PillSeek

Professional Information — Loestrin Fe 1/20 28 Day

Full FDA prescribing details for healthcare professionals.

Last updated · May 16, 2026Source: DailyMed ↗
On this page
Highlights of Prescribing InformationRevised: Feb 20, 2025

Loestrin ® 21 Day

(norethindrone acetate and ethinyl estradiol tablets, USP)

Loestrin ® 1/20

(Each light yellow tablet contains 1 mg norethindrone acetate, USP and 20 mcg ethinyl estradiol, USP.)

Loestrin ® 1.5/30

(Each pink tablet contains 1.5 mg norethindrone acetate, USP and 30 mcg ethinyl estradiol, USP.)

Loestrin ® Fe 28 Day

(norethindrone acetate and ethinyl estradiol tablets, USP and ferrous fumarate tablets*)

*Ferrous fumarate tablets are not USP for dissolution and assay

Loestrin ® Fe 1/20

(Each light yellow tablet contains 1 mg norethindrone acetate, USP and 20 mcg ethinyl estradiol, USP. Each brown tablet contains 75 mg ferrous fumarate, USP.)

Loestrin ® Fe 1.5/30

(Each pink tablet contains 1.5 mg norethindrone acetate, USP and 30 mcg ethinyl estradiol, USP. Each brown tablet contains 75 mg ferrous fumarate, USP.)

Rx only

Indications and Usage

Loestrin 21 and Loestrin Fe 28 are indicated for the prevention of pregnancy in women who elect to use oral contraceptives as a method of contraception.

Oral contraceptives are highly effective. Table I lists the typical accidental pregnancy rates for users of combination oral contraceptives and other methods of contraception. The efficacy of these contraceptive methods, except sterilization, depends upon the reliability with which they are used. Correct and consistent use of methods can result in lower failure rates.

TABLE I: LOWEST EXPECTED AND TYPICAL FAILURE RATES DURING THE FIRST YEAR OF CONTINUOUS USE OF A METHOD

% Of Women Experiencing an Unintended Pregnancy in the First Year of Continuous Use

Method

Lowest
Expected*

Typical**

(No contraception)

(85)

(85)

Oral contraceptives
combined
progestin only

0.1
0.5

3
N/A***
N/A***

Diaphragm with spermicidal cream or jelly

6

20

Spermicides alone (foam, creams, gels, vaginal suppositories, and vaginal film)

6

26

Vaginal Sponge
nulliparous
parous

9
20

20
40

Implant

0.05

0.05

Injection: depot medroxyprogesterone acetate

0.3

0.3

IUD
progesterone T
copper T 380A
LNg 20

1.5
0.6
0.1

2
0.8
0.1

Condom without spermicides
female
male

5
3

21
14

Cervical Cap with spermicidal cream or jelly
nulliparous
parous

9
26

20
40

Periodic abstinence (all methods)

1 to 9

25

Withdrawal

4

19

Female sterilization

0.5

0.5

Male sterilization

0.10

0.15

Adapted from RA Hatcher et al, Reference 7.

* The authors' best guess of the percentage of women expected to experience an accidental pregnancy among

couples who initiate a method (not necessarily for the first time) and who use it consistently and correctly during the first year if they do not stop for any other reason.

** This term represents “typical” couples who initiate use of a method (not necessarily for the first time),

who experience an accidental pregnancy during the first year if they do not stop use for any other reason.

*** N/A-Data not available.


Dosage and Administration

The tablet dispenser has been designed to make oral contraceptive dosing as easy and as convenient as possible. The tablets are arranged in either three or four rows of seven tablets each, with the days of the week appearing on the tablet dispenser above the first row of tablets.

Note: Each tablet dispenser has been preprinted with the days of the week, starting with Sunday, to facilitate a Sunday-Start regimen. Six different day label strips have been provided with the Detailed Patient & Brief Summary Patient Package Insert in order to accommodate a Day-1 Start regimen. If the patient is using the Day-1 Start regimen, she should place the self-adhesive day label strip that corresponds to her starting day over the preprinted days.

