Amorina: Uses, Dosage & Side Effects
A combined oral contraceptive pill containing levonorgestrel and ethinylestradiol for reliable pregnancy prevention
Amorina is a combined oral contraceptive pill (often referred to as “the pill”) that contains two active hormones: levonorgestrel 0.25 mg (a second-generation synthetic progestogen) and ethinylestradiol 0.035 mg (a synthetic estrogen). It is a monophasic contraceptive, meaning each active tablet delivers the same fixed dose of both hormones throughout the cycle. Amorina is primarily prescribed for the prevention of pregnancy and, when taken correctly, provides over 99% effectiveness. It may also be used to regulate menstrual cycles, reduce heavy or painful periods, and manage certain hormonal conditions. Amorina requires a prescription and should only be used under the guidance of a qualified healthcare professional.
Quick Facts: Amorina
Key Takeaways
- Amorina is a monophasic combined oral contraceptive containing levonorgestrel 0.25 mg and ethinylestradiol 0.035 mg that is over 99% effective at preventing pregnancy when taken correctly and consistently.
- Combined oral contraceptives carry a small but significant increased risk of venous thromboembolism (blood clots); the risk is highest in the first year of use and in women who smoke, are overweight, or have additional risk factors.
- Take one tablet daily at the same time for 21 days, followed by a 7-day tablet-free break during which a withdrawal bleed occurs; contraceptive protection continues during the pill-free interval if pills were taken correctly.
- Certain medications including enzyme-inducing drugs (rifampicin, carbamazepine, phenytoin) and herbal products (St John’s Wort) can significantly reduce the contraceptive effectiveness of Amorina; always inform your prescriber of all medications you take.
- Amorina is not suitable during breastfeeding (especially in the first 6 months), during pregnancy, or for women with a history of blood clots, certain heart conditions, breast cancer, or severe liver disease.
What Is Amorina and What Is It Used For?
Amorina belongs to the class of combined hormonal contraceptives (CHCs), which are among the most widely used methods of reversible contraception worldwide. The World Health Organization (WHO) includes levonorgestrel-containing oral contraceptives on its Model List of Essential Medicines, recognizing their importance in reproductive healthcare. Combined oral contraceptives have been available since the 1960s and have undergone extensive refinement over the decades, with modern formulations using lower hormone doses to minimize side effects while maintaining high efficacy.
The two active ingredients in Amorina work together through complementary mechanisms to provide reliable contraception. Levonorgestrel, classified as a second-generation progestogen derived from 19-nortestosterone, is the primary contraceptive component. It suppresses the mid-cycle surge of luteinizing hormone (LH) from the anterior pituitary gland, which is the hormonal signal that triggers ovulation. Without this LH surge, the ovary does not release a mature egg, and fertilization cannot occur. Additionally, levonorgestrel thickens the cervical mucus, creating a physical barrier that impedes sperm transport through the cervical canal. It also induces changes in the endometrium (the lining of the uterus) that make it less receptive to implantation.
Ethinylestradiol, the synthetic estrogen component, plays a supporting role in contraception by further suppressing follicle-stimulating hormone (FSH), which prevents the development of a dominant ovarian follicle. Beyond its contraceptive contribution, ethinylestradiol stabilizes the endometrium, which provides good cycle control and prevents irregular breakthrough bleeding that might otherwise occur with a progestogen-only approach. The 0.035 mg dose of ethinylestradiol in Amorina is considered a standard-dose formulation, as modern low-dose pills typically contain 0.020–0.030 mg.
Amorina is a monophasic preparation, meaning that every active tablet in the pack contains the same fixed dose of both levonorgestrel (0.25 mg) and ethinylestradiol (0.035 mg). This distinguishes it from biphasic or triphasic pills, where hormone doses vary across the cycle. The monophasic design offers the practical advantage of simplified dosing—there is no need to worry about taking tablets in a specific order, and if a pack contains tablets of only one color, any active tablet from the pack provides the same contraceptive protection.
