Can you have sex after taking Plan B?
Key Points
- Plan B One-Step (levonorgestrel emergency contraceptive), also known as the morning-after pill, is an oral medication used to prevent pregnancy after unprotected sex or birth control failure.
- Plan B One-Step does not offer ongoing protection, and is only meant to prevent pregnancy after a single instance of unprotected sex.
- If you are sexually active and want to prevent pregnancy, it is essential to use a reliable form of birth control consistently.
Plan B One-Step contains a progestin called levonorgestrel, and is taken within 3 days of unprotected sex to prevent pregnancy. Sometimes called the morning-after pill, Plan B One-Step does not offer ongoing protection. While you can have sex after taking Plan B One-Step, it is important to use a back-up method to prevent pregnancy from occurring.
Plan B One-Step is only meant to be taken one time after having unprotected sex. It is highly effective, but even after taking it within 72 hours after unprotected sex there is still a chance you can become pregnant. Additionally, it does not continue to prevent pregnancy as it only works in the short term. This is because having sex after taking Plan B One-Step could mean sperm outlasts the effects of the medication.
Immediate vs. Ongoing Protection: Clarifying the limits of Plan B
Plan B One-Step is formulated to prevent pregnancy following a single act of unprotected sex or contraceptive failure. It does not protect you from getting pregnant if you have unprotected sex after taking the pill—each new incident requires new protection. Plan B temporarily delays ovulation, and its effect does not extend to future sexual activity. For continuous protection, regular birth control is essential.
What Back-up Birth Control Methods Can I Use After Taking Plan B One-Step?
Having unprotected sex after taking Plan B places you at risk of pregnancy, as the medication only works for the incident that prompted its use. Sperm from subsequent encounters could survive in your system beyond the pill’s effectiveness window, leading to fertilization once ovulation resumes. It's critical to use reliable contraception for any sex after taking Plan B.
Talk with your healthcare provider about the best form of birth control for you. Emergency contraceptives are not meant to be a regular birth control method. Some back-up birth control options may include:
- Condoms
- Diaphragm
- Spermicide
- Intrauterine device (IUD)
If you are sexually active, a long-term birth control option such as hormonal contraception might be a good option.
Related questions
- Can Plan B make your period late or cause bleeding?
- What are the signs that Plan B didn't work?
- Can you drink alcohol after taking Plan B?
How Does Plan B Work?
Plan B One Step contains a hormone called levonorgestrel. It works by blocking the surge of luteinizing hormone, which typically happens before ovulation occurs (when your ovary releases an egg). This delays or stops ovulation. Additionally, Plan B One-Step thickens cervical mucus, which affects how well sperm can move and reach the released eggs. These actions help prevent fertilization of an egg so that pregnancy cannot occur.
Some medications can affect how well Plan B One-Step works. Check with your healthcare provider if you are taking any other medications. If you vomit within 2 hours after taking Plan B One-Step, contact your healthcare professional to see if you need to repeat the dose.
If a fertilized egg has implanted into your womb already, Plan B One-Step will not affect the pregnancy.
What To Do After Plan B?
After using Plan B, you can continue (or start) your usual birth control method right away. For maximum protection, use condoms or an alternate backup method for at least seven days following Plan B, especially if you’re returning to oral contraceptives or starting a new method. Condoms also guard against STIs, offering dual protection.
Is Repeat Use of Plan B Harmful?
There is no official limit to how many times you can safely use Plan B—even multiple times within the same menstrual cycle if necessary. However, frequent use isn't recommended as a substitute for regular contraception due to increased risk of side effects and lower overall effectiveness. If you find yourself using emergency contraception often, consider speaking to your healthcare provider for a more reliable long-term option.
This is not all the information you need to know about Plan B One-Step (levonorgestrel emergency contraceptive) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.
References
- Centers for Disease Control and Prevention. 2024. Contraception and Birth Control Methods. Accessed 12/30/2024 at https://www.cdc.gov/contraception/about/index.html
- Foundation Consumer Healthcare. (n.d.). Frequently asked questions. Plan B One-Step. Accessed on August 9, 2025 from https://www.planbonestep.com/faqs/
- Plan B One-Step [package insert]. Updated January 2023. Foundation Consumer Healthcare LLC. Accessed 12/30/2024 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6ce6b40e-14ac-47bd-a648-ddf9e452e559
- University of California, San Francisco. n.d. Conception: How It Works. Accessed 12/30/2024 at https://crh.ucsf.edu/about-fertility/conception
Read next
Does Plan B One Step work during ovulation?
No, Plan B One Step won’t work if you have already started ovulating because it works by temporarily stopping ovulation (when your ovary releases an egg for fertilization from sperm). Continue reading
How effective is Plan B and how late can you take it?
Plan B (levonorgestrel) is estimated to be 60% to 94% effective at preventing pregnancy when taken within 3 days (72 hours) after unprotected sex. Somewhere between 0.6% to 2.6% of women who take Plan B within this time frame will still become pregnant. Continue reading
How many times can you take Plan B?
You can take Plan B (levonorgestrel) as many times as needed for emergency contraception. There is no known limit on the number of times you can safely use Plan B. Plan B can even be taken more than once in the same menstrual cycle. Continue reading
See also:
Related medical questions
- What's the weight limit for Plan B?
- Is Plan B an abortion pill?
- What are my birth control options and how effective are they?
- Mirena, Kyleena, Skyla & Liletta - What's the difference?
- What is a medical abortion and what is a morning after pill?
- Can antibiotics delay or make your period late?
- How long do antibiotics affect birth control?
- Why are my nipples sore? 7 possible causes
- What should I expect after a Mirena IUD removal?
- Do antibiotics affect the morning after pill?
- What are the side effects of IUDs?
- Birth control failure rates - the Pearl Index explained
- When do I start taking Diane pills for birth control?
- Is it normal to have discharge on Depo shot?
- Can Kyleena cause weight gain?
- After having a Kyleena insertion, how long do I have to wait to have intercourse?
- When will I get my first period after inserting the Implanon implant?
- Is this normal - spotting and stomach cramps from starting birth control pills?
- Can Kyleena cause acne?
- Twirla vs Xulane: How do they compare?
- ParaGard vs Mirena: What's the difference?
- Is it okay to take Vyvanse while on birth control?
- How do I use Opill birth control?
- Can Kyleena make your period stop?
- Opill OTC vs other birth control pills: What's the difference?
- Can you get pregnant with an IUD?
- Can I get pregnant the first time I have sex?
- Should I stop using Xulane if I get a rash?
- Can you start the Xulane patch anytime?
- How much does Opill cost?
Related support groups
- Plan B One-Step (329 questions, 2,157 members)
- Contraception (238 questions, 1,063 members)
- Emergency Contraception (286 questions, 1,188 members)
- Birth Control (467 questions, 3,681 members)