Important: The patient should be instructed to use an additional method of protection until after the first week of administration in the initial cycle when utilizing the Sunday-Start regimen.

The possibility of ovulation and conception prior to initiation of use should be considered.

Dosage and Administration for 21-Day Dosage Regimen

To achieve maximum contraceptive effectiveness, Loestrin 21 must be taken exactly as directed and at intervals not exceeding 24 hours. Loestrin 21 provides the patient with a convenient tablet schedule of “3 weeks on - 1 week off”. Two dosage regimens are described, one of which may be more convenient or suitable than the other for an individual patient. For the initial cycle of therapy, the patient begins her tablets according to the Day-1 Start or Sunday-Start regimen. With either regimen, the patient takes one tablet daily for 21 consecutive days followed by one week of no tablets.

A. Sunday-Start Regimen: The patient begins taking tablets from the top row on the first Sunday after menstrual flow begins. When menstrual flow begins on Sunday, the first tablet is taken on the same day. The last tablet in the dispenser will then be taken on a Saturday, followed by no tablets for a week (7 days). For all subsequent cycles, the patient then begins a new 21-tablet regimen on the eighth day, Sunday, after taking her last tablet. Following this regimen, of 21 days on - 7 days off, the patient will start all subsequent cycles on a Sunday.

B. Day-1 Regimen: The first day of menstrual flow is Day 1. The patient places the self-adhesive day label strip that corresponds to her starting day over the preprinted days on the tablet dispenser. She starts taking one tablet daily, beginning with the first tablet in the top row. The patient completes her 21-tablet regimen when she has taken the last tablet in the tablet dispenser. She will then take no tablets for a week (7 days). For all subsequent cycles, the patient begins a new 21-tablet regimen on the eighth day after taking her last tablet, again starting with the first tablet in the top row after placing the appropriate day label strip over the preprinted days on the tablet dispenser. Following this regimen of 21 days on - 7 days off, the patient will start all subsequent cycles on the same day of the week as the first course. Likewise, the interval of no tablets will always start on the same day of the week.

Tablets should be taken regularly with a meal or at bedtime. It should be stressed that efficacy of medication depends on strict adherence to the dosage schedule.

Special Notes on Administration

Menstruation usually begins two or three days, but may begin as late as the fourth or fifth day, after discontinuing medication. If spotting occurs while on the usual regimen of one tablet daily, the patient should continue medication without interruption.

If the patient forgets to take one or more tablets, the following is suggested:

One tablet is missed

  • take tablet as soon as remembered
  • take next tablet at the regular time

Two consecutive tablets are missed (week 1 or week 2)

  • take two tablets as soon as remembered
  • take two tablets the next day
  • use another birth control method for seven days following the missed tablets

Two consecutive tablets are missed (week 3)

Sunday-Start Regimen:

  • take one tablet daily until Sunday
  • discard remaining tablets
  • start new pack of tablets immediately (Sunday)
  • use another birth control method for seven days following the missed tablets

Day-1 Start Regimen:

  • discard remaining tablets
  • start new pack of tablets that same day
  • use another birth control method for seven days following the missed tablets

Three (or more) consecutive tablets are missed

Sunday-Start Regimen:

  • take one tablet daily until Sunday
  • discard remaining tablets
  • start new pack of tablets immediately (Sunday)
  • use another birth control method for seven days following the missed tablets

Day-1 Start Regimen:

  • discard remaining tablets
  • start new pack of tablets that same day
  • use another birth control method for seven days following the missed tablets

The possibility of ovulation occurring increases with each successive day that scheduled tablets are missed. While there is little likelihood of ovulation occurring if only one tablet is missed, the possibility of spotting or bleeding is increased. This is particularly likely to occur if two or more consecutive tablets are missed.

In the rare case of bleeding which resembles menstruation, the patient should be advised to discontinue medication and then begin taking tablets from a new tablet dispenser on the next Sunday or the first day (Day 1), depending on her regimen. Persistent bleeding which is not controlled by this method indicates the need for reexamination of the patient, at which time nonfunctional causes should be considered.