When taken correctly and consistently (perfect use), combined oral contraceptives like Amorina have a failure rate of approximately 0.3% per year, making them one of the most effective reversible contraceptive methods available. In typical use, which accounts for occasional missed pills and other real-world inconsistencies, the failure rate rises to approximately 7–9% per year. This difference underscores the importance of taking Amorina at the same time every day and understanding what to do if a pill is missed.
Beyond pregnancy prevention, Amorina may be prescribed for several additional clinical indications:
- Menstrual cycle regulation: Amorina provides predictable, regular withdrawal bleeds every 28 days, which can be beneficial for women with irregular cycles.
- Dysmenorrhea (painful periods): By suppressing ovulation and reducing endometrial proliferation, combined oral contraceptives significantly reduce the severity of menstrual cramps in many women.
- Menorrhagia (heavy periods): The thinning effect on the endometrium typically results in lighter, shorter withdrawal bleeds compared to natural menstrual periods.
- Acne management: The anti-androgenic effect of estrogen-containing contraceptives can improve hormonally driven acne, although Amorina is not specifically indicated for acne treatment.
- Endometriosis symptom management: Continuous or cyclical use of combined oral contraceptives is a recognized medical treatment for endometriosis-related pain.
- Premenstrual syndrome (PMS): Some women experience improvement in premenstrual symptoms when using combined oral contraceptives.
Amorina does not protect against sexually transmitted infections (STIs), including HIV. If protection against STIs is needed, barrier methods such as condoms should be used in addition to Amorina. Combined oral contraceptives should only be used by women for whom they have been prescribed; they are not suitable for everyone, and a thorough medical assessment is required before starting.
What Should You Know Before Taking Amorina?
Contraindications
There are specific medical conditions and circumstances in which Amorina must not be used (absolute contraindications). These are based on the WHO Medical Eligibility Criteria for Contraceptive Use and are supported by extensive clinical evidence. Understanding these contraindications is essential for safe use.
- History of venous thromboembolism (VTE): Women with a current or past history of deep vein thrombosis (DVT) or pulmonary embolism (PE) must not use Amorina. The estrogen component increases the risk of blood clot formation, and women with a prior history are at substantially elevated risk of recurrence.
- History of arterial thromboembolism: Women who have had a stroke (cerebrovascular accident) or myocardial infarction (heart attack) must not use combined oral contraceptives.
- Known thrombophilia: Inherited or acquired conditions that increase blood clotting risk, such as Factor V Leiden mutation, prothrombin mutation, protein C deficiency, protein S deficiency, or antithrombin deficiency, are contraindications.
- Breast cancer: Current breast cancer or a history of breast cancer within the past 5 years is a contraindication, as combined oral contraceptives may promote growth of hormone-sensitive tumors.
- Severe liver disease: Active liver disease, liver tumors (benign or malignant), or severe hepatic impairment preclude use of Amorina, as the hormones are metabolized by the liver.
- Undiagnosed vaginal bleeding: Abnormal vaginal bleeding that has not been investigated must be evaluated before starting combined oral contraceptives.
- Pregnancy: Amorina must not be used during pregnancy. Although accidental exposure during early pregnancy has not been shown to cause birth defects, the medication serves no purpose during pregnancy and should be stopped immediately upon confirmed pregnancy.
- Migraine with aura: Women who experience migraine headaches accompanied by aura (visual disturbances, sensory symptoms) have an increased risk of ischemic stroke when using combined oral contraceptives.
- Smoking over age 35: Women who smoke and are 35 years of age or older have a markedly increased risk of serious cardiovascular events (heart attack, stroke) when using combined oral contraceptives. This is a WHO Category 4 contraindication (should not be used).
- Severe hypertension: Uncontrolled or severe hypertension (systolic ≥160 mmHg or diastolic ≥100 mmHg) is a contraindication.
Warnings and Precautions
All combined hormonal contraceptives increase the risk of venous thromboembolism (VTE). The risk is highest during the first year of use and when restarting after a break of 4 weeks or more. Seek immediate medical attention if you experience sudden severe leg pain or swelling, sudden unexplained breathlessness, sudden chest pain, sudden severe headache, or sudden vision changes. These may be signs of a blood clot.
