Norgestrel - Comprehensive Research Paper

Document Version: 1.0 Last Updated: 2025-12-26 Classification: HRT Research - Female Progestins (Gonane Class - Racemic) Paper Number: 38 of 76

1. Summary

1.1 Executive Summary

Norgestrel is a racemic synthetic gonane progestin consisting of a 1:1 mixture of two stereoisomers: dextronorgestrel (inactive) and levonorgestrel (active). As such, norgestrel is exactly half as potent as its active isomer levonorgestrel. While primarily used for contraception, norgestrel has been incorporated into menopausal hormone therapy (HRT) combinations in some countries.

Key Distinguishing Features:

• Racemic mixture: Contains 50% inactive dextronorgestrel + 50% active levonorgestrel
• Half the potency of levonorgestrel: Requires double the dose for equivalent effect
• First totally synthetic progestin: Manufactured via total chemical synthesis (1963)
• OTC availability: First oral contraceptive approved for OTC sale in U.S. (Opill, 2023)
• Weak androgenic activity: Same profile as levonorgestrel but at half the potency

Historical and Current Use:

• Ovrette (0.075 mg): Original progestin-only pill (discontinued U.S. 2005)
• Opill (0.075 mg): OTC progestin-only contraceptive (FDA approved 2023)
• Cyclo-Progynova: Sequential HRT combination (estradiol valerate + norgestrel) - available internationally
• Combined oral contraceptives: Lo/Ovral, Cryselle, others (with ethinyl estradiol)

Safety Profile:

• VTE risk: Minimal (progestin-only; no significant VTE increase)
• Breast cancer: No estrogen-related increase; progestin-only considerations apply
• Androgenic effects: Present but mild at contraceptive/HRT doses
• Cardiovascular: Lower risk than combined hormonal contraceptives

Current Formulations:

| Product | Composition | Route | Use | Availability | |---

Goal Relevance:

• I want a reliable birth control option that I can buy over the counter.
• I'm looking for hormone therapy to help manage my menopause symptoms.
• I need a contraceptive that doesn't increase my risk of blood clots.
• I'm interested in a cost-effective hormone treatment for reproductive health.
• I want a birth control method that doesn't contain estrogen.
• I'm seeking a hormone therapy option that is available internationally.

------|-------------|-------|-----|--------------| | Opill | Norgestrel 0.075 mg | Oral | Contraception (OTC) | U.S. (2024) | | Cyclo-Progynova | E2V 2 mg + Norgestrel 0.5 mg | Oral | Sequential HRT | Europe, international | | Lo/Ovral | EE 30 mcg + Norgestrel 0.3 mg | Oral | Combined OC | U.S. | | Cryselle | EE 30 mcg + Norgestrel 0.3 mg | Oral | Combined OC | U.S. |

1.2 Chemical and Pharmacological Classification

Chemical Name: rac-13β-Ethyl-17α-ethynyl-17β-hydroxygon-4-en-3-one (racemic mixture) Molecular Formula: C₂₁H₂₈O₂ Molecular Weight: 312.45 g/mol CAS Number: 6533-00-2

Classification:

• Drug Class: Progestin (synthetic progesterone analogue)
• Subclass: Gonane (13-ethyl-gonane derivative)
• Generation: First-generation gonane (parent compound of gonane class)
• Stereochemistry: Racemic (1:1 dextro:levo)
• Route: Oral

Structural Characteristics:

Norgestrel is a racemic mixture of:

1. Levonorgestrel (d-norgestrel): 13β-ethyl isomer - BIOLOGICALLY ACTIVE
2. Dextronorgestrel (l-norgestrel): 13α-ethyl isomer - INACTIVE

Key Structural Features:

Relationship to Levonorgestrel:

1.3 Historical Background

Development Timeline:

• 1963: Norgestrel discovered by Hughes and colleagues at Wyeth via structural modification of norethisterone
• 1966: First oral contraceptive containing norgestrel approved by FDA
• 1968-1973: Clinical trials leading to Ovrette (progestin-only) approval
• 1973: Ovrette (norgestrel 0.075 mg) approved as progestin-only pill
• 1970s: Schering AG isolated levonorgestrel as the active isomer
• 1975: Levonorgestrel-containing products introduced (more potent)
• 2005: Ovrette discontinued in U.S. (marketing reasons, not safety)
• 2017: FDA determination that Ovrette withdrawal was not for safety/effectiveness
• 2017: NDA approved for name change to Opill
• July 2023: FDA approved Opill for OTC sale (first OTC daily oral contraceptive)
• March 2024: Opill became available in retail stores (Walmart, CVS, Target, Walgreens)

Key Milestones:

1. First totally synthetic progestin: Norgestrel was the first progestin manufactured via total chemical synthesis (not derived from natural steroids)
2. Parent of gonane class: Led to development of levonorgestrel, desogestrel, gestodene
3. First OTC oral contraceptive: Opill represents landmark in reproductive healthcare access

1.4 Clinical Context and Rationale

Why Norgestrel Is Used:

1. Progestin-only contraception: No estrogen-related VTE, MI, stroke risks
2. OTC accessibility: First daily OC available without prescription (U.S.)
3. International HRT use: Combined with estradiol in some formulations (Cyclo-Progynova)
4. Lower cost: Racemic mixture simpler to synthesize than pure levonorgestrel

Norgestrel vs. Levonorgestrel:

Practical Equivalence:

For clinical purposes:

• Norgestrel 0.075 mg ≈ Levonorgestrel 0.0375 mg (active drug delivered)
• Norgestrel 0.5 mg ≈ Levonorgestrel 0.25 mg (in HRT combinations)

Current Role:

• Contraception: Opill OTC provides estrogen-free option for self-directed contraception
• HRT: Limited use; Cyclo-Progynova available internationally but not commonly used in U.S.
• Historical: Largely replaced by pure levonorgestrel in most applications

2. Mechanism of Action

2.1 Molecular Mechanism

Progesterone Receptor Agonism:

The biological activity of norgestrel resides entirely in the levonorgestrel component. The dextronorgestrel isomer does not bind progesterone receptors and is pharmacologically inert.

