What is the appropriate use and dosage of Norgestrel, a synthetic progestogen, for a female of reproductive age seeking contraception or experiencing menstrual disorders, considering her medical history and potential risks?

Norgestrel for Contraception: Appropriate Use and Dosing

Norgestrel is available as a progestin-only pill (POP) at 0.075 mg daily (Opill, now FDA-approved for over-the-counter use) or in combination with ethinyl estradiol for contraception, with the progestin-only formulation being particularly suitable for women who cannot tolerate estrogen-containing preparations. 1

Dosing Regimens

Progestin-Only Norgestrel (Opill)

• Take 0.075 mg (one tablet) at the same time every single day without breaks, even during menstruation or breakthrough bleeding 1
• Timing is critical: Must be taken within 3 hours of the usual daily time to maintain contraceptive efficacy 1
• Backup contraception required for 2 days (48 hours) if:
  • Starting the first pack 1
  • A tablet is taken more than 3 hours late 1
  • A tablet is missed on one or more days 1
  • Vomiting or severe diarrhea occurs within 4 hours of taking a tablet 1

Combined Norgestrel-Ethinyl Estradiol

• When used in combination formulations, norgestrel has demonstrated excellent efficacy with proper adherence 2
• Combined formulations require blood pressure measurement before initiation 3

Contraceptive Efficacy

The progestin-only norgestrel formulation is highly effective when taken correctly, with approximately 98 out of 100 sexually active women not becoming pregnant within one year of perfect use 1. Historical studies show:

• Failure rate of 2.1% within first 12 cycles and 3.6% within first 30 cycles with 75 mcg daily dosing 4
• Zero pregnancies in studies of combined norgestrel formulations with perfect adherence 5, 2

Mechanism of Action

Norgestrel prevents pregnancy through multiple mechanisms 4:

• Primary mechanism: Thickening cervical mucus to block sperm penetration 1
• Secondary mechanisms: May prevent ovulation and impair luteal function 4

Absolute Contraindications

Do not use norgestrel if the patient has 1:

• Current or history of breast cancer (progestins can stimulate hormone-sensitive tumors)
• Known or suspected pregnancy
• Current use of another hormonal contraceptive method (pill, ring, patch, implant, injection, or IUD)
• Allergy to norgestrel or FD&C Yellow No. 5 (tartrazine)

Conditions Requiring Medical Consultation Before Use

Consult a physician before starting norgestrel if 1:

• Unexplained vaginal bleeding between periods (requires evaluation to rule out underlying pathology)
• Liver tumors or liver disease
• Current or history of any cancer (some cancers are hormone-sensitive)

Special Populations

Women with Hypertension

• Progestin-only pills like norgestrel are generally preferred over combined oral contraceptives for women with hypertension 3
• The U.S. Medical Eligibility Criteria generally supports use of POPs in women with controlled hypertension (Category 1-2) 3
• Blood pressure monitoring is not required before initiating progestin-only norgestrel, unlike combined hormonal contraceptives 3

Breastfeeding Women

• Norgestrel is safe and effective during breastfeeding 1
• Small amounts pass into breast milk but no adverse effects on infant health or breastfeeding performance have been documented 1

Women with Hereditary Angioedema

• Progestin-only contraceptives are generally well-tolerated in women with hereditary angioedema C1-inhibitor deficiency, unlike estrogen-containing contraceptives which increase attack frequency in 60-80% of users 3
• Normethyltestosterone derivatives (which include norgestrel) at low doses are considered mild androgens and are tolerated by approximately two-thirds of patients with this condition 3

Expected Menstrual Changes

Irregular bleeding is the most common side effect 1, 4:

• Approximately one-fifth of cycles may be shorter than 17 days 4
• About 68% of cycles remain within 28 ± 5 days 6
• Breakthrough bleeding and spotting are common, especially in early months 4
• Continue taking the pill daily even during irregular bleeding 1

Additional Side Effects

Less common side effects include 1:

• Headaches
• Dizziness
• Nausea
• Increased appetite
• Abdominal pain, cramps, or bloating

Critical Counseling Points

Adherence Strategies

Implement specific reminder systems 1:

• Pair pill-taking with a daily routine task
• Keep the pack visible in the same location
• Set smartphone alarms
• Place reminders on bathroom mirrors or other visible locations

What Norgestrel Does NOT Do

• Does not protect against HIV/AIDS or sexually transmitted infections - barrier methods (condoms) must be used for STI protection 1
• Is not emergency contraception - will not prevent pregnancy if taken after unprotected intercourse 1

Return to Fertility

• Fertility returns promptly upon discontinuation with no delay in ability to conceive 1, 4

Ongoing Healthcare Needs

Continue routine preventive care while using norgestrel 1:

• Regular cervical cancer screening (Pap smears) as recommended
• Regular breast cancer screening (mammography) as age-appropriate
• STI screening if at risk (many STIs including HIV are asymptomatic)

Comparative Effectiveness

Among contraceptive methods, progestin-only pills have 4-7 pregnancies per 100 women in one year with typical use, requiring daily adherence 1. This is less effective than long-acting reversible contraceptives (implants, IUDs) which have <1 pregnancy per 100 women annually, but more effective than barrier methods alone (>13 pregnancies per 100 women annually) 1.

Common Pitfalls to Avoid

• Missing the 3-hour window: Even small delays beyond 3 hours from usual dosing time require backup contraception for 48 hours 1
• Taking breaks between packs: All 28 tablets contain active hormone; start the next pack immediately after finishing the previous one 1
• Stopping during irregular bleeding: Breakthrough bleeding does not indicate method failure; continue daily dosing 1
• Assuming STI protection: Norgestrel provides no protection against infections 1