Several conditions require careful consideration and ongoing monitoring when using Amorina. Your prescriber will weigh the benefits against the risks for your individual situation:
- Venous thromboembolism risk: The absolute risk of VTE in healthy, non-smoking women under 35 using levonorgestrel/ethinylestradiol combinations is approximately 5–7 per 10,000 women per year, compared to 2 per 10,000 for non-users. Risk factors that further increase this risk include obesity (BMI ≥30), prolonged immobility, recent major surgery, family history of VTE, and increasing age.
- Cardiovascular risk: Combined oral contraceptives may slightly increase blood pressure. Blood pressure should be monitored regularly. Women with controlled hypertension should discuss risks and benefits with their healthcare provider.
- Breast cancer risk: Current evidence suggests a small increase in the relative risk of breast cancer diagnosis among current and recent users of combined oral contraceptives. This increased risk diminishes gradually after stopping and returns to baseline within approximately 10 years. The absolute increase in risk is small, particularly in younger women.
- Cervical cancer: Long-term use (more than 5 years) of combined oral contraceptives is associated with a slightly increased risk of cervical cancer, though this risk returns to normal within 10 years of stopping.
- Liver effects: Rare cases of benign liver tumors (hepatic adenoma) have been associated with long-term use of combined oral contraceptives. In extremely rare cases, malignant liver tumors have been reported. Seek medical attention if you develop severe upper abdominal pain.
- Depression and mood changes: Some women report mood changes or depression while using combined oral contraceptives. If you experience significant mood changes, discuss this with your prescriber.
Pregnancy and Breastfeeding
Amorina is contraindicated during pregnancy. If pregnancy is suspected or confirmed, stop taking Amorina immediately and consult your healthcare provider. Extensive epidemiological studies have found no evidence of increased risk of birth defects in children born to women who inadvertently took combined oral contraceptives during early pregnancy. Nevertheless, Amorina is not intended for use during pregnancy.
Amorina is generally not recommended during breastfeeding. The estrogen component (ethinylestradiol) may reduce the quantity and quality of breast milk, particularly during the early postpartum period when lactation is being established. Small amounts of both hormones are excreted into breast milk. The WHO Medical Eligibility Criteria classify combined oral contraceptives as:
- Category 4 (should not be used): for breastfeeding women less than 6 weeks postpartum
- Category 3 (risks generally outweigh benefits): for breastfeeding women 6 weeks to 6 months postpartum
- Category 2 (benefits generally outweigh risks): for breastfeeding women more than 6 months postpartum
Progestogen-only contraceptive methods (progestogen-only pills, implants, hormonal IUDs, or injectables) are preferred alternatives for breastfeeding women who require hormonal contraception, as they do not significantly affect milk production.
Cigarette smoking significantly increases the risk of serious cardiovascular side effects from combined oral contraceptive use. This risk increases with age and with the number of cigarettes smoked. Women over 35 who smoke should not use combined hormonal contraceptives including Amorina. This is one of the most important safety considerations for prescribers and users of the combined pill.
How Does Amorina Interact with Other Drugs?
Drug interactions are a critically important consideration for women taking Amorina, as certain medications can reduce the contraceptive effectiveness of the pill, potentially leading to unintended pregnancy. The hormones in Amorina are primarily metabolized by cytochrome P450 (CYP) enzymes in the liver, particularly CYP3A4. Drugs that induce (speed up) these enzymes can accelerate the breakdown of levonorgestrel and ethinylestradiol, reducing their blood levels and contraceptive effect.
Conversely, Amorina may affect the metabolism and effectiveness of other drugs. The estrogen component can inhibit certain CYP enzymes and increase blood levels of some co-administered medications, while the progestogen component may have enzyme-inducing or inhibiting effects depending on the specific drug combination.