Dosage and Administration for 28-Day Dosage Regimen

To achieve maximum contraceptive effectiveness, Loestrin Fe should be taken exactly as directed and at intervals not exceeding 24 hours.

Loestrin Fe provides a continuous administration regimen consisting of 21 light yellow or pink tablets of Loestrin and 7 brown non-hormone containing tablets of ferrous fumarate. The ferrous fumarate tablets are present to facilitate ease of drug administration via a 28-day regimen and do not serve any therapeutic purpose. There is no need for the patient to count days between cycles because there are no “off-tablet days.”

A. Sunday-Start Regimen: The patient begins taking the first light yellow or pink tablet from the top row of the dispenser (labeled Sunday) on the first Sunday after menstrual flow begins. When the menstrual flow begins on Sunday, the first light yellow or pink tablet is taken on the same day. The patient takes one light yellow or pink tablet daily for 21 days. The last light yellow or pink tablet in the dispenser will be taken on a Saturday. Upon completion of all 21 light yellow or pink tablets, and without interruption, the patient takes one brown tablet daily for 7 days. Upon completion of this first course of tablets, the patient begins a second course of 28-day tablets, without interruption, the next day (Sunday), starting with the Sunday light yellow or pink tablet in the top row. Adhering to this regimen of one light yellow or pink tablet daily for 21 days, followed without interruption by one brown tablet daily for seven days, the patient will start all subsequent cycles on a Sunday.

B. Day-1 Start Regimen: The first day of menstrual flow is Day 1. The patient places the self-adhesive day label strip that corresponds to her starting day over the preprinted days on the tablet dispenser. She starts taking one light yellow or pink tablet daily, beginning with the first light yellow or pink tablet in the top row. After the last light yellow or pink tablet (at the end of the third row) has been taken, the patient will then take the brown tablets for a week (7 days). For all subsequent cycles, the patient begins a new 28 tablet regimen on the eighth day after taking her last light yellow or pink tablet, again starting with the first tablet in the top row after placing the appropriate day label strip over the preprinted days on the tablet dispenser. Following this regimen of 21 light yellow or pink tablets and 7 brown tablets, the patient will start all subsequent cycles on the same day of the week as the first course.

Tablets should be taken regularly with a meal or at bedtime. It should be stressed that efficacy of medication depends on strict adherence to the dosage schedule.

Special Notes on Administration

Menstruation usually begins two or three days, but may begin as late as the fourth or fifth day, after the brown tablets have been started. In any event, the next course of tablets should be started without interruption. If spotting occurs while the patient is taking light yellow or pink tablets, continue medication without interruption.

If the patient forgets to take one or more light yellow or pink tablets, the following is suggested:

One tablet is missed

  • take tablet as soon as remembered
  • take next tablet at the regular time

Two consecutive tablets are missed (week 1 or week 2)

  • take two tablets as soon as remembered
  • take two tablets the next day
  • use another birth control method for seven days following the missed tablets

Two consecutive tablets are missed (week 3)

Sunday-Start Regimen:

  • take one tablet daily until Sunday
  • discard remaining tablets
  • start new pack of tablets immediately (Sunday)
  • use another birth control method for seven days following the missed tablets

Day-1 Start Regimen:

  • discard remaining tablets
  • start new pack of tablets that same day
  • use another birth control method for seven days following the missed tablets

Three (or more) consecutive tablets are missed

Sunday-Start Regimen:

  • take one tablet daily until Sunday
  • discard remaining tablets
  • start new pack of tablets immediately (Sunday)
  • use another birth control method for seven days following the missed tablets

Day-1 Start Regimen:

  • discard remaining tablets
  • start new pack of tablets that same day
  • use another birth control method for seven days following the missed tablets

The possibility of ovulation occurring increases with each successive day that scheduled light yellow or pink tablets are missed. While there is little likelihood of ovulation occurring if only one light yellow or pink tablet is missed, the possibility of spotting or bleeding is increased. This is particularly likely to occur if two or more consecutive light yellow or pink tablets are missed.

