Norethindrone acetate and ethinyl estradiol tablets side effects

What Is Lo Loestrin Fe?

Lo Loestrin Fe (norethindrone acetate, ethinyl estradiol, and ferrous fumarate) is a 28-day oral tablet birth control regimen. It works to prevent ovulation and causes changes to the cervical mucus and endometrial lining, blocking sperm penetration and reducing the chance of implantation.

Drug Facts

Generic Name: Norethindrone Acetate, Ethinyl Estradiol, and Ferrous Fumarate

Brand Name(s): Lo Loestrin Fe

Administration Route(s): Oral

Drug Availability: Prescription

Therapeutic Classification: Combination oral contraceptive

Available Generically: No

Controlled Substance: N/A

Active Ingredient: Norethindrone Acetate, Ethinyl Estradiol, and Ferrous Fumarate

Dosage Form(s): Tablet

What Is Lo Loestrin Fe Used For?

Lo Loestrin Fe is a form of birth control that comes in a blister pack of 28 tablets. The tablets within the blister pack contain different combinations of ethinyl estradiol (a female estrogen hormone), norethindrone acetate (a progestin female hormone), and an iron supplement.

Each blister pack contains the following tablets in the following order:

  • 24 blue, round (active) tablets imprinted with “WC” on one side and “421” on the other and each containing 1 milligram of norethindrone acetate and 10 micrograms of ethinyl estradiol.
  • Two white, hexagonal (active) tablets imprinted with “WC” on one side and “422” on the other and each containing 10 micrograms of ethinyl estradiol.
  • Two brown, round (nonhormonal placebo) tablets imprinted with “WC” on one side and “624” on the other and each containing 75 milligrams of ferrous fumarate. The ferrous fumarate tablets are iron tablets and do not serve any therapeutic purpose regarding birth control.

The combination of norethindrone acetate, ethinyl estradiol, and ferrous fumarate can also be used to treat moderate acne vulgaris, a common form of acne that mainly develops on the face and upper trunk.

Verywell / Zoe Hansen

How to Take Lo Loestrin Fe

To be most effective at preventing pregnancy, Lo Loestrin Fe must be taken exactly as directed. It is best to take one tablet by mouth at the same time every day. Take the tablet in the order directed on the blister pack. Do not skip tablets or take tablets at intervals exceeding 24 hours unless directed otherwise.

You can take Lo Loestrin Fe with or without food.  If you miss a pill or if you vomit or have diarrhea within three to four hours after taking a blue or white (active) pill, please follow the following instructions:

  • Missed one blue (active) pill: Take it as soon as you remember and then take the next tablet at your regular time (may take two tablets in one day); backup contraception is not necessary if this happens.
  • Missed two consecutive blue (active) pills in weeks one or two of blister pack: Take two tablets on the day remembered and two tablets the next day, then one tablet per day until the pack is finished; nonhormonal backup contraception is recommended for the next seven days.
  • Missed two consecutive blue or white (active) pills in weeks three or four of blister pack: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is recommended for the first seven days of starting the new pack.
  • Missed three consecutive blue or white (active) pills at any time: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is recommended for the first seven days of starting the new pack.
  • Missed any brown "reminder" pills in week four: Discard missed tablets; continue taking remaining tablets in pack; backup contraception is not necessary if this happens.

Do not eat grapefruit or drink grapefruit juice while you are using Lo Loestrin Fe. Grapefruit can increase the concentration of Lo Loestrin Fe in your body. The more Lo Loestrin Fe in your body, the greater likelihood that you will have unwanted side effects.

Storage

Store this Lo Loestrin Fe in a closed container at room temperature (68 degrees to 77 degrees Fahrenheit), away from heat, moisture, and direct light. Keep all medicine out of the reach of children. Never share your medicine with anyone.

Off-Label Uses

Norethindrone acetate, ethinyl estradiol, and ferrous fumarate can also be used off-label for health conditions that it is has shown to be beneficial in treating. However, these uses are not approved by the Food and Drug Administration (FDA)

This medication is sometimes recommended off-label for:

  • Polycystic ovary syndrome (PCOS, a hormonal imbalance causing infrequent periods and excess androgen hormones)
  • Amenorrhea (absence of menstruation)
  • Endometriosis (often painful condition in which the tissue from the uterus grows outside the uterus)

How Long Does Lo Loestrin Fe Take to Work?

If you start your pack on the first day of your period, you do not need to use backup contraception, like condoms. However, if you start taking the pill on any day other than the first day of your period, you should use backup contraception for the first seven days.