Major Interactions
The following interactions are considered clinically significant and may require alternative contraceptive methods or dose adjustments:
| Drug / Class | Effect on Amorina | Recommendation |
|---|---|---|
| Rifampicin / Rifabutin | Potent CYP3A4 inducer; markedly reduces contraceptive hormone levels (up to 40% reduction in ethinylestradiol AUC) | Use alternative non-hormonal contraception during treatment and for 28 days after stopping |
| Carbamazepine | Strong enzyme inducer; significantly reduces hormone levels | Use alternative non-hormonal contraception or higher-dose formulation; consult specialist |
| Phenytoin | Strong enzyme inducer; reduces both levonorgestrel and ethinylestradiol levels | Use alternative non-hormonal contraception |
| Phenobarbital / Primidone | Strong enzyme inducers; reduce contraceptive effectiveness | Use alternative non-hormonal contraception |
| St John’s Wort (Hypericum) | Potent CYP3A4 and P-glycoprotein inducer; may cause breakthrough bleeding and contraceptive failure | Do not use concurrently; stop St John’s Wort and use additional contraception for 28 days |
| HIV Protease Inhibitors (e.g., ritonavir, nelfinavir) | Complex interactions; may increase or decrease hormone levels depending on the specific antiretroviral regimen | Consult HIV specialist; additional or alternative contraception often recommended |
| Lamotrigine | Amorina reduces lamotrigine levels by up to 50% during the active pill phase; levels rise in the pill-free week, risking toxicity | Avoid this combination; use alternative contraception or alternative anti-epileptic. If unavoidable, lamotrigine dose adjustment is essential |
Minor Interactions
The following interactions are less clinically significant but may still warrant monitoring or patient counseling:
| Drug / Class | Effect | Recommendation |
|---|---|---|
| Broad-spectrum antibiotics (e.g., amoxicillin, tetracyclines) | Historical concern about reduced pill efficacy; current evidence does not support a significant pharmacokinetic interaction (except rifampicin) | No additional contraception routinely required unless vomiting or severe diarrhea occurs |
| Griseofulvin | May reduce contraceptive efficacy through uncertain mechanism | Use additional barrier contraception during treatment and for 7 days after |
| Modafinil | Weak enzyme inducer; may reduce contraceptive hormone levels | Use additional barrier contraception during and for 28 days after treatment |
| Topiramate (≥200 mg/day) | At higher doses, may induce CYP3A4 and reduce ethinylestradiol levels | Consider alternative contraception at doses ≥200 mg/day |
| Ciclosporin | Amorina may increase ciclosporin blood levels due to CYP3A4 inhibition | Monitor ciclosporin levels; dose adjustment may be needed |
| Prednisolone / Corticosteroids | Ethinylestradiol may increase prednisolone blood levels | Monitor for corticosteroid side effects; dose reduction may be needed |
Always inform your doctor, pharmacist, and dentist that you are taking Amorina before starting any new prescription medication, over-the-counter drug, or herbal supplement. If a newly prescribed medication is known to reduce the effectiveness of combined oral contraceptives, use additional barrier contraception (such as condoms) for the duration of the interacting treatment and for 7–28 days after stopping, depending on the specific interaction. Consult the Faculty of Sexual and Reproductive Healthcare (FSRH) guidelines or your healthcare provider for the most up-to-date advice on individual drug interactions.
What Is the Correct Dosage of Amorina?
Adults
Standard Dosing Regimen
Take one tablet daily at approximately the same time each day for 21 consecutive days, followed by a 7-day tablet-free interval. During the tablet-free interval, a withdrawal bleed (similar to a period) usually occurs within 2–3 days. Start the next pack on day 8 after the last active tablet, regardless of whether the withdrawal bleed has finished.
Timing consistency is important for maintaining reliable contraceptive protection. Taking the tablet at the same time each day helps maintain steady hormone levels and reduces the likelihood of breakthrough bleeding. Many women find it helpful to associate pill-taking with a daily routine activity, such as brushing teeth at night or eating breakfast.
Amorina is intended for use in women of reproductive age, from menarche (first menstrual period) until menopause. There is no upper age limit for use, provided there are no contraindications, although the benefit-risk profile changes with increasing age, particularly in women who smoke. The decision to continue combined oral contraceptives in women approaching menopause should be made in consultation with a healthcare provider.
