Plan B Side Effects
Generic Name: levonorgestrel
Medically reviewed by Drugs.com. Last updated on Nov 24, 2020.
Note: This document contains side effect information about levonorgestrel. Some of the dosage forms listed on this page may not apply to the brand name Plan B.
For the Consumer
Applies to levonorgestrel: oral tablet
Other dosage forms:
Side effects requiring immediate medical attention
Along with its needed effects, levonorgestrel (the active ingredient contained in Plan B) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking levonorgestrel:
- Heavy or light menstrual bleeding
Incidence not known
- Absent missed or irregular menstrual periods
- irregular menstruation
- pain in the pelvis
- stopping of menstrual bleeding
Side effects not requiring immediate medical attention
Some side effects of levonorgestrel may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Abdominal or stomach pain
- tenderness of the breasts
- unusual tiredness or weakness
For Healthcare Professionals
Applies to levonorgestrel: intrauterine device, oral tablet, subcutaneous implant
The most commonly reported adverse effects are alterations of menstrual bleeding patterns, nausea, abdominal/pelvic pain, headache/migraine, dizziness, fatigue, amenorrhea, ovarian cysts, genital discharge, acne/seborrhea, breast tenderness, and vulvovaginitis.[Ref]
Very common (10% or more): Irregular menstrual bleeding (67%), infrequent menstrual bleeding (up to 57%), ovarian cyst (31.2%), menstrual changes (up to 31.9%), decreased uterine bleeding (23.4%), prolonged menstrual bleeding (22%), vulvovaginitis (20.2%), amenorrhea (18.4%), genital discharge (up to 14.9%), heavier menstrual bleeding (13.8%),vaginal infections (13.6%), vulvovaginal infections (13.3%), lighter menstrual bleeding (12.5%), increased scheduled uterine bleeding (11.9%), breast tenderness (10.7%)
Common (1% to 10%): Dysmenorrhea, breast pain/discomfort, upper genital tract infection, genital tract bleeding, pelvic inflammatory disease, endometritis, dyspareunia, pelvic discomfort/pain, delay of menses more than 7 days, vaginal discharge, bleeding not related to menses
Uncommon (0.1% to 1%): Uterine spasm, cervicitis/Papanicolaou smear normal class II, change in vaginal secretion
Rare (less than 0.1%): Uterine perforation
Postmarketing reports: Oligomenorrhea, irregular menstruation[Ref]
Very common (10% or more): Nausea (up to 23.1%), abdominal/pelvic pain (up to 22.6%)
Common (1% to 10%): Diarrhea, vomiting
Uncommon (0.1% to 1%): Abdominal distension
Frequency not reported: Bloating, abdominal cramps[Ref]
Very common (10% or more): Fatigue (16.9%)
Common (1% to 10%): Partial/complete IUS expulsion, weight increased
Uncommon (0.1% to 1%): Edema, change in body weight
Very rare (less than 0.01%): Face edema
Frequency not reported: Decreased weight, sepsis, group A streptococcal sepsis
Postmarketing reports: IUS breakage, procedural bleeding[Ref]
Very common (10% or more): Headache (up to 16.8%), dizziness (11.2%)
Common (1% to 10%): Migraine
Common (1% to 10%): Depression/depressed mood, mood changes, mood swings, decreased libido, nervousness
Frequency not reported: Changes in libido[Ref]
Very common (10% or more): Acne/seborrhea (15%)
Rare (less than 0.1%): Rash, urticaria
Frequency not reported: Chloasma, melasma
Common (1% to 10%): Back pain[Ref]
Frequency not reported: Benign/malignant liver tumors
Frequency not reported: Contact lens intolerance[Ref]
Frequency not reported: Allergic reaction
Postmarketing reports: Hypersensitivity reactions[Ref]
1. "Product Information. Kyleena (levonorgestrel)." Bayer Pharmaceutical Inc, West Haven, CT.
2. "Product Information. Mirena (levonorgestrel)." Berlex Laboratories, Richmond, CA.
3. "Product Information. Plan B (levonorgestrel)." Women's Capital Corporation, Bellevue, WA.
4. "Product Information. Skyla (levonorgestrel)." Bayer Pharmaceutical Inc, West Haven, CT.
5. Cerner Multum, Inc. "Australian Product Information." O 0
6. "Product Information. Liletta (levonorgestrel)." Actavis Pharma, Inc., Parsippany, NJ.
7. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
Frequently asked questions
More about Plan B (levonorgestrel)
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- 1524 Reviews
- Drug class: contraceptives
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.