If the patient forgets to take any of the seven brown tablets in week four, those brown tablets that were missed are discarded and one brown tablet is taken each day until the pack is empty. A back-up birth control method is not required during this time. A new pack of tablets should be started no later than the eighth day after the last light yellow or pink tablet was taken.

In the rare case of bleeding which resembles menstruation, the patient should be advised to discontinue medication and then begin taking tablets from a new tablet dispenser on the next Sunday or the first day (Day-1), depending on her regimen. Persistent bleeding which is not controlled by this method indicates the need for reexamination of the patient, at which time nonfunctional causes should be considered.

Use of Oral Contraceptives in the Event of a Missed Menstrual Period

  1. If the patient has not adhered to the prescribed dosage regimen, the possibility of pregnancy should be considered after the first missed period and oral contraceptives should be withheld until pregnancy has been ruled out.
  2. If the patient has adhered to the prescribed regimen and misses two consecutive periods, pregnancy should be ruled out before continuing the contraceptive regimen.

After several months on treatment, bleeding may be reduced to a point of virtual absence. This reduced flow may occur as a result of medication, in which event it is not indicative of pregnancy.

Contraindications

Oral contraceptives are contraindicated in women who currently have the following conditions:

  • Thrombophlebitis or thromboembolic disorders
  • A past history of deep vein thrombophlebitis or thromboembolic disorders
  • Cerebral vascular or coronary artery disease
  • Current diagnosis of, or history of, breast cancer, which may be hormone sensitive
  • Carcinoma of the endometrium or other known or suspected estrogen-dependent neoplasia
  • Undiagnosed abnormal genital bleeding
  • Cholestatic jaundice of pregnancy or jaundice with prior pill use
  • Hepatic adenomas or carcinomas
  • Are receiving Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to the potential for ALT elevations (see Warnings, RISK OF LIVER ENZYME ELEVATIONS WITH CONCOMITANT HEPATITIS C TREATMENT ).

Adverse Reactions

An increased risk of the following serious adverse reactions has been associated with the use of oral contraceptives (see WARNINGS section):

  • Thrombophlebitis
  • Arterial thromboembolism
  • Pulmonary embolism
  • Myocardial infarction
  • Cerebral hemorrhage
  • Cerebral thrombosis
  • Hypertension
  • Gallbladder disease
  • Hepatic adenomas or benign liver tumors

Post Marketing Experience

Five studies that compared breast cancer risk between ever-users (current or past use) of COCs and never-users of COCs reported no association between ever use of COCs and breast cancer risk, with effect estimates ranging from 0.90 - 1.12 (Figure 1) (70-74).

Three studies compared breast cancer risk between current or recent COC users (<6 months since last use) and never users of COCs (Figure 1) (70, 73, 75). One of these studies reported no association between breast cancer risk and COC use. The other two studies found an increased relative risk of 1.19 - 1.33 with current or recent use. Both of these studies found an increased risk of breast cancer with current use of longer duration, with relative risks ranging from 1.03 with less than one year of COC use to approximately 1.4 with more than 8-10 years of COC use.

FIGURE 1: RELEVANT STUDIES OF RISK OF BREAST CANCER WITH  COMBINED ORAL CONTRACEPTIVES

Figure from prescribing information

RR = relative risk; OR = odds ratio; HR = hazard ratio. “ever COC” are females with current or past COC use; “never COC use” are females that never used COCs.

