How long after taking a 2,000mg dose of Flagyl (metronidazole) can you have sex?

When Can You Resume Sexual Activity After Taking 2,000mg of Flagyl (Metronidazole)?

You should abstain from sexual intercourse until both you and your sex partner(s) have completed treatment and are asymptomatic—which means waiting until therapy is finished for both parties. For a single 2,000mg dose of metronidazole, this translates to waiting at least 7 days after taking the medication before resuming sexual activity. 1

Timing Based on Treatment Indication

The 2,000mg single-dose regimen is most commonly used for:

For Trichomoniasis Treatment

• Wait 7 days after taking the single dose before having sex 1
• This waiting period applies even if you become asymptomatic immediately after treatment 1
• Both you and all sexual partners must complete treatment before resuming sexual activity to prevent reinfection 1
• The CDC explicitly states: "Patients should be instructed to avoid sex until they and their sex partners are cured. In the absence of a microbiologic test of cure, this means when therapy has been completed and patient and partner(s) are asymptomatic." 1

For Bacterial Vaginosis (Alternative Regimen)

• The same 7-day abstinence period applies when the 2,000mg single dose is used for bacterial vaginosis 1
• Note that this is an alternative regimen with lower efficacy than the standard 7-day course for BV 1

Critical Considerations for Treatment Success

Partner Treatment is Essential

• All sexual partners from the past 60 days must be treated simultaneously 1
• Failure to treat partners is the most common cause of treatment failure and reinfection 1
• You should abstain from sex until all partners have also completed their treatment 1

Why the 7-Day Wait Matters

• The single 2,000mg dose achieves peak plasma concentrations of approximately 40 mcg/mL within 1-2 hours, with an elimination half-life of 8 hours 2
• However, achieving microbiologic cure requires adequate tissue penetration and time for the medication to eradicate the infection 2
• Cure rates for the single-dose regimen are approximately 90-95% for trichomoniasis 1
• Recent evidence suggests the 7-day metronidazole regimen (500mg twice daily) may be more effective than single-dose therapy, with lower failure rates 3, 4

Common Pitfalls to Avoid

• Do not resume sexual activity before 7 days, even if symptoms resolve immediately 1
• Do not have sex if your partner has not been treated, regardless of whether they have symptoms 1
• Avoid alcohol during treatment and for 24 hours after to prevent disulfiram-like reactions 1, 5
• Do not assume asymptomatic partners don't need treatment—most men with trichomoniasis are asymptomatic but still infectious 1

When Treatment May Fail

If symptoms persist or recur after the 7-day waiting period:

• Re-treatment with metronidazole 500mg twice daily for 7 days is recommended 1
• This often indicates reinfection from an untreated partner rather than treatment failure 1
• Ensure all partners were adequately treated before resuming sexual activity 1