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Side Effects of Plan B

Plan B is a form of emergency contraception used to prevent pregnancy after unprotected sex or contraceptive failure. When you consider taking any medication, it is always important to be aware of its potential side effects. This blog will provide a comprehensive overview of Plan B and when to seek a medical professional.

How do they work?

Plan B contains levonorgestrel, a hormone found in many birth control pills but at a higher dose. It works primarily by preventing ovulation (the release of an egg from the ovary). If ovulation has already occurred, Plan B will not work. It is most effective when taken within 72 hours of unprotected sex before ovulation.

It is important to note that Emergency contraception isn't as effective as other methods of contraception and is not recommended for routine use. Also, the morning-after pill can fail even with correct use, and it offers no protection against sexually transmitted infections.

Common Side Effects

While Plan B is generally safe, it can cause side effects in some individuals. Here are the most common ones:

1. Nausea and Vomiting

  • Many women report feeling nauseous after taking Plan B. This is the most common side effect and can sometimes lead to vomiting. If vomiting occurs within two hours of taking the pill, it's important to contact a healthcare provider, as another dose may be necessary.

2. Fatigue

  • Feeling unusually tired is another frequent side effect. This fatigue typically subsides within a day or two.

3. Headache

  • Some individuals experience headaches after taking Plan B. Over-the-counter pain relief, such as ibuprofen or acetaminophen, can help manage this symptom.

4. Dizziness

  • Dizziness can occur but is usually mild and short-lived. It’s advisable to avoid activities that require full alertness, such as driving, until this symptom passes.

5. Breast Tenderness

  • Hormonal changes can lead to breast tenderness or sensitivity. This side effect usually resolves within a few days.

6. Menstrual Changes

  • Plan B can cause temporary changes in your menstrual cycle. Your next period might be earlier, later, or heavier than usual. Irregular bleeding or spotting between periods is also possible.

7. Abdominal Pain or Cramps

  • Some individuals experience abdominal pain or cramping. These symptoms are generally mild and short-term.

When to Seek Medical Attention

Most side effects of Plan B are mild and temporary. However, you should seek medical attention if you experience:

  • Bleeding or spotting that lasts longer than a week

  • Severe lower abdominal pain 3-5 weeks after taking the pill 

Plan B is an option that some people choose for emergency contraception. While it is generally safe, it can cause side effects ranging from nausea to menstrual changes. Understanding these potential side effects and knowing when to seek medical attention can help you feel more informed and prepared. If you took Plan B and you are not sure if you are pregnant, come to Pregnancy Resources of Abilene and get a free pregnancy test today. 


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