Can you take Plan B on Nexplanon? What you need to know

October 7, 2025 •

4 min read

With a greater than 99% efficacy rate, Nexplanon is one of the most effective forms of birth control available. Given its high reliability, the question often arises: Can you take Plan B on Nexplanon? The short answer is yes, it's generally safe, but typically unnecessary unless there's a specific concern about the implant's effectiveness.

Quick Summary

Taking Plan B while on Nexplanon is safe and does not cause a negative interaction. However, it is usually not needed due to the implant's high effectiveness. Exceptions include the first week after insertion or suspected implant failure. Consulting a healthcare provider for guidance is always recommended.

Key Points

Generally Unnecessary: Taking Plan B is typically not needed if your Nexplanon implant is in place and working correctly, as it is over 99% effective.
No Negative Interaction: There is no harmful interaction between the hormones in Plan B and Nexplanon, so taking them together is safe.
High-Dose Hormone: Plan B is a high-dose hormonal medication for one-time use, while Nexplanon provides a continuous, low dose for long-term prevention.
Seek Guidance After Recent Insertion: If unprotected sex occurred within the first seven days of a Nexplanon insertion (and not during the first five days of your period), taking Plan B may be recommended.
Consult for Suspected Issues: If you have any concerns about your implant's location or effectiveness, contact your healthcare provider immediately.
Emergency Backup: Plan B serves as an emergency backup, whereas Nexplanon is a primary contraceptive designed for consistent, long-term protection.
Watch for Interactions: Be aware that certain medications, like the antibiotic rifampin, can reduce Nexplanon's effectiveness, potentially necessitating emergency contraception.

Is it safe to take Plan B while on Nexplanon?

Yes, it is safe to take Plan B while on Nexplanon. Plan B, which contains a high dose of the progestin levonorgestrel, does not interact negatively with the etonogestrel released by the Nexplanon implant. In fact, doctors sometimes prescribe a temporary course of birth control pills, which contain similar hormones to Plan B, to help manage irregular bleeding patterns common with the implant. Therefore, combining the two medications is not harmful and will not reduce the effectiveness of your Nexplanon implant.

When might it be necessary to take Plan B on Nexplanon?

While Nexplanon offers continuous, highly effective protection, there are rare circumstances where a healthcare provider might recommend taking emergency contraception like Plan B:

During the first week after insertion: If the implant was not inserted during the first five days of your menstrual period, you need to use a backup method of contraception, like condoms, for the first seven days. If unprotected intercourse occurs within this initial week, Plan B may be advised.
Suspected implant malfunction: In the rare event you or your healthcare provider are concerned that the implant has failed or is no longer properly in place, taking Plan B could be a temporary measure. Signs of potential failure include not being able to feel the implant under your skin.
Taking interacting medications: Certain medications, most notably the antibiotic rifampin, can lower the effectiveness of hormonal birth control. If you are prescribed such a medication, you may be advised to use an additional, non-hormonal contraceptive or emergency contraception as a backup.

Why is Plan B typically unnecessary with Nexplanon?

Nexplanon is a long-acting reversible contraceptive (LARC) with an exceptionally high efficacy rate. It continuously releases a small, steady dose of the progestin etonogestrel, which prevents pregnancy in several ways:

Inhibiting ovulation: The primary mechanism of action is preventing the release of an egg from the ovary.
Thickening cervical mucus: This makes it difficult for sperm to pass through the cervix and reach an egg.
Thinning the uterine lining: This makes it harder for a fertilized egg to implant.

Because it works consistently and automatically, there is no chance of user error, such as forgetting a pill. The implant is designed to be a highly reliable, set-and-forget contraceptive for up to three years, making additional emergency contraception redundant under normal circumstances.

Comparison: Nexplanon vs. Plan B

How to proceed if you have concerns

If you have concerns about the reliability of your Nexplanon or have had unprotected sex in the first week after insertion, it's best to consult a healthcare provider. They can help you determine the appropriate next steps. If emergency contraception is deemed necessary, remember these key points:

Consider the timing: For maximum effectiveness, Plan B should be taken as soon as possible, ideally within 72 hours of unprotected sex.
Review medication interactions: Discuss any other medications you are taking with your doctor or pharmacist to ensure they don't interfere with your birth control.
Check the implant's position: Periodically check to make sure you can still feel the implant under your skin. If you can't, contact your provider immediately.

Conclusion

For anyone with a properly functioning Nexplanon implant, taking emergency contraception like Plan B is almost never necessary due to the implant's superior, long-term effectiveness. However, in specific situations, such as during the initial week after insertion or if the implant's integrity is in question, a healthcare professional might advise using Plan B for added peace of mind. The good news is that the two medications are safe to use together and do not cause a negative drug interaction. The best course of action for any concerns regarding your birth control is to speak with a healthcare provider who can offer personalized guidance and confirm your ongoing protection.

Disclaimer: This article provides general information and is not a substitute for professional medical advice. Always consult with a qualified healthcare provider for specific medical guidance.

Frequently Asked Questions

No, taking Plan B will not make your Nexplanon implant less effective. The hormones in Plan B do not interfere with the etonogestrel released by Nexplanon.

The '7-day rule' applies if Nexplanon is inserted more than five days after the start of your period. You must use a backup contraceptive method, like condoms, for the first seven days to ensure protection.

Plan B is most effective when taken as soon as possible after unprotected sex, ideally within 72 hours. However, if your Nexplanon is properly in place, it is likely unnecessary.

Yes, but it's crucial to consult a healthcare provider or pharmacist, as certain medications (like the antibiotic rifampin) can affect Nexplanon's efficacy. In such cases, Plan B might be a recommended backup.

Since both contain progestins, you might experience temporary side effects like nausea, headaches, dizziness, or irregular bleeding, which can sometimes occur with hormonal contraceptives.

You should contact your healthcare provider if you can no longer feel the implant under your skin or if you experience unusual symptoms. In very rare cases, the implant can migrate or be improperly inserted.

If your anxiety persists, speak with your healthcare provider. They can confirm the implant's placement and effectiveness and may recommend a temporary measure like Plan B or discuss more effective emergency contraception options, such as a copper IUD.