or manage bacterial vaginosis?

Patient Education: Bacterial Vaginosis and Male Partners

What You Need to Know

As a male partner, you do not need treatment for bacterial vaginosis (BV) in most circumstances, as treating male partners has traditionally not been shown to prevent recurrence in female partners. 1 However, emerging evidence suggests this recommendation may need reconsideration in specific situations.

Understanding BV and Your Role

BV Is Not a Classic STD

• BV is not considered a sexually transmitted infection in the traditional sense, though it is associated with sexual activity. 1, 2
• Women who have never been sexually active rarely develop BV, but the condition results from disruption of normal vaginal bacteria (protective Lactobacillus species) rather than transmission of a specific pathogen. 1, 2
• Multiple sexual partners increase BV risk in women, but the exact mechanism remains unclear. 1, 2

Traditional Guidance vs. New Evidence

• CDC guidelines from 1993-2002 consistently stated that treating male partners does not prevent BV recurrence in female partners. 1
• However, a groundbreaking 2025 study challenges this long-standing recommendation: when male partners received combined oral metronidazole (400mg twice daily) AND topical 2% clindamycin cream (applied to penile skin twice daily) for 7 days, female partners had significantly lower BV recurrence rates (35% vs 63% recurrence at 12 weeks). 3
• This represents an absolute risk reduction of 2.6 recurrences per person-year. 3

What This Means for You

When Partner Treatment May Be Considered

If your female partner experiences recurrent BV (multiple episodes), discuss partner treatment with her healthcare provider, as the most recent high-quality evidence suggests combined oral and topical treatment for male partners reduces recurrence. 3

Important Caveats About the Evidence

• Earlier studies using only oral metronidazone showed no benefit, but these trials had significant methodological flaws including poor adherence monitoring and suboptimal treatment regimens. 4, 5
• The 2025 study used a combination approach (both oral medication and topical cream applied to penile skin), which appears critical for success. 3
• A 2021 study using only oral metronidazole found no overall benefit, but women whose partners actually adhered to the medication had lower failure rates, suggesting adherence is crucial. 4

Practical Steps You Can Take

If Treatment Is Recommended

• Take the full 7-day course of both oral metronidazole and topical clindamycin cream exactly as prescribed—adherence appears critical for success. 3, 4
• Apply the topical cream to penile skin as directed, not just the glans. 3
• Avoid alcohol during treatment and for 24 hours after completing metronidazole to prevent nausea and other side effects. 1
• Expect possible side effects including nausea, headache, and metallic taste. 3

During Your Partner's Treatment

• Refrain from unprotected sexual intercourse for at least 14 days while both partners complete treatment. 4
• Consider using condoms during this period to prevent potential reintroduction of BV-associated bacteria. 4

Supporting Your Partner

• Understand that BV has a high recurrence rate (50-80% within one year) even with proper treatment, which is not due to treatment failure but rather difficulty in reestablishing normal vaginal bacteria. 6, 2, 7
• Up to 50% of women with BV have no symptoms, so absence of symptoms doesn't mean the condition has resolved. 1, 6, 2
• Encourage your partner to complete her full treatment course and follow up with her healthcare provider. 6, 8

Key Pitfalls to Avoid

• Don't assume you need treatment automatically—the decision should be made by your partner's healthcare provider, particularly if she has recurrent (not first-time) BV. 3
• Don't use only oral medication if treatment is prescribed—the evidence supporting partner treatment used both oral and topical therapy together. 3
• Don't stop treatment early even if symptoms resolve in your partner—incomplete treatment may contribute to recurrence. 7, 4
• Don't assume BV is "just an infection"—it's associated with serious complications in women including increased STI risk and pregnancy complications, making proper management important. 6, 2