Starting Amorina for the First Time
- Day 1 start (recommended): Begin taking Amorina on the first day of your menstrual period. Contraceptive protection is immediate—no additional contraception is needed.
- Day 2–5 start: If starting between day 2 and day 5 of your period, use additional barrier contraception (e.g., condoms) for the first 7 days of pill-taking.
- Switching from another combined pill: Start Amorina the day after the last active tablet of the previous pill (no gap needed), or on the day after the pill-free or placebo-tablet interval.
- Switching from a progestogen-only pill: Start Amorina on any day; use additional barrier contraception for the first 7 days.
- After childbirth (non-breastfeeding): Start no earlier than day 21 postpartum. If starting later, use additional barrier contraception for the first 7 days and ensure you are not pregnant.
- After miscarriage or abortion (first trimester): Start immediately for instant contraceptive protection.
Children and Adolescents
Amorina is not indicated for use before menarche. In adolescents who have started menstruating, the same dosing regimen applies as for adult women. The decision to prescribe combined oral contraceptives to adolescents should involve a thorough assessment of the individual’s medical history, cardiovascular risk factors, and maturity to manage the daily pill-taking regimen. There is no evidence that combined oral contraceptives affect growth or bone development in adolescents who have reached menarche.
Elderly
Amorina is not indicated for postmenopausal women. For women approaching menopause, the benefit-risk assessment becomes increasingly important, as the risk of venous and arterial thromboembolism increases with age. The FSRH recommends that women using combined hormonal contraception switch to a progestogen-only or non-hormonal method by age 50, as the risks of combined hormonal methods generally outweigh the benefits after this age.
Missed Dose
What to Do If You Miss a Pill
The advice below is based on the FSRH and WHO missed pill guidelines:
- One pill missed (less than 24 hours late): Take the missed pill as soon as you remember, even if this means taking two pills in one day. Continue the pack as normal. No additional contraception is needed and emergency contraception is not required.
- Two or more pills missed (more than 48 hours late): Take the last missed pill as soon as you remember (discard any other missed pills). Continue taking the remaining pills at the usual time. Use additional barrier contraception (e.g., condoms) for the next 7 days.
- If pills were missed in week 1 (days 1–7): Follow the above advice. If unprotected sexual intercourse occurred during the pill-free interval or in week 1, emergency contraception may be needed. Consult a healthcare professional.
- If pills were missed in week 3 (days 15–21): Follow the above advice, but omit the pill-free interval—start the next pack immediately after finishing the current one.
Overdose
Overdose with combined oral contraceptives is not expected to cause serious harm. Symptoms of overdose may include nausea, vomiting, and, in women and girls, withdrawal bleeding. There is no specific antidote. Treatment is supportive and symptomatic. If a large number of tablets have been ingested, contact a poison control center or seek medical attention.
Vomiting and severe diarrhea can reduce the absorption of Amorina and compromise contraceptive effectiveness. If vomiting occurs within 3–4 hours of taking a tablet, treat this as a missed pill and follow the missed pill guidance above. If severe vomiting or diarrhea continues for more than 24 hours, follow the rules for two or more missed pills and consider using additional barrier contraception until the illness resolves and for 7 days after recovery.
What Are the Side Effects of Amorina?
Like all medicines, Amorina can cause side effects, although not everybody gets them. Most side effects are mild and tend to improve or resolve within the first 2–3 months of use as the body adjusts to the hormones. If side effects persist beyond 3 months or are significantly troublesome, consult your healthcare provider, as an alternative contraceptive formulation or method may be more suitable.
The side effects listed below are organized by frequency category, based on data from clinical trials and post-marketing surveillance. Frequency categories follow the standard convention used by the European Medicines Agency (EMA).