What Are the Side Effects of Lo Loestrin Fe?


This is not a complete list of side effects and others may occur. A medical professional can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at www.fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects of Lo Loestrin Fe include:

  • Mood changes, depression, and anxiety
  • Headaches
  • Nausea and vomiting
  • Breast tenderness
  • Weight gain
  • Period (menstrual) changes such as painful periods, vaginal spotting or light bleeding, itching, or discharge
  • Acne
  • Abdominal pain

You may have spotting or light vaginal bleeding or feel nauseated during the first few months of taking Lo Loestrin Fe. Try not to stop taking the pill, even if you have these mild side effects. If these side effects become too bothersome or do not go away, ask your provider about another method of birth control that may work better for you.

Severe Side Effects

Severe side effects of Lo Loestrin Fe and their symptoms can include:

  • Allergic reactions: Itching or hives, swelling in your face or hands, swelling, or tingling in your mouth or throat, chest tightness, trouble breathing
  • Breast lumps, tenderness, pain, swelling, or discharge
  • Chest pain that may spread, trouble breathing, unusual sweating, or fainting
  • Dark urine or pale stools, loss of appetite, yellow skin or whites of the eyes
  • Heavy vaginal bleeding, irregular or missed menstrual period
  • Numbness or weakness in your arm or leg, or on one side of your body, pain in your lower leg (calf), sudden or severe headache, or problems with vision, speech, or walking
  • Sudden and severe stomach pain, nausea, vomiting, light-headedness
  • Vision loss, double or blurred vision

You should not smoke while taking Lo Loestrin Fe, as this can increase your risk for serious cardiovascular events. Please report and seek emergency medical care for signs or symptoms of serious cardiovascular events, such as myocardial infarction (heart attack), stroke, venous thrombosis, pulmonary embolism, and retinal vein thrombosis.

Always notify your primary care provider if you develop any serious side effects to Lo Loestrin Fe.

This birth control may also cause skin discoloration. Use sunscreen when you are outdoors. Avoid sunlamps and tanning beds.

Long-Term Side Effects

Lo Loestrin Fe may cause the following problems:

  • Increased risk of heart attack, stroke, or blood clots
  • Increased risk of breast, endometrial, ovarian, or cervical cancer
  • Liver problems (including liver tumor or cancer)
  • High blood pressure
  • Gallbladder disease
  • Eye or vision problems

Report Side Effects

Lo Loestrin Fe may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

(800) 332-1088

Dosage: How Much of Lo Loestrin Fe Should I Take?

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Your doctor may ask you to begin your dose on the first day of your menstrual period (called Day 1 Start), on the fifth day (called Day 5 start), or on the first Sunday after your menstrual period starts (called Sunday Start). When you begin on a certain day it is important that you follow that schedule, even if you miss a dose. Do not change your schedule on your own. If the schedule that you use is not convenient, check with your doctor about changing it. For the Day 5 start and Sunday start, you need to use another form of birth control (eg, condom, diaphragm, spermicide) for the first 7 days.

  • For oral dosage forms (chewable tablets or tablets):
    • For contraception (to prevent pregnancy):
      • Adults and teenagers—
        • FEMCON® Fe: One white tablet (active) taken at the same time each day for 21 consecutive days followed by one brown (inert) tablet daily for 7 days per menstrual cycle.
        • Lo Loestrin® Fe: One blue (active) taken at the same time each day for 24 consecutive days followed by one white tablet for 2 consecutive days, followed by one brown (inert) tablet daily for 2 consecutive days.
        • Minastrin® 24 Fe: One white tablet (active) taken at the same time each day for 21 consecutive days followed by one brown (inert) tablet daily for 7 days per menstrual cycle.
        • Norminest® Fe: One blue tablet (active) taken at the same time each day for 21 consecutive days followed by one brown (inert) tablet daily for 7 days per menstrual cycle.
        • Norquest® Fe: One yellow-green tablet (active) taken at the same time each day for 21 consecutive days followed by one brown (inert) tablet daily for 7 days per menstrual cycle.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

This medicine has specific instructions on what to do if you miss a dose. You should always use a second form of birth control for the next seven days after you miss a dose. The missed dose instructions are as follows:

  • Missed one blue (active) pill: Take as soon as you remember and then take the next tablet at regular time (may take two tablets in one day); backup contraception is not necessary if this happens.
  • Missed two consecutive blue (active) pills in weeks one or two of blister pack: Take two tablets on the day remembered and two tablets the next day, then one tablet per day until the pack is finished; nonhormonal backup contraception is required for the next seven days.
  • Missed two consecutive blue or white (active) pills in weeks three or four of blister pack: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is required for the first seven days of starting the new pack.
  • Missed three consecutive blue or white (active) pills at any time: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is required for the first seven days of starting the new pack.
  • Missed any brown "reminder" pills in week four: Discard missed tablets; continue taking remaining tablets in pack; backup contraception is not required if this happens.