Mechanism (via Levonorgestrel Component):

1. Receptor binding: Levonorgestrel binds to cytoplasmic progesterone receptor (PR)
2. Receptor activation: Ligand-receptor complex dimerizes
3. Nuclear translocation: PR dimer enters nucleus
4. DNA binding: Binds to progesterone response elements (PREs)
5. Gene regulation:
   • Upregulation: 17β-HSD type 2 (inactivates estradiol)
   • Downregulation: Estrogen receptor α (ER-α)
   • Cell cycle effects: Inhibition of proliferation markers (Ki-67)

Contraceptive Mechanisms:

HRT Mechanisms:

When combined with estrogen (Cyclo-Progynova):

• Endometrial protection: Opposes estrogen-induced proliferation
• Secretory transformation: Induces secretory changes, prevents hyperplasia
• Withdrawal bleeding: Predictable menstruation with sequential regimen

2.2 Receptor Selectivity Profile

Relative Binding Affinities (via Levonorgestrel Component):

Since norgestrel's activity comes from levonorgestrel, receptor affinities are identical to levonorgestrel but effectively at half the concentration per milligram.

Note: These affinities are for the levonorgestrel component. Since norgestrel is 50% inactive dextronorgestrel, the effective affinity per milligram of norgestrel is half of pure levonorgestrel.

Androgenic Considerations:

• Norgestrel (via levonorgestrel) is one of the more androgenic progestins
• Androgenic effects include: decreased SHBG, decreased HDL, acne, hirsutism
• At contraceptive doses (0.075 mg), androgenic effects are generally mild

2.3 Pharmacological Effects by System

Reproductive System:

Hypothalamic-Pituitary Axis:

• FSH: Modest suppression
• LH: Blunts LH surge (variable)
• Ovulation: Inhibited in 40-60% of cycles with norgestrel 0.075 mg

Metabolic Effects:

Bone:

• Progestin-only contraceptives generally have neutral effect on BMD
• No concern for bone loss with norgestrel (unlike DMPA)

3. Indications and Uses

3.1 FDA-Approved Indications

Opill (Norgestrel 0.075 mg):

1. Prevention of pregnancy - OTC contraceptive indication
   • First daily oral contraceptive approved for nonprescription use in U.S.
   • Available to all ages without prescription

Combined Oral Contraceptives (Norgestrel + EE):

1. Prevention of pregnancy - Prescription products (Lo/Ovral, Cryselle)

3.2 Off-Label and International Uses

Menopausal Hormone Therapy (International):

Cyclo-Progynova Regimen:

• Days 1-11: White tablets (estradiol valerate 2 mg alone)
• Days 12-21: Brown tablets (estradiol valerate 2 mg + norgestrel 0.5 mg)
• Days 22-28: No tablets (hormone-free interval; withdrawal bleeding occurs)

Indications for Cyclo-Progynova:

1. Treatment of menopausal symptoms (hot flashes, night sweats, vaginal atrophy)
2. Prevention of postmenopausal osteoporosis

Note: Cyclo-Progynova is NOT marketed in the United States.

3.3 Dosing for Various Applications

Contraception (Opill):

HRT (Cyclo-Progynova):

3.4 Comparison: Norgestrel vs. Other Progestin-Only Pills

Key Distinction:

• Traditional POPs (norgestrel, norethindrone): Rely primarily on cervical mucus; narrower dosing window (3 hours)
• Newer POPs (drospirenone): Consistently inhibit ovulation; wider dosing window (24 hours)

4. Dosing and Administration

4.1 Contraceptive Dosing (Opill)

Standard Dosing:

Missed Dose Management:

Starting Opill:

4.2 HRT Dosing (Cyclo-Progynova)

Sequential Regimen:

Administration:

• Take one tablet daily at approximately the same time
• Start new pack after 7-day tablet-free interval
• Expect withdrawal bleeding during tablet-free days

Duration of HRT:

• Use lowest effective dose for shortest duration
• Reassess need annually
• Sequential regimen appropriate for perimenopausal women or those preferring cyclical bleeding

4.3 Dose Adjustments

Hepatic Impairment:

• Contraindicated in active liver disease or liver tumors
• Use with caution in mild hepatic impairment

Renal Impairment:

• No dose adjustment required (minimal renal excretion of active drug)

Elderly:

• Not applicable for contraception
• HRT: Standard dosing; increased monitoring for VTE, cardiovascular events

Drug Interactions:

• CYP3A4 inducers decrease norgestrel effectiveness
• See Section 7 for complete drug interactions

4.4 Special Considerations

Body Weight:

• Efficacy of norgestrel POP not significantly affected by body weight
• Unlike emergency contraception, daily use maintains consistent drug levels

Breastfeeding:

• Compatible with breastfeeding
• Small amounts enter breast milk but no adverse effects on infant
• May be started immediately postpartum

Postpartum Timing:

5. Pharmacokinetics and Pharmacodynamics

5.1 Absorption

Oral Bioavailability:

Note: Only the levonorgestrel component (50% of dose) is biologically active. The dextronorgestrel component is absorbed but pharmacologically inert.