Very Common
May affect more than 1 in 10 women
- Headache
- Breakthrough bleeding or spotting (especially in the first 1–3 cycles)
Common
May affect 1 in 10 to 1 in 100 women
- Nausea
- Breast tenderness, breast pain, or breast enlargement
- Mood changes, including depressed mood and mood swings
- Abdominal pain or bloating
- Weight gain
- Decreased libido (reduced sexual drive)
- Acne (may worsen initially before improving)
- Migraine or worsening of existing migraine
Uncommon
May affect 1 in 100 to 1 in 1,000 women
- Increased blood pressure
- Vomiting or diarrhea
- Fluid retention (edema)
- Skin rash, urticaria (hives), or itching
- Changes in vaginal discharge
- Contact lens intolerance (due to corneal changes)
- Chloasma (brown patches on the face, especially with sun exposure)
- Hair loss (alopecia) or increased hair growth
Rare
May affect 1 in 1,000 to 1 in 10,000 women
- Venous thromboembolism (deep vein thrombosis, pulmonary embolism)
- Arterial thromboembolism (stroke, myocardial infarction)
- Severe allergic reactions (hypersensitivity)
- Gallbladder disease or gallstones
- Pancreatitis (in women with severe hypertriglyceridemia)
- Erythema nodosum or erythema multiforme
Very Rare
May affect fewer than 1 in 10,000 women
- Hepatic adenoma (benign liver tumor)
- Hepatocellular carcinoma (extremely rare)
- Worsening of systemic lupus erythematosus (SLE)
- Worsening of porphyria
- Chorea (involuntary movements)
- Hemolytic uremic syndrome
Contact emergency services or go to the nearest emergency department immediately if you experience any of the following while taking Amorina, as these may be signs of a blood clot or other serious condition:
- Sudden severe leg pain, swelling, warmth, or redness (possible DVT)
- Sudden unexplained shortness of breath or sharp chest pain (possible pulmonary embolism)
- Sudden severe headache or migraine worse than usual, especially with aura for the first time
- Sudden vision changes, loss of vision, or double vision
- Slurred speech, sudden weakness or numbness, especially on one side of the body (possible stroke)
- Sudden severe abdominal pain
If you experience any side effect not listed above, or if any listed side effect becomes severe, consult your healthcare provider or pharmacist. You can also report suspected side effects to your national medicines regulatory authority (e.g., the Yellow Card Scheme in the UK, MedWatch in the USA, or the corresponding system in your country).
How Should You Store Amorina?
Proper storage of Amorina is essential to ensure the medication remains effective throughout its shelf life. The active hormones (levonorgestrel and ethinylestradiol) can degrade if exposed to excessive heat, moisture, or light, which could potentially reduce the contraceptive effectiveness of the tablets.
- Temperature: Store at room temperature, below 25°C (77°F). Do not freeze. Avoid storing in locations that experience temperature extremes, such as in a car during summer or near a radiator.
- Light and moisture: Keep the tablets in the original blister packaging to protect from light and moisture. Do not transfer tablets to other containers.
- Children: Keep out of reach and sight of children. Store in a secure location.
- Expiry date: Do not use Amorina after the expiry date printed on the blister and carton. The expiry date refers to the last day of that month.
- Disposal: Do not dispose of unused tablets by flushing them down the toilet or throwing them in household waste. Return unused or expired medication to your pharmacy for safe disposal. Hormonal medicines that enter the water supply can have environmental effects on aquatic ecosystems.
When traveling, keep Amorina in your hand luggage to avoid temperature extremes in the airplane cargo hold. If traveling across time zones, try to maintain consistent dosing intervals (approximately every 24 hours). If the time difference is significant, take the tablet at a time that is convenient in the new time zone, even if this shortens one dosing interval slightly. Do not extend the interval between doses to more than 36 hours, as this is equivalent to missing a pill.
What Does Amorina Contain?
Active Ingredients
Each film-coated tablet of Amorina contains:
- Levonorgestrel 0.25 mg: A second-generation synthetic progestogen (progestin) derived from 19-nortestosterone. Levonorgestrel is the active levorotatory enantiomer of norgestrel and is one of the most widely used progestogens in hormonal contraception worldwide. It has high progestogenic activity and relatively low androgenic activity at the doses used in combined oral contraceptives.
