Is it safe to have sex during menstruation and are there specific days that are considered safer than others?

Sex During Menstruation: Safety and Timing Considerations

Sex during menstruation is medically acceptable on any day of the menstrual period, though it carries a modestly increased risk of sexually transmitted infection (STI) transmission that should be mitigated with barrier protection.

Safety Profile

STI Transmission Risk

• Sexual intercourse during menstruation is associated with increased risk of STI transmission, with studies showing a strong statistical association between menstrual sex and self-reported STD history 1
• This increased susceptibility may be explained by the sexual behavior itself and/or hampered innate immune system response during menses 2
• Consistent condom use during menstrual intercourse is recommended to reduce STI risk, including HIV transmission 1, 3

General Medical Acceptability

• Intercourse during menses is practiced by 3-30% of sexually active women and is considered an acceptable sexual behavior 2
• There is no evidence that menstrual intercourse increases risk for pelvic inflammatory disease 2
• Most women who engage in menstrual sex are in committed relationships and view it as a normal part of intimate partnership 4

Pregnancy Risk Considerations

Low but Not Zero Risk

• For women with regular cycles (26-32 days), the most fertile days are days 8-19 of the menstrual cycle 5, 6
• However, the timing of the 6-day fertile window varies greatly even among women with regular cycles 5, 6
• Women with shorter cycles (<26 days) experience earlier ovulation, with fertile periods potentially beginning as early as day 6 6

Practical Implications

• While pregnancy risk during active menstruation is generally low, it is not zero, particularly for women with:
  • Short menstrual cycles 6
  • Irregular cycle lengths 5
  • Prolonged menstrual bleeding that extends into the fertile window

Clinical Recommendations

Risk Mitigation Strategy

• Use barrier contraception (condoms) during menstrual intercourse to prevent STI transmission 1, 3
• This approach simultaneously addresses both STI risk and residual pregnancy risk
• Condom use during menses is independently associated with STI prevention as a primary motivation 3

Patient Counseling Points

• Weigh potential advantages (sexual satisfaction, relationship intimacy) against possible disadvantages (STI risk, messiness) 2
• Emphasize that no specific day during menstruation is categorically "safer" than another—the key is consistent barrier protection 1, 3
• For women trying to conceive, intercourse every 1-2 days beginning soon after menstruation ends optimizes fertility 6

Special Populations

• Women with multiple sexual partners or new partners should be particularly counseled about STI risk during menstrual sex 1
• Independent decision-making about condom use during menses is associated with STI prevention as the primary motivation 3