Microgynon 21 (Ethinylestradiol, Levonorgestrel)

Microgynon 21, a combined oral contraceptive, is used to manage reproductive hormone pathways.

• Prevention of pregnancy: provides reliable contraceptive protection for women of childbearing potential.
• Regulation of menstrual cycles: helps achieve more predictable bleeding patterns.
• Treatment of acne: can improve hormonal acne by reducing androgenic activity.

• Ethinylestradiol and levonorgestrel act together to suppress the mid‑cycle surge of luteinising hormone (LH) and follicle‑stimulating hormone (FSH), thereby inhibiting ovulation. The estrogen component stabilises the endometrial lining, while the progestogen thickens cervical mucus and induces endometrial changes that reduce the likelihood of implantation.

Common Side Effects

• Nausea: mild to moderate stomach upset, especially during the first cycles.
• Breast tenderness: temporary swelling or discomfort of the breasts.
• Headache: occasional tension‑type or migraine‑like headaches.
• Breakthrough bleeding: spotting between periods, often resolves with continued use.
• Weight gain: slight fluid retention reported by some users.
• Mood changes: mild fluctuations in mood or irritability.

Serious or Rare Side Effects

• Venous thromboembolism: deep‑vein thrombosis or pulmonary embolism, requiring immediate medical attention.
• Arterial thrombosis: stroke or myocardial infarction, particularly in high‑risk individuals.
• Severe allergic reaction: rash, swelling, or anaphylaxis.
• Liver dysfunction: jaundice or abnormal liver enzymes.
• Hypertension: significant rise in blood pressure.

Before prescribing Microgynon 21, clinicians should evaluate individual risk factors and contraindications.

• Contraindications: known or suspected pregnancy, active thromboembolic disease, estrogen‑dependent tumor, uncontrolled hypertension, severe liver disease.
• Smoking: avoid use in women over 35 who smoke due to increased cardiovascular risk.
• Medical history: assess cardiovascular, hepatic, and migraine history before initiation.
• Drug interactions: review concomitant medications that may reduce efficacy or increase hormone levels.
• Pregnancy and lactation: not recommended; discuss alternative methods with patients.
• Store at ambient temperature below 25°C: keep in the original pack, protect from moisture and light.

Microgynon 21 may interact with several medicines that alter hormone metabolism or efficacy.

Major Interactions (Avoid)

• Potent enzyme inducers (e.g., rifampicin, carbamazepine): may markedly reduce contraceptive effectiveness.
• Antifungal azoles (e.g., ketoconazole): can increase hormone concentrations, raising the risk of side effects.
• Protease inhibitors (certain antiretrovirals): may alter hormone metabolism and affect efficacy.

Moderate Interactions (Monitor Closely)

• Selective serotonin reuptake inhibitors (SSRIs): may affect bleeding patterns.
• St. John’s wort and other herbal supplements: can lower contraceptive reliability.
• Diuretics: may exacerbate hypertension or electrolyte disturbances.