- Ethinylestradiol 0.035 mg: A potent synthetic estrogen that is the most commonly used estrogenic component in combined oral contraceptives. The 17α-ethinyl group at the C17 position of the estradiol molecule confers oral bioavailability by protecting against first-pass hepatic metabolism. The 0.035 mg dose classifies Amorina as a standard-dose combined oral contraceptive (low-dose pills typically contain 0.020–0.030 mg ethinylestradiol).
Inactive Ingredients (Excipients)
The tablets also contain inactive ingredients (excipients) that are necessary for manufacturing, stability, and appearance. Common excipients found in levonorgestrel/ethinylestradiol tablets may include:
- Lactose monohydrate (tablet filler)
- Maize starch or potato starch (binder/disintegrant)
- Povidone (binder)
- Magnesium stearate (lubricant)
- Talc (glidant)
- Sucrose (coating agent)
- Calcium carbonate (coating component)
- Titanium dioxide (E171, colorant)
- Iron oxide (colorant, if applicable)
- Macrogol (polyethylene glycol, coating agent)
Amorina tablets may contain lactose monohydrate and sucrose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency, glucose-galactose malabsorption, fructose intolerance, or sucrase-isomaltase insufficiency should not take this medicine. If you have any known sugar intolerance, consult your doctor before starting Amorina.
Frequently Asked Questions About Amorina
References
This article is based on peer-reviewed medical literature, international clinical guidelines, and regulatory documents. All medical claims are supported by evidence from systematic reviews, randomized controlled trials, or authoritative clinical guidelines.
- World Health Organization. Medical Eligibility Criteria for Contraceptive Use. 5th edition. Geneva: WHO; 2015 (updated 2024). Available from: who.int/publications
- Faculty of Sexual & Reproductive Healthcare (FSRH). FSRH Clinical Guideline: Combined Hormonal Contraception. London: FSRH; 2019 (updated 2023). Available from: fsrh.org/standards-and-guidance
- European Medicines Agency (EMA). Combined hormonal contraceptives – Assessment of the risk of venous thromboembolism. EMA/738956/2013. London: EMA; 2014.
- Lidegaard Ø, Løkkegaard E, Svendsen AL, Agger C. Hormonal contraception and risk of venous thromboembolism: national follow-up study. BMJ. 2009;339:b2890. doi:10.1136/bmj.b2890
- Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal contraceptives: collaborative reanalysis of individual data on 53,297 women with breast cancer and 100,239 women without breast cancer from 54 epidemiological studies. Lancet. 1996;347(9017):1713-1727.
- Trussell J. Contraceptive failure in the United States. Contraception. 2011;83(5):397-404. doi:10.1016/j.contraception.2011.01.021
- National Institute for Health and Care Excellence (NICE). Contraception. NICE Quality Standard [QS129]. London: NICE; 2016 (updated 2023).
- British National Formulary (BNF). Combined hormonal contraceptives. London: BMJ Group and Pharmaceutical Press; 2024.
- U.S. Food and Drug Administration (FDA). FDA Drug Safety Communication: Updated information about the risk of blood clots in women taking birth control pills containing drospirenone. Silver Spring, MD: FDA; 2012.
- Dragoman MV, Tepper NK, Fu R, Curtis KM, Chou R, Gaffield ME. A systematic review and meta-analysis of venous thrombosis risk among users of combined oral contraception. Int J Gynaecol Obstet. 2018;141(3):287-294. doi:10.1002/ijgo.12455
Editorial Team
This article has been written and reviewed by the iMedic medical editorial team according to our strict editorial standards. Our team consists of licensed physicians, pharmacists, and medical researchers with expertise in clinical pharmacology and reproductive medicine.
Content developed by iMedic’s medical writing team based on current international guidelines (WHO, EMA, FDA, BNF, NICE, FSRH) and peer-reviewed pharmacological research.
Independently reviewed and fact-checked by the iMedic Medical Review Board, comprising board-certified specialists in clinical pharmacology and reproductive medicine.
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