Light bleeding or spotting can occur if you do not take a pill on schedule. Unfortunately, the more pills you miss, the more likely you are to have bleeding. If you miss a pill or change your schedule, you may not have a period that month. Tell your healthcare provider if you miss your period two months in a row, because you may be pregnant.

Overdose: What Happens If I Take Too Much Lo Loestrin Fe?

There are no reports of severe effects from overdosing on oral birth control pills. However, taking too much Lo Loestrin Fe can cause nausea and withdrawal bleeding.

What Happens If I Overdose on Lo Loestrin Fe?

If you think you or someone else may have overdosed on Lo Loestrin Fe, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking Lo Loestrin Fe, call 911 immediately.

911

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests may also be needed to check for unwanted effects. These visits will usually be every 6 to 12 months, but some doctors require them more often.

Although you are using this medicine to prevent pregnancy, you should know that using this medicine while you are pregnant could harm the unborn baby. If you think you have become pregnant while using the medicine, tell your doctor right away.

Do not use this medicine together with medicine to treat hepatitis C virus infection, including ombitasvir/paritaprevir/ritonavir, with or without dasabuvir (Technivie®, Viekira Pak®).

Vaginal bleeding of various amounts may occur between your regular menstrual periods during the first 3 months of use. This is sometimes called spotting when slight, or breakthrough bleeding when heavier.

  • If this should occur, continue with your regular dosing schedule.
  • The bleeding usually stops within 1 week. Check with your doctor if the bleeding continues for more than 1 week.
  • If bleeding continues after you have been taking hormonal contraceptives on schedule and for more than 3 months, check with your doctor.

Check with your doctor right away if you miss a menstrual period. Missed periods may occur if you skip one or more active tablets and have not taken your pills exactly as directed. If you miss two periods in a row, talk to your doctor. You might need a pregnancy test.

If you suspect that you may be pregnant, stop using this medicine immediately and check with your doctor.

Do not use this medicine if you smoke cigarettes or if you are over 35 years old. If you smoke while using birth control pills, you increase your risk of having a heart attack, stroke, or blood clot. Your risk is even higher if you are over age 35, if you have diabetes, high blood pressure, high cholesterol, or if you are overweight. Talk with your doctor about ways to stop smoking. Keep your diabetes under control. Ask your doctor about diet and exercise to control your weight and blood cholesterol level.

Using this medicine may increase your risk of having heart attack, stroke, or blood clots. Check with your doctor right away if you have pain in the chest, groin, or legs, especially the calves, difficulty with breathing, a sudden, severe headache, slurred speech, a sudden, a sudden loss of coordination, or vision changes while using this medicine.

Check with your doctor immediately if you have trouble wearing contact lenses or if blurred vision, difficulty with reading, or any other change in vision occurs during or after treatment. Your doctor may want your eyes to be checked by an ophthalmologist (eye doctor).

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Check with your doctor before refilling an old prescription, especially after a pregnancy. You will need another physical examination and your doctor may change your prescription.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before having surgery or certain medical tests.

This medicine may cause skin discoloration. Use a sunscreen when you are outdoors. Avoid sunlamps and tanning beds.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

What Are Reasons I Shouldn’t Take Lo Loestrin Fe?

People with the following conditions should not take Lo Loestrin Fe:

  • Breast cancer or other estrogen- or progestin-sensitive cancer, current or past history
  • Cerebrovascular disease
  • Cigarette smoking and older than 35 years
  • Coronary artery disease
  • Taking hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir
  • A current or past history of deep vein thrombosis (DVT) or pulmonary embolism
  • Diabetes mellitus with vascular disease
  • Headaches with focal neurological symptoms or migraine headaches with or without aura if older than 35 years 
  • Liver disease 
  • Liver tumors, benign or malignant
  • Inherited or acquired blood clotting disorders
  • High blood pressure (uncontrolled)
  • Pregnancy
  • Thrombogenic valvular or thrombogenic rhythm diseases of the heart (e.g., subacute bacterial endocarditis with valvular disease or atrial fibrillation)
  • Uterine bleeding (undiagnosed abnormal)

What Medications Interact With Lo Loestrin Fe?