Effective Drug Delivery:

• Norgestrel 0.075 mg delivers ~0.0375 mg active levonorgestrel
• Norgestrel 0.5 mg (HRT) delivers ~0.25 mg active levonorgestrel

5.2 Distribution

SHBG Dynamics:

• Norgestrel/levonorgestrel has high affinity for SHBG
• Norgestrel suppresses hepatic SHBG synthesis (androgenic effect)
• Net effect: Decreased SHBG, increased free levonorgestrel and testosterone

5.3 Metabolism

Metabolic Pathways:

Key Metabolites:

• 3α,5β-tetrahydrolevonorgestrel: Major circulating metabolite
• 16β-hydroxylevonorgestrel: Minor metabolite
• Sulfate/glucuronide conjugates: Urinary excretion forms

CYP3A4 Sensitivity:

Norgestrel (via levonorgestrel) is a sensitive CYP3A4 substrate:

• CYP3A4 inducers decrease levonorgestrel levels by ~50%
• CYP3A4 inhibitors increase levonorgestrel levels by ~50%

Dextronorgestrel:

• Also metabolized but produces no pharmacological effect
• Contributes to total drug-related material in plasma but not to efficacy

5.4 Elimination

Clinical Implications:

• Long half-life supports once-daily dosing
• Steady-state achieved in ~5 days
• After discontinuation, drug cleared within 3-5 days

5.5 Pharmacodynamic Effects

Contraceptive Effects:

Onset of Effect:

• Cervical mucus thickening: Within 24-48 hours
• Full contraceptive effect: After 48 hours of continuous use

HRT Effects (with Estrogen):

5.6 Comparison: Norgestrel vs. Levonorgestrel Pharmacokinetics

6. Side Effects and Safety Profile

6.1 Common Side Effects

Progestin-Only Contraception (Opill):

HRT Use (Cyclo-Progynova):

6.2 Serious Adverse Effects

Cardiovascular:

Key Point: Progestin-only norgestrel (Opill) does NOT carry the VTE risk associated with estrogen-containing products.

Hepatic:

• Contraindicated in active liver disease
• Rare: Hepatic adenoma (association with long-term OC use)
• Very rare: Hepatocellular carcinoma

Breast Cancer:

Ovarian Cysts:

• Functional ovarian cysts may occur with progestin-only pills
• Usually resolve spontaneously
• Rarely symptomatic

6.3 Androgenic Side Effects

Mechanism: Levonorgestrel component binds androgen receptors and suppresses SHBG.

Metabolic Androgenic Effects:

• SHBG decrease: 10-20% reduction
• Free testosterone increase: Modest; clinical significance varies
• HDL decrease: 5-10% (mild, reversible)

Clinical Perspective:

At norgestrel 0.075 mg, androgenic effects are generally mild and well-tolerated. Most users do not experience clinically significant androgenic symptoms.

6.4 Bleeding Pattern Effects

Progestin-Only Use (Opill):

Counseling Points:

1. Irregular bleeding is COMMON and does NOT indicate method failure
2. Bleeding patterns typically improve after 3-6 months
3. Amenorrhea is safe and not harmful
4. Persistent heavy bleeding warrants evaluation

HRT Use (Cyclo-Progynova):

• Sequential regimen produces predictable withdrawal bleeding
• Bleeding expected during 7-day hormone-free interval
• Unscheduled bleeding requires investigation after 3 months

6.5 Comparison to Other Progestin Safety Profiles

7. Drug Interactions

7.1 CYP3A4 Inducers (Reduce Efficacy)

Strong CYP3A4 Inducers:

Clinical Management:

• If CYP3A4 inducer is essential, use backup contraception during treatment and for 28 days after discontinuation
• Consider non-oral contraception (copper IUD, LNG-IUD, DMPA) for long-term use with enzyme inducers
• Opill OTC labeling advises backup method with "certain medicines"

7.2 CYP3A4 Inhibitors (Increase Levels)

Strong CYP3A4 Inhibitors:

Clinical Note: Unlike with CYP3A4 inducers, increased levels from inhibitors rarely require dose adjustment. Monitor for increased progestogenic side effects (breast tenderness, mood changes, irregular bleeding).

7.3 Interactions Affecting Norgestrel Absorption

7.4 Effects of Norgestrel on Other Drugs

Norgestrel May Affect:

Important Note on Lamotrigine:

• Progestins (including norgestrel) induce lamotrigine metabolism
• Seizure control may decrease during hormonal use
• Lamotrigine dose may need increase by 25-50%
• Careful monitoring during initiation and discontinuation

7.5 Antibiotic Interactions

No Significant Interaction:

Most antibiotics do NOT affect norgestrel efficacy:

Exception - Rifamycins:

• Rifampin, rifabutin, rifapentine: Strong CYP3A4 inducers - reduce norgestrel efficacy
• Use alternative contraception

7.6 Complete Drug Interaction Summary Table

8. Contraindications and Precautions

8.1 Absolute Contraindications

Progestin-Only Norgestrel (Opill):

Combined HRT (Cyclo-Progynova):

All above PLUS:

8.2 Relative Contraindications (Caution)

Progestin-Only Norgestrel:

Combined HRT (Cyclo-Progynova):

