Plan B One-Step Side Effects

Generic name: levonorgestrel

Medically reviewed by Drugs.com. Last updated on Feb 4, 2024.

Note: This document contains side effect information about levonorgestrel. Some dosage forms listed on this page may not apply to the brand name Plan B One-Step.

Applies to levonorgestrel: oral tablet. Other dosage forms:

• intrauterine insert extended release

Serious side effects of Plan B One-Step

Along with its needed effects, levonorgestrel (the active ingredient contained in Plan B One-Step) 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:

More common

• Heavy or light menstrual bleeding

Incidence not known

• Absent missed or irregular menstrual periods
• cramps
• irregular menstruation
• pain
• pain in the pelvis
• stopping of menstrual bleeding

Other side effects of Plan B One-Step

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:

More common

• Abdominal or stomach pain
• dizziness
• headache
• nausea
• tenderness of the breasts
• unusual tiredness or weakness
• vomiting

Less common

• Diarrhea

For Healthcare Professionals

Applies to levonorgestrel: intrauterine device, oral tablet, subcutaneous implant.

General

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]

Genitourinary

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

Frequency not reported: Breast enlargement, vaginal candidiasis, changes in cervical erosion, changes in cervical secretion, ectopic pregnancy

Postmarketing reports: Oligomenorrhea, irregular menstruation^[Ref]

Gastrointestinal

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]

Other

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]

Nervous system

Very common (10% or more): Headache (up to 16.8%), dizziness (11.2%)

Common (1% to 10%): Migraine

Postmarketing reports: Stroke, syncope, IUS insertion related vasovagal reaction or seizure^[Ref]

Psychiatric

Common (1% to 10%): Depression/depressed mood, mood changes, mood swings, decreased libido, nervousness

Frequency not reported: Changes in libido^[Ref]

Dermatologic

Very common (10% or more): Acne/seborrhea (15%)

Common (1% to 10%): Alopecia, hirsutism

Uncommon (0.1% to 1%): Pruritus, eczema, pigmentation changes/hyperpigmentation

Rare (less than 0.1%): Rash, urticaria

Frequency not reported: Chloasma, melasma

Postmarketing reports: Angioedema^[Ref]

Cardiovascular

Postmarketing reports: Increased blood pressure, arterial/venous thrombotic events, pulmonary emboli, deep vein thrombosis, stroke^[Ref]

Musculoskeletal

Common (1% to 10%): Back pain^[Ref]

Oncologic

Frequency not reported: Benign/malignant liver tumors

Postmarketing reports: Breast cancer^[Ref]

Ocular

Frequency not reported: Contact lens intolerance^[Ref]

Metabolic

Frequency not reported: Diabetes mellitus^[Ref]

Hypersensitivity

Frequency not reported: Allergic reaction

Postmarketing reports: Hypersensitivity reactions^[Ref]

Frequently asked questions

• Can Plan B make your period late or cause bleeding?
• Can you drink alcohol after taking Plan B?
• How effective is Plan B and how late can you take it?
• What's the weight limit for Plan B?
• How many times can you take Plan B?
• Mirena, Kyleena, Skyla & Liletta - What's the difference?

Further information

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.

Medical Disclaimer