Anastrella: Uses, Dosage & Side Effects

What Is Anastrella and What Is It Used For?

Anastrella belongs to the class of medications known as combined oral contraceptives (COCs), which are among the most widely used and extensively studied forms of reversible contraception globally. The World Health Organization (WHO) lists combined oral contraceptives as essential medicines, reflecting their fundamental importance in family planning and reproductive healthcare worldwide. Anastrella contains two synthetic hormones that work in synergy to provide reliable contraceptive protection: desogestrel, a third-generation progestogen, and ethinylestradiol, a synthetic estrogen.

Desogestrel is a prodrug that is rapidly and completely converted in the body to its biologically active metabolite, etonogestrel (also known as 3-keto-desogestrel), primarily through first-pass metabolism in the intestinal wall and liver. Etonogestrel has a high binding affinity for progesterone receptors and is one of the most potent progestogens available in oral contraceptive formulations. Importantly, desogestrel was developed as a third-generation progestogen with the aim of minimizing androgenic side effects compared to earlier progestogens such as levonorgestrel and norethisterone. This means that Anastrella is less likely to cause androgen-related effects such as acne, hirsutism, and unfavorable changes in lipid profiles, making it a particularly suitable option for women who are sensitive to these effects.

Ethinylestradiol is a potent synthetic estrogen that has been the estrogen component in most combined oral contraceptives since their introduction in the 1960s. At the dose of 30 micrograms used in Anastrella, ethinylestradiol contributes to contraceptive efficacy by synergizing with desogestrel in the suppression of the hypothalamic-pituitary-ovarian axis, thereby preventing the luteinizing hormone (LH) surge that triggers ovulation. Additionally, ethinylestradiol provides cycle control, reducing the incidence of breakthrough bleeding and spotting that can occur with progestogen-only preparations. The 30-microgram dose of ethinylestradiol represents a well-established balance between effective cycle control and minimization of estrogen-related side effects.

The contraceptive mechanism of Anastrella operates through three complementary pathways. The primary mechanism is the suppression of ovulation through the combined action of desogestrel and ethinylestradiol on the hypothalamic-pituitary-gonadal axis. Together, these hormones suppress the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland, preventing follicular maturation and the LH surge required for ovulation. In clinical studies, ovulation has been shown to be effectively inhibited in more than 99% of cycles when Anastrella is taken correctly. The secondary mechanisms provide additional contraceptive protection: the progestogenic effect of etonogestrel thickens the cervical mucus, creating a barrier that impedes sperm penetration into the uterine cavity, and the combined hormonal effect alters the endometrial lining, making it less receptive to implantation.

When taken correctly and consistently (perfect use), combined oral contraceptives like Anastrella are more than 99% effective, with a failure rate of approximately 0.3% per year. Under typical use conditions, which account for occasional missed pills and timing variations, the effectiveness is approximately 91–93%, corresponding to a failure rate of 7–9% per year. These figures underscore the importance of adherence to the daily dosing regimen. Anastrella is formulated as a monophasic pill, meaning each active tablet contains the same dose of both hormones, simplifying the regimen and reducing the risk of confusion compared to multiphasic formulations.

What Should You Know Before Taking Anastrella?

Contraindications

There are several absolute contraindications to the use of Anastrella. You must not take this medication if any of the following conditions apply to you, as the risks significantly outweigh the benefits of hormonal contraception in these situations:

• Venous thromboembolism (VTE): Current or past history of deep vein thrombosis (DVT) or pulmonary embolism (PE), whether on anticoagulant treatment or not. This includes events associated with known thrombophilic conditions such as Factor V Leiden mutation, prothrombin gene mutation, antithrombin III deficiency, protein C deficiency, or protein S deficiency.
• Arterial thromboembolism (ATE): Current or past history of stroke (including transient ischemic attack), myocardial infarction, or angina pectoris.
• Multiple risk factors for thromboembolism: The presence of multiple serious risk factors for arterial or venous thromboembolism, such as age over 35 combined with smoking more than 15 cigarettes per day, severe hypertension (systolic blood pressure ≥160 mmHg or diastolic ≥100 mmHg), diabetes mellitus with vascular complications, or severe dyslipoproteinemia.
• Migraine with aura: Current or past history of migraine with focal neurological symptoms (migraine with aura), as this is associated with a significantly increased risk of ischemic stroke when combined with COC use.
• Liver disease: Severe liver disease with abnormal liver function tests that have not returned to normal, liver tumors (benign or malignant), or active hepatitis.
• Known or suspected hormone-sensitive malignancies: Including breast cancer or endometrial cancer, whether current or within the past 5 years.
• Undiagnosed vaginal bleeding: Any abnormal vaginal bleeding that has not been investigated and diagnosed by a healthcare provider.
• Pancreatitis: Current or history of pancreatitis associated with severe hypertriglyceridemia.
• Hypersensitivity: Known allergy to desogestrel, ethinylestradiol, or any of the excipients in the formulation.

Warnings and Precautions

Before prescribing Anastrella, your healthcare provider should conduct a thorough assessment of your individual risk factors for venous and arterial thromboembolism. Risk factors for VTE include obesity (BMI >30 kg/m²), family history of VTE in a first-degree relative under the age of 45, prolonged immobilization (including long-distance travel), major surgery, and the postpartum period. The risk of VTE is further increased in women with inherited thrombophilias, although routine screening for thrombophilia is not recommended before starting COCs.

Arterial thromboembolism (ATE), including myocardial infarction and ischemic stroke, is a less common but more serious complication of COC use. Risk factors for ATE include smoking (especially over 35 years of age), hypertension, diabetes mellitus, obesity, hyperlipidemia, family history of premature cardiovascular disease, and migraine. Women who smoke and are over 35 years of age are strongly advised not to use combined oral contraceptives.

An association has been observed between COC use and a small increase in the risk of cervical cancer with long-term use (more than 5 years), although this risk gradually returns to baseline after discontinuation. Current evidence also suggests a small increase in the relative risk of breast cancer diagnosis during COC use and in the 10 years after stopping. However, the absolute risk remains very low, particularly in younger women, and must be weighed against the protective effect of COCs against ovarian and endometrial cancers. All women should perform regular breast self-examinations and attend recommended screening programs.

Pregnancy and Breastfeeding

Anastrella is contraindicated during pregnancy. If pregnancy is suspected or confirmed, the medication should be discontinued immediately. However, extensive epidemiological studies have found no increased risk of birth defects in babies born to women who inadvertently took combined oral contraceptives during early pregnancy.

Anastrella is not recommended during breastfeeding. Combined oral contraceptives containing ethinylestradiol can reduce the quantity and alter the composition of breast milk, potentially affecting the nutritional intake of the infant. Small amounts of the contraceptive steroids and their metabolites may be excreted in breast milk. The WHO recommends that breastfeeding women should not use combined oral contraceptives until at least 6 months postpartum, or until the child is substantially weaned. Progestogen-only methods (such as the progestogen-only pill, implant, or hormonal intrauterine device) or non-hormonal contraceptive methods are preferred alternatives during breastfeeding.

After discontinuing Anastrella, the return of fertility is usually prompt. Most women ovulate within the first cycle after stopping the pill, and the median time to conception after stopping COCs is similar to that after stopping non-hormonal contraception. However, it is common to experience a delay of one to two cycles before regular ovulation resumes, and this does not indicate reduced long-term fertility.

How Does Anastrella Interact with Other Drugs?

Major Interactions

The most important drug interactions with Anastrella involve substances that induce hepatic microsomal enzymes, particularly the cytochrome P450 3A4 (CYP3A4) system. These enzyme-inducing drugs accelerate the metabolism of ethinylestradiol and etonogestrel, leading to lower plasma concentrations and potentially reduced contraceptive efficacy. When taking any enzyme-inducing medication, women using Anastrella should use an additional barrier method of contraception (such as condoms) during concurrent treatment and for at least 28 days after discontinuation of the interacting drug. If the enzyme-inducing treatment extends beyond the end of the current pill pack, the next pack should be started immediately without the usual 7-day tablet-free interval.

Minor Interactions

Some medications interact with Anastrella in clinically relevant but less critical ways. Broad-spectrum antibiotics (such as amoxicillin, doxycycline, and ampicillin) were historically thought to reduce the efficacy of COCs by disrupting enterohepatic recirculation of ethinylestradiol. However, modern evidence, including systematic reviews and pharmacokinetic studies, has generally not supported this concern, and current guidelines from the Faculty of Sexual and Reproductive Healthcare (FSRH) and ACOG state that no additional contraceptive precautions are needed during short courses of non-enzyme-inducing antibiotics. The exception is rifampicin and rifabutin, which are potent enzyme inducers and are listed in the major interactions above.

Anastrella may also affect the metabolism of other medications. COCs can increase plasma levels of ciclosporin, prednisolone, and theophylline through inhibition of CYP enzymes. The clinical significance of these interactions varies and should be assessed on an individual basis. COCs may also increase the clearance of lamotrigine (used for epilepsy and bipolar disorder) through induction of glucuronidation, potentially leading to decreased seizure control. When a woman taking lamotrigine starts or stops Anastrella, close monitoring of lamotrigine levels and seizure control is recommended, and dose adjustments may be necessary.

What Is the Correct Dosage of Anastrella?

Adults

The standard dosing regimen for Anastrella follows the well-established 21/7 pattern used by monophasic combined oral contraceptives. One film-coated tablet should be taken orally each day at approximately the same time, with or without food, for 21 consecutive days. The tablet should be swallowed whole with a small amount of water. After completing the 21-day course