8.3 US Medical Eligibility Criteria (US MEC) Summary

Progestin-Only Pills (including Opill):

MEC Categories:

• 1 = No restriction
• 2 = Benefits generally outweigh risks
• 3 = Risks generally outweigh benefits
• 4 = Unacceptable health risk

8.4 Warnings and Precautions

Ectopic Pregnancy:

• If pregnancy occurs on progestin-only pill, ~10% are ectopic
• Higher proportion (not absolute risk) compared to no contraception
• Counsel about symptoms: pelvic pain, irregular bleeding, dizziness

Follicular Atresia Failure:

• Functional follicular cysts may develop
• Usually asymptomatic and resolve spontaneously
• Rarely require intervention

STI Protection:

• Norgestrel does NOT protect against STIs/HIV
• Condoms recommended for STI prevention

Thromboembolic Disease (Combined HRT Only):

• Cyclo-Progynova contains estrogen → VTE risk
• Not applicable to Opill (progestin-only)

9. Special Populations

9.1 Pregnancy

FDA Pregnancy Category: X (combined products) / Contraindicated

Key Points:

• If pregnancy occurs while using norgestrel, discontinue
• No need for termination or special monitoring due to exposure
• Studies show no increased risk of birth defects

9.2 Breastfeeding

Advantages for Breastfeeding:

• No estrogen (which may reduce milk production)
• Preferred over combined oral contraceptives during breastfeeding
• Can initiate before 6-week postpartum visit

9.3 Pediatric/Adolescent

Contraception (Opill):

Counseling Focus:

• Importance of consistent timing
• Irregular bleeding is normal initially
• Does not affect future fertility
• Does not protect against STIs

9.4 Geriatric

Contraception:

• Generally not applicable (post-menopausal)

HRT (Cyclo-Progynova):

9.5 Hepatic Impairment

Rationale: Norgestrel undergoes hepatic metabolism. Impaired clearance increases drug exposure and hepatotoxicity risk.

9.6 Renal Impairment

Rationale: Norgestrel is primarily metabolized hepatically with minimal renal excretion of active drug.

9.7 Postpartum

Timing Recommendations:

Advantages Postpartum:

• No delay in lactation initiation
• No effect on breast milk
• VTE-safe (no estrogen)
• Can start before 6-week checkup

9.8 Transgender Individuals

Female-to-Male (Transmasculine):

• May use norgestrel for endometrial suppression if uterus present
• Often combined with testosterone therapy
• Irregular bleeding may occur initially

Male-to-Female (Transfeminine):

• Not typically used
• May be used for endometrial protection if estrogen therapy induced endometrial changes (rare)

10. Monitoring and Follow-Up

10.1 Baseline Assessment (Contraception)

Before Starting Opill (OTC):

Note: Opill is available OTC without healthcare provider evaluation. Self-screening via package labeling guides appropriate use.

10.2 Baseline Assessment (HRT)

Before Starting Cyclo-Progynova:

10.3 Ongoing Monitoring

Contraception (Opill):

No routine visits required for progestin-only pill use.

HRT (Cyclo-Progynova):

10.4 When to Seek Medical Attention

Contact Healthcare Provider If:

10.5 Discontinuation

Contraception:

HRT:

Post-Discontinuation:

• Contraception: No rebound effects; fertility returns within 1-3 cycles
• HRT: Vasomotor symptoms may return; gradual tapering may reduce recurrence

11. Cost and Accessibility

11.1 U.S. Pricing (2024-2025)

Opill (OTC Progestin-Only Contraceptive):

Insurance Coverage:

Note: As an OTC product, Opill can be purchased without insurance, though some insurers may reimburse with prescription.

Combined Oral Contraceptives (with Norgestrel):

11.2 International Pricing

Cyclo-Progynova (HRT):

Availability:

• Cyclo-Progynova: Available Europe, UK, Asia, Latin America, Middle East
• NOT available: United States, Canada, Australia

11.3 Assistance Programs

Opill Access:

Generic Combined OCs:

• Most combined OCs containing norgestrel have affordable generics
• ACA mandate requires coverage without cost-sharing for prescription contraceptives
• Many pharmacies offer $4/$10 generic programs

11.4 Cost Comparison to Alternatives

Value Analysis:

• Opill offers moderate cost for OTC convenience
• Generic POPs may be cheaper with insurance
• Long-acting methods have higher upfront cost but lower annual cost

11.5 Accessibility Considerations

OTC Status (Opill):

Limitations:

• OTC cost may exceed insured prescription cost
• Self-screening may miss contraindications
• Less healthcare provider guidance

Geographic Availability:

12. Clinical Evidence and Efficacy

12.1 Contraceptive Efficacy

Progestin-Only Pill (Norgestrel/Opill):

Comparison to Other Contraceptives:

Key Evidence:

1. Original Ovrette studies (1970s): Established efficacy with pregnancy rates of 1-3% with perfect use
2. WHO studies: Confirmed progestin-only pill efficacy comparable to combined OCs with perfect use
3. FDA review for OTC switch (2023): Confirmed adequate efficacy for non-prescription use

12.2 Efficacy by Mechanism

Contribution of Each Mechanism:

Timing Sensitivity:

• Efficacy depends on consistent daily dosing within 3-hour window
• Missed pills or late doses significantly reduce cervical mucus effect
• This narrow window explains higher typical-use failure rate

12.3 HRT Efficacy (Cyclo-Progynova)

Vasomotor Symptom Relief:

Endometrial Protection:

Bone Protection:

• Combined HRT (including Cyclo-Progynova) shown to prevent postmenopausal bone loss
• Estrogen is primary bone-protective component
• Norgestrel does not interfere with estrogen's bone effects

12.4 Safety Evidence

Cardiovascular Safety (Progestin-Only):

Key Studies:

1. WHO Collaborative Study (1998): No VTE increase with progestin-only OCs
2. Lidegaard et al. (Denmark, 2012): Confirmed low VTE risk with POPs
3. FDA OTC review (2023): Safety data adequate for non-prescription use

Breast Cancer:

12.5 Comparative Effectiveness Studies

Norgestrel vs. Other Progestin-Only Options:

Clinical Implication:

• Norgestrel (Opill) has equivalent efficacy to traditional POPs
• Newer POPs (drospirenone) have better typical-use efficacy due to consistent ovulation inhibition
• All POPs highly effective with perfect use

12.6 Real-World Evidence

Opill Launch Data (2024):

Self-Selection Studies (Pre-OTC):

13. Comparison to Alternatives

13.1 Norgestrel vs. Levonorgestrel

Clinical Equivalence:

• For practical purposes, norgestrel and levonorgestrel are clinically interchangeable
• Dose adjustment accounts for potency difference
• Same receptor profile, same side effects

13.2 Norgestrel vs. Other POPs

When to Choose Norgestrel (Opill):

• OTC access desired
• No healthcare visit preferred
• Estrogen-free option needed
• Cost-conscious (no insurance)

When to Choose Drospirenone (Slynd):

• Wider timing forgiveness needed
• Anti-androgenic effects desired
• Acne/hirsutism concerns
• Consistent ovulation inhibition preferred

13.3 Norgestrel vs. Combined Oral Contraceptives

13.4 Norgestrel vs. Long-Acting Methods

13.5 Norgestrel HRT vs. Alternatives

Cyclo-Progynova vs. Other Sequential HRT:

Cyclo-Progynova vs. Continuous Combined HRT:

13.6 Decision Algorithm

Choosing Norgestrel (Opill) Over Alternatives:

Is estrogen contraindicated or undesired?
  │
  ├── YES → Consider progestin-only options
  │          │
  │          ├── OTC access preferred? → OPILL (norgestrel)
  │          │
  │          ├── 24-hour timing window needed? → Slynd (drospirenone)
  │          │
  │          ├── Long-acting preferred? → Mirena/implant
  │          │
  │          └── Lowest cost? → Generic norethindrone POP
  │
  └── NO → Combined OC may be appropriate

14. Storage and Handling

14.1 Storage Requirements

Opill (Norgestrel 0.075 mg):

Cyclo-Progynova:

14.2 Handling Instructions

Dispensing:

• Keep in original packaging until use
• Do not remove tablets until time of ingestion
• Check expiration date before dispensing

Patient Instructions:

• Store at room temperature
• Avoid extreme heat (car in summer)
• Avoid bathroom storage (humidity)
• Keep away from children
• Do not use expired medication

14.3 Stability

Shelf Life:

Stability Concerns:

• Progestins generally stable at room temperature
• Extreme heat (>40°C) may affect stability
• No refrigeration required

14.4 Disposal

Proper Disposal Methods:

14.5 Travel Considerations

Traveling with Norgestrel:

Time Zone Adjustment:

For significant time changes (>3 hours):

• Gradually adjust timing over several days
• Or take dose at original body-clock time initially
• Critical to maintain 24-hour intervals

15. Goal Archetype Integration (Progestin)

15.1 Progestin Role in Hormone Optimization Goals

Primary Goal Archetypes Where Norgestrel Applies:

15.2 Goal-Specific Protocol Matching

Goal: Estrogen-Free Contraception

Profile: Needs reliable contraception, estrogen contraindicated or undesired
Archetype Match: HIGH
Norgestrel Role: Primary contraceptive agent
Recommended Product: Opill 0.075 mg daily (OTC)
Key Advantage: No VTE risk, OTC access, breastfeeding-safe
Critical Factor: Must maintain 3-hour dosing window

Goal: Menopausal Hormone Therapy with Endometrial Protection

Profile: Perimenopausal or postmenopausal with intact uterus needing symptom relief
Archetype Match: MODERATE
Norgestrel Role: Endometrial protection in sequential regimen
Recommended Product: Cyclo-Progynova (international) or equivalent
Key Advantage: Predictable withdrawal bleeding, adequate protection
Critical Factor: 10-14 days of progestin required per cycle

Goal: Anti-Androgenic Therapy

Profile: Seeking hormone therapy with anti-androgenic benefits (acne, hirsutism)
Archetype Match: LOW - NOT RECOMMENDED
Reason: Norgestrel is an androgenic progestin (AR binding ~30%)
Better Alternatives: Drospirenone, cyproterone acetate, dienogest

15.3 Archetype-Based Selection Algorithm

USER PRESENTS WITH CONTRACEPTION GOAL:
│
├── Estrogen contraindicated? (VTE history, migraine with aura, >35 smoking)
│   ├── YES → Progestin-only options
│   │   ├── OTC access priority? → NORGESTREL (Opill)
│   │   ├── Wider timing window? → Drospirenone (Slynd)
│   │   └── Long-acting preferred? → LNG-IUD, implant
│   └── NO → Combined options available
│
├── Breastfeeding?
│   ├── YES → Norgestrel acceptable immediately postpartum
│   └── NO → Full range of options
│
└── Androgenic concerns (acne, hirsutism)?
    ├── YES → Avoid norgestrel; consider anti-androgenic options
    └── NO → Norgestrel appropriate

USER PRESENTS WITH HRT GOAL:
│
├── Uterus intact?
│   ├── YES → Progestin required for endometrial protection
│   │   ├── Prefer cycling/withdrawal bleeds? → Sequential (Cyclo-Progynova type)
│   │   └── Prefer amenorrhea? → Continuous combined (not norgestrel-based in U.S.)
│   └── NO → Estrogen-alone acceptable
│
└── International vs. U.S.?
    ├── International → Cyclo-Progynova available
    └── U.S. → Norgestrel not commonly used in HRT; consider alternatives

15.4 Progestin Class Comparison for Goal Matching

15.5 Integration with DosingIQ Goal Framework

Mapping to Standard Goal Categories:

16. Age-Stratified Dosing

16.1 Adolescent (Ages 12-17)

Contraception:

Key Adolescent Considerations:

• FDA approved Opill for all ages (no age restriction for OTC purchase)
• No impact on bone mineral density (unlike DMPA)
• Irregular bleeding common and requires counseling
• May be challenging to maintain 3-hour dosing window consistently
• Privacy concerns may favor OTC access

NOT recommended for adolescents:

• HRT combinations (not indicated in this age group)

16.2 Young Adult (Ages 18-35)

Contraception:

Scenario-Based Dosing:

16.3 Reproductive Age (Ages 36-45)

Contraception:

Perimenopause Considerations:

Transition Planning:

Age 40-45 on Norgestrel POP:
│
├── Experiencing menopausal symptoms?
│   ├── YES → Consider adding low-dose estrogen (HRT initiation)
│   │         Continue norgestrel for contraception until menopause confirmed
│   └── NO → Continue norgestrel alone for contraception
│
└── How to confirm menopause while on POP:
    ├── Age >50: 12 months amenorrhea likely indicates menopause
    ├── Age 45-50: Check FSH (>30 IU/L on 2 occasions, 6 weeks apart)
    └── Age <45: FSH unreliable; continue contraception

16.4 Perimenopausal (Ages 45-55)

Dual Role: Contraception + HRT:

Age-Specific Dosing Considerations:

Sequential HRT Dosing (Cyclo-Progynova equivalent):

16.5 Postmenopausal (Ages 55+)

HRT Only (No Contraception Needed):

Age-Based Risk Assessment:

Special Considerations for Older Women:

• If already on HRT, may continue with careful monitoring
• New initiation of HRT after age 60 not recommended
• Consider transitioning to vaginal estrogen only (no systemic progestin needed)
• Annual reassessment mandatory

16.6 Age-Stratified Summary Table

17. Drug Interactions (Comprehensive)

17.1 Critical Interactions Affecting Norgestrel Efficacy

CYP3A4 Inducers - Contraceptive Failure Risk:

Alternative Contraception Options When Using CYP3A4 Inducers:

1. Copper IUD - Not affected by enzyme inducers
2. LNG-IUD (52mg - Mirena) - Local delivery bypasses hepatic metabolism
3. DMPA injection - Less affected (non-oral route)
4. Condoms - Always effective as backup

17.2 CYP3A4 Inhibitors - Increased Norgestrel Levels

Management of Increased Levels:

• Generally well-tolerated
• Monitor for: Breast tenderness, mood changes, bloating, headache
• No dose reduction typically needed
• If side effects intolerable, consider alternative progestin

17.3 HIV Antiretroviral Interactions

Complex Bidirectional Interactions:

HIV Treatment and Contraception Guidance:

1. Consult HIV specialist for regimen-specific advice
2. INSTI-based regimens (dolutegravir, bictegravir) generally safe
3. NNRTI-based regimens (except rilpivirine) reduce POP efficacy
4. Consider long-acting methods (IUD, implant) for reliability

17.4 Interactions Affecting Other Medications

Lamotrigine - Critical Interaction:

Lamotrigine Dose Adjustment Protocol:

Starting Norgestrel in patient on stable lamotrigine:
├── Check baseline lamotrigine level
├── Start norgestrel
├── Recheck lamotrigine level at 2 weeks
├── Adjust lamotrigine dose to maintain therapeutic level
└── Monitor for seizures throughout

Stopping Norgestrel in patient on adjusted lamotrigine:
├── Plan lamotrigine dose reduction
├── Reduce lamotrigine dose by 25-50% at norgestrel discontinuation
├── Recheck level at 2 weeks
└── Monitor for lamotrigine toxicity (dizziness, ataxia, diplopia)

Other Medications Potentially Affected:

17.5 Absorption Interactions

17.6 Herbal and Supplement Interactions

Key Guidance:

• St. John's Wort is the only herbal with established significant interaction
• For other supplements, data is limited but interactions likely minor
• When in doubt, use backup contraception

17.7 Food Interactions

17.8 Drug Interaction Quick Reference Card

RED - Avoid/Alternative Contraception:

• Rifampin, rifabutin
• Phenytoin, carbamazepine, phenobarbital, primidone
• St. John's Wort
• Efavirenz (without backup)

YELLOW - Use Backup or Monitor:

• Oxcarbazepine, topiramate (>200mg)
• Modafinil, aprepitant
• Nevirapine
• Severe GI illness

GREEN - Safe to Use:

• Most antibiotics (penicillins, cephalosporins, macrolides except rifamycins)
• Antacids, PPIs, H2 blockers
• SSRIs, SNRIs
• NSAIDs, acetaminophen
• Most supplements (except St. John's Wort)
• INSTIs (dolutegravir, bictegravir, raltegravir)

18. Bloodwork Impact

18.1 Lipid Panel Effects

Expected Changes with Norgestrel:

Comparison to Other Progestins:

Monitoring Recommendations:

18.2 Glucose and Insulin Effects

Metabolic Parameters:

Diabetic Patients:

• Norgestrel POP is acceptable for diabetics (MEC Category 2)
• Monitor glucose more frequently during initiation
• No dose adjustment of diabetes medications typically needed
• May have slight insulin resistance increase - usually not clinically significant

18.3 Hormone Levels

Effects on Endogenous Hormones:

Timing of Hormone Testing:

18.4 Liver Function Tests

Hepatic Parameters:

Contraindications Based on LFTs:

18.5 Coagulation Parameters

Progestin-Only Effects (Norgestrel POP):

Key Point: Progestin-only norgestrel does NOT affect coagulation parameters significantly. This contrasts with estrogen-containing products which increase several clotting factors.

Combined HRT (Cyclo-Progynova) Effects:

18.6 Thyroid Function

Effects on Thyroid Tests:

Guidance for Thyroid Patients:

• Norgestrel POP alone: No thyroid dose adjustment needed
• Combined HRT: May need levothyroxine dose increase (10-20%)
• Monitor TSH 6-8 weeks after starting estrogen-containing therapy
• Use free T4, not total T4, for monitoring

18.7 Complete Blood Count

Hematologic Effects:

Clinical Note: Women with heavy menstrual bleeding who achieve amenorrhea on norgestrel may see improved iron parameters over time.

18.8 Comprehensive Monitoring Protocol

Baseline Labs (Before Starting):

Follow-Up Labs:

18.9 Interpreting Abnormal Results

Algorithm for Abnormal Lipids:

HDL decreased >15% from baseline:
│
├── Symptomatic (CVD symptoms)? → Urgent cardiology referral
│
├── Other CV risk factors present?
│   ├── YES → Consider switching to lipid-neutral progestin (drospirenone)
│   │         Add lifestyle modifications
│   │         Consider statin if LDL also elevated
│   └── NO → Reassess in 6 months
│           Lifestyle counseling
│           Continue norgestrel if benefits outweigh risks
│
└── Improvement plan:
    ├── Dietary modification (↓saturated fat, ↑fiber)
    ├── Exercise (150 min/week moderate)
    └── Recheck in 3-6 months

Algorithm for Elevated Glucose:

Fasting glucose 100-125 mg/dL (new finding):
│
├── Repeat to confirm
├── Order HbA1c
├── Lifestyle counseling
├── Continue norgestrel (acceptable in prediabetes)
└── Monitor every 3-6 months

Fasting glucose ≥126 mg/dL or HbA1c ≥6.5%:
│
├── Diabetes diagnosis; refer for management
├── Norgestrel can continue (MEC Category 2 for diabetes)
├── Monitor glucose more closely
└── Coordinate with diabetes care team

19. Protocol Integration

19.1 Integration with Estrogen Therapy

Combined Use Scenarios:

Sequential HRT Protocol (Cyclo-Progynova-Style):

Week 1 (Days 1-7):    Estrogen only
Week 2 (Days 8-11):   Estrogen only
Week 3 (Days 12-21):  Estrogen + Norgestrel 0.5 mg
Week 4 (Days 22-28):  No hormones (withdrawal bleed)

Progestin Opposition Requirements:

19.2 Integration with Testosterone Therapy

Female Testosterone + Norgestrel:

Monitoring with Combined Use:

19.3 Integration with Thyroid Protocols

Hypothyroid Patients:

Protocol:

Starting estrogen-containing therapy in hypothyroid patient:
├── Document baseline TSH (should be at goal)
├── Start hormone therapy
├── Recheck TSH at 6-8 weeks
├── If TSH elevated:
│   ├── Increase levothyroxine by 12.5-25 mcg
│   └── Recheck TSH in 6-8 weeks
└── Maintain TSH monitoring every 6-12 months

19.4 Integration with Mental Health Protocols

Depression/Anxiety Management:

Bipolar Disorder:

19.5 Integration with Metabolic Protocols

Weight Management Programs:

Diabetes Management:

19.6 Perioperative Protocol

Surgery Planning:

Perioperative Protocol:

Pre-operative:
├── Assess VTE risk
├── If on norgestrel POP only:
│   └── Continue through surgery (no VTE risk)
├── If on combined HRT:
│   ├── Low VTE risk surgery: May continue
│   └── High VTE risk surgery: Stop 4-6 weeks before
└── Document hormone status in surgical record

Post-operative:
├── If norgestrel POP: Resume immediately if oral intake possible
├── If combined HRT stopped: Resume when mobile (usually 2-4 weeks post-op)
└── VTE prophylaxis per surgical protocol (not affected by POP)

19.7 Emergency and Acute Care Integration

Emergency Contraception:

Acute Illness Management:

19.8 Transition Protocols

Transitioning FROM Norgestrel:

Transitioning TO Norgestrel:

19.9 Comprehensive Care Coordination

Multi-Provider Communication:

Documentation Template:

HORMONE THERAPY SUMMARY
Patient: [Name]
Current Regimen: Norgestrel [dose] [frequency]
Indication: [Contraception/HRT/Other]
Start Date: [Date]
Duration: [Months/Years]

Key Interactions: [List active]
Monitoring Due: [Next labs/appointments]
Last Assessment: [Date, findings]

Special Considerations:
- [List any]

Contact for hormone questions: [Provider name, contact]

20. References

15.1 Primary Literature

1. Hughes A, et al. The synthesis of some 13β-ethyl-gonanes. Steroids. 1963;2(6):693-702.

2. Vessey MP, et al. Progestogen-only oral contraception: findings in a large prospective study. Br J Fam Plann. 1985;10:117-121.

3. McCann MF, Potter LS. Progestin-only oral contraception: a comprehensive review. Contraception. 1994;50(6 Suppl 1):S1-S195.

4. Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal contraceptives: further results. Contraception. 1996;54(3 Suppl):1S-106S.

5. WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Cardiovascular disease and use of oral and injectable progestogen-only contraceptives. Contraception. 1998;57:315-324.

6. Lidegaard Ø, et al. Thrombotic stroke and myocardial infarction with hormonal contraception. N Engl J Med. 2012;366:2257-2266.

7. FDA. Opill (norgestrel) Drug Approval Package. NDA 017031. July 2023.

8. Perrigo Company. Opill Prescribing Information (Drug Facts Label). 2024.

15.2 Clinical Guidelines

1. American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin No. 206: Use of hormonal contraception in women with coexisting medical conditions. Obstet Gynecol. 2019;133(2):e128-e150.

2. Centers for Disease Control and Prevention (CDC). U.S. Medical Eligibility Criteria for Contraceptive Use (US MEC). MMWR. 2016;65(3):1-103. Updated 2020.

3. World Health Organization (WHO). Medical eligibility criteria for contraceptive use. 5th edition. 2015.

4. North American Menopause Society (NAMS). The 2022 hormone therapy position statement. Menopause. 2022;29(7):767-794.

5. Faculty of Sexual and Reproductive Healthcare (FSRH). Progestogen-only Pills. Clinical Guideline. 2022.

6. International Menopause Society (IMS). Updated 2024 recommendations on menopausal hormone therapy. Climacteric. 2024.

15.3 Drug Information Resources

1. Lexicomp. Norgestrel: Drug Information. UpToDate. 2024.

2. Micromedex. Norgestrel. IBM Watson Health. 2024.

3. American Hospital Formulary Service (AHFS). Drug Information. Norgestrel. 2024.

4. British National Formulary (BNF). Norgestrel. 2024.

5. Martindale: The Complete Drug Reference. Norgestrel. Pharmaceutical Press. 2024.

15.4 Pharmacokinetic Studies

1. Fotherby K. Pharmacokinetics and metabolism of progestins in humans. In: Pharmacology of the Contraceptive Steroids. 1994:99-126.

2. Kuhl H. Pharmacokinetics of oestrogens and progestogens. Maturitas. 1990;12:171-197.

3. Stanczyk FZ. Pharmacokinetics and potency of progestins used for hormone replacement therapy and contraception. Rev Endocr Metab Disord. 2002;3:211-224.

4. Sitruk-Ware R. New progestagens for contraceptive use. Hum Reprod Update. 2006;12(2):169-178.

15.5 Historical and Regulatory Sources

1. Djerassi C. This Man's Pill: Reflections on the 50th Birthday of the Pill. Oxford University Press. 2001.

2. FDA. Determination that Ovrette (Norgestrel) Tablets, 0.075 mg, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness. Federal Register. 2017;82(232):57292.

3. FDA. FDA approves first nonprescription daily oral contraceptive. Press Release. July 13, 2023.

4. Perrigo Company. Opill citizen petition for nonprescription status. FDA Docket. 2023.

15.6 Safety and Pharmacovigilance

1. Gronich N, et al. Higher risk of venous thrombosis associated with drospirenone-containing oral contraceptives. CMAJ. 2011;183(18):E1319-E1325.

2. de Bastos M, et al. Combined oral contraceptives: venous thrombosis. Cochrane Database Syst Rev. 2014;(3):CD010813.

3. ESHRE Capri Workshop Group. Venous thromboembolism in women: a specific reproductive health risk. Hum Reprod Update. 2013;19(5):471-482.

4. Stegeman BH, et al. Different combined oral contraceptives and the risk of venous thrombosis. BMJ. 2013;347:f5298.

15.7 HRT-Specific References

1. Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. JAMA. 2002;288(3):321-333.

2. Baber RJ, et al. 2016 IMS Recommendations on women's midlife health and menopause hormone therapy. Climacteric. 2016;19(2):109-150.

3. The NAMS 2017 Hormone Therapy Position Statement Advisory Panel. The 2017 hormone therapy position statement of The North American Menopause Society. Menopause. 2017;24(7):728-753.

15.8 Product Information

1. Perrigo Company plc. Opill (norgestrel tablets, 0.075 mg) Drug Facts Label. 2024.

2. Bayer HealthCare. Cyclo-Progynova Summary of Product Characteristics (SmPC). European Medicines Agency. Current version.

3. Teva Pharmaceuticals. Cryselle (norgestrel and ethinyl estradiol tablets) Prescribing Information. 2023.

Document Footer

Document Completion: 2025-12-26 Status: PAPER 38 OF 76 COMPLETE Total Length: ~1,600 lines (all 15 sections) Author: EpiqAminos Research Division

Revision History:

Next Paper: #39 - Drospirenone - Spironolactone-derived progestin with anti-androgenic and antimineralocorticoid properties

End of Document