There is evidence of an association between the following conditions and the use of oral contraceptives, although additional confirmatory studies are needed:

  • Mesenteric thrombosis
  • Retinal thrombosis

The following adverse reactions have been reported in patients receiving oral contraceptives and are believed to be drug-related:

  • Nausea
  • Vomiting
  • Gastrointestinal symptoms (such as abdominal cramps and bloating)
  • Breakthrough bleeding
  • Spotting
  • Change in menstrual flow
  • Amenorrhea
  • Temporary infertility after discontinuation of treatment
  • Edema
  • Melasma which may persist
  • Breast changes: tenderness, enlargement, secretion
  • Change in weight (increase or decrease)
  • Change in cervical erosion and secretion
  • Diminution in lactation when given immediately postpartum
  • Cholestatic jaundice
  • Migraine
  • Rash (allergic)
  • Depression
  • Reduced tolerance to carbohydrates
  • Vaginal candidiasis
  • Change in corneal curvature (steepening)
  • Intolerance to contact lenses

The following adverse reactions have been reported in users of oral contraceptives and the association has been neither confirmed nor refuted:

  • Pre-menstrual syndrome
  • Cataracts
  • Changes in appetite
  • Cystitis-like syndrome
  • Headache
  • Nervousness
  • Dizziness
  • Hirsutism
  • Loss of scalp hair
  • Erythema multiforme
  • Erythema nodosum
  • Hemorrhagic eruption
  • Vaginitis
  • Porphyria
  • Impaired renal function
  • Hemolytic uremic syndrome
  • Budd-Chiari syndrome
  • Acne
  • Changes in libido
  • Colitis
figure 1

Overdosage

Serious ill effects have not been reported following acute ingestion of large doses of oral contraceptives by young children. Overdosage may cause nausea, and withdrawal bleeding may occur in females.

Description

Loestrin® 21 and Loestrin® Fe 28 are progestogen-estrogen combinations.

Loestrin® Fe 1/20 and 1.5/30: Each provides a continuous dosage regimen consisting of 21 oral contraceptive tablets and seven ferrous fumarate tablets. The ferrous fumarate tablets are present to facilitate ease of drug administration via a 28-day regimen, are non-hormonal, and do not serve any therapeutic purpose.

Each light yellow tablet contains norethindrone acetate, USP (17α-ethinyl-19-nortestosterone acetate), 1 mg; ethinyl estradiol, USP (17α-ethinyl-1,3,5(10)-estratriene-3, 17β-diol), 20 mcg. Each light yellow tablet contains the following inactive ingredients: acacia, compressible sugar, D&C yellow no. 10 aluminum lake, lactose monohydrate, magnesium stearate and pregelatinized corn starch.

Each pink tablet contains norethindrone acetate, USP (17α-ethinyl-19-nortestosterone acetate), 1.5 mg; ethinyl estradiol, USP (17α-ethinyl-1,3,5(10)-estratriene-3, 17β-diol), 30 mcg. Each pink tablet contains the following inactive ingredients: acacia, compressible sugar, FD&C red no. 40 aluminum lake HT, lactose monohydrate, magnesium stearate and pregelatinized corn starch.

Each brown tablet contains the following ingredients: crospovidone, ferrous fumarate, hydrogenated vegetable oil, NF Type I and microcrystalline cellulose.

Norethindrone Acetate, USP

Figure from prescribing information

C22H28O3                              M.W. 340.46

Ethinyl Estradiol, USP

Figure from prescribing information

C20H24O2                           M.W. 296.40

Norethindrone Acetate, USP Structural Formula Ethinyl Estradiol, USP Structural Formula

Clinical Pharmacology

Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increase the difficulty of sperm entry into the uterus) and the endometrium (which reduce the likelihood of implantation).

Pharmacokinetics

The pharmacokinetics of Loestrin have not been characterized; however, the following pharmacokinetic information regarding norethindrone acetate and ethinyl estradiol is taken from the literature.

Absorption

Norethindrone acetate appears to be completely and rapidly deacetylated to norethindrone after oral administration, since the disposition of norethindrone acetate is indistinguishable from that of orally administered norethindrone (1). Norethindrone acetate and ethinyl estradiol are subject to first-pass metabolism after oral dosing, resulting in an absolute bioavailability of approximately 64% for norethindrone and 43% for ethinyl estradiol (1-3).

Distribution

Volume of distribution of norethindrone and ethinyl estradiol ranges from 2 to 4 L/kg (1 to 3). Plasma protein binding of both steroids is extensive (greater than 95%); norethindrone binds to both albumin and sex hormone binding globulin, whereas ethinyl estradiol binds only to albumin (4).

Metabolism

Norethindrone undergoes extensive biotransformation, primarily via reduction, followed by sulfate and glucuronide conjugation. The majority of metabolites in the circulation are sulfates, with glucuronides accounting for most of the urinary metabolites (5). A small amount of norethindrone acetate is metabolically converted to ethinyl estradiol. Ethinyl estradiol is also extensively metabolized, both by oxidation and by conjugation with sulfate and glucuronide. Sulfates are the major circulating conjugates of ethinyl estradiol and glucuronides predominate in urine.

The primary oxidative metabolite is 2-hydroxy ethinyl estradiol, formed by the CYP3A4 isoform of cytochrome P450. Part of the first-pass metabolism of ethinyl estradiol is believed to occur in gastrointestinal mucosa. Ethinyl estradiol may undergo enterohepatic circulation (6).

Excretion

Norethindrone and ethinyl estradiol are excreted in both urine and feces, primarily as metabolites (5, 6). Plasma clearance values for norethindrone and ethinyl estradiol are similar (approximately 0.4 L/hr/kg) (1-3).

Special Population

Race:

The effect of race on the disposition of Loestrin has not been evaluated.

Renal Insufficiency

The effect of renal disease on the disposition of Loestrin has not been evaluated. In premenopausal women with chronic renal failure undergoing peritoneal dialysis who received multiple doses of an oral contraceptive containing ethinyl estradiol and norethindrone, plasma ethinyl estradiol concentrations were higher and norethindrone concentrations were unchanged compared to concentrations in premenopausal women with normal renal function.

Hepatic Insufficiency

The effect of hepatic disease on the disposition of Loestrin has not been evaluated. However, ethinyl estradiol and norethindrone may be poorly metabolized in patients with impaired liver function.

Drug-Drug Interactions

Numerous drug-drug interactions have been reported for oral contraceptives. A summary of these is found under PRECAUTIONS, Drug Interactions.

How Supplied / Storage and Handling

Loestrin 1/20 (21 Tablets) (norethindrone acetate 1 mg and ethinyl estradiol 20 mcg tablets, USP) are packaged in cartons of five blister cards. Each card contains 21 light yellow, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 977 on the other side. (NDC 51285-131-97).

Loestrin Fe 1/20 (28 Tablets) (norethindrone acetate 1 mg and ethinyl estradiol 20 mcg tablets, USP, and ferrous fumarate tablets) are packaged in cartons of five blister cards. Each card contains 21 light yellow, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 977 on the other side and 7 brown, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 247 on the other side. Each brown tablet contains 75 mg ferrous fumarate. The ferrous fumarate tablets are present to facilitate ease of drug administration via a 28-day regimen, are non-hormonal, and do not serve any therapeutic purpose. (NDC 51285-125-70).

Loestrin 1.5/30 (21 Tablets) (norethindrone acetate 1.5 mg and ethinyl estradiol 30 mcg tablets, USP) are packaged in cartons of five blister cards. Each card contains 21 pink, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 978 on the other side. (NDC 51285-127-97).

Loestrin Fe 1.5/30 (28 Tablets) (norethindrone acetate 1.5 mg and ethinyl estradiol 30 mcg tablets, USP, and ferrous fumarate tablets) are packaged in cartons of five blister cards. Each card contains 21 pink, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 978 on the other side and 7 brown, round, flat-faced, beveled-edge, unscored tablets debossed with stylized b on one side and 247 on the other side. Each brown tablet contains 75 mg ferrous fumarate. The ferrous fumarate tablets are present to facilitate ease of drug administration via a 28-day regimen, are non-hormonal, and do not serve any therapeutic purpose. (NDC 51285-128-70).

Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].

Sources

RxCUI: 1358770

Last fetched: May 16, 2026

Source: DailyMed ↗

⚠️ Disclaimer

This information is for educational purposes only and is not medical advice. Always consult your doctor, pharmacist, or other licensed healthcare professional before starting, stopping, or changing any medicine. Read full medical disclaimer.