Certain antibiotics and other drugs may cause oral contraceptives to be less effective, and backup contraception may be necessary. Consult healthcare professionals prior to starting new medications.

The following list contains some drugs that tend to make birth control less effective:

  • Medicine to treat an infection, including ampicillin, Diflucan (fluconazole), Gris-PEG (griseofulvin), Sporanox (itraconazole), Nizoral (ketoconazole), Mycobutin (rifabutin), Rifadin (rifampicin), tetracycline, Vfend (voriconazole)
  • Medicine to treat human immunodeficiency virus (HIV), including Agenerase/Norvir (amprenavir/ritonavir), Anzavir-R (atazanavir/ritonavir), Durart (darunavir/ritonavir), Intelence (etravirine), Lexiva/Norvir (fosamprenavir/ritonavir), Crixivan (indinavir), Kaletra (lopinavir/ritonavir), Viracept (nelfinavir), Viramune (nevirapine), Norvir (ritonavir), Aptivus/Norvir (tipranavir/ritonavir)
  • Medicine to treat seizures, including Tegretol (carbamazepine), Felbatol (felbamate), Lamictal (lamotrigine), Trileptal (oxcarbazepine), Solfoton (phenobarbital), Dilantin (phenytoin), Banzel (rufinamide), Topamax (topiramate)

If you do not know if your current medications may interact with your birth control, talk with your healthcare provider or pharmacist.

Frequently Asked Questions

  • What is Lo Loestrin Fe used for?

    Lo Loestrin Fe is an oral form of birth control. It is used to prevent pregnancy.

  • How does Lo Loestrin Fe work?

    Lo Loestrin Fe works to prevent pregnancy primarily by preventing ovulation. It also causes changes to the cervical mucus and endometrial lining that block sperm penetration and reduce the chance of implantation

  • What should I do if I miss a dose?

    • Missed one blue (active) pill: Take one as soon as you remember and then take the next tablet at your regular time (may take two tablets in one day); backup contraception is not necessary if this happens.
    • Missed two consecutive blue (active) pills in weeks one or two of blister pack: Take two tablets on the day remembered and two tablets the next day, then one tablet per day until the pack is finished; nonhormonal backup contraception is required for the next seven days.
    • Missed two consecutive blue or white (active) pills in weeks three or four of blister pack: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is required for the first seven days of starting the new pack.
    • Missed three consecutive blue or white (active) pills at any time: Discard the remaining pills of the current pack and start a new pack the same day; nonhormonal backup contraception is required for the first seven days of starting the new pack.
    • Missed any brown "reminder" pills in week four: Discard missed tablets; continue taking remaining tablets in pack; backup contraception is not required if this happens.

How Can I Stay Healthy While Taking Lo Loestrin Fe?

It is important to know that Lo Loestrin Fe will not protect you from getting HIV or other sexually transmitted infections (STIs). Remember to practice safe sex techniques to reduce your risk of getting an STI if you are sexually active while taking Lo Loestrin Fe. 

It may take a few months for your body to adjust to taking Lo Loestrin Fe daily. If you develop any side effects that you are uncomfortable with or that can lead to life-threatening issues, please notify your healthcare provider to discuss if Lo Loestrin Fe is the right birth control for you.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare professional. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

What is the downside to estradiol norethindrone acetate tablets?

Using this medicine may increase your risk of dementia, especially in women 65 years of age and older. This medicine may increase your risk of having gallbladder disease. Check with your doctor if you start to have stomach pains, nausea, and vomiting.

What side effects does norethindrone acetate have?

Nausea, vomiting, headache, dizziness, mood swings, trouble sleeping, weight gain/loss, acne, breast swelling/tenderness, change in sexual interest, unwanted hair growth, or hair loss may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Is norethindrone ethinyl estradiol safe?

Using this medicine can increase your risk of blood clots, stroke, heart attack, or cancer of the breast, uterus, or ovaries. Ethinyl estradiol and norethindrone should not be used to prevent heart disease, stroke, or dementia.

Does norethindrone acetate and ethinyl estradiol make you gain weight?

These side effects include: Weight gain. Bloating and weight gain are common on Estrostep and other birth control pills that use norethindrone and ethinyl estradiol. This weight gain is typically caused by water retention and is most common during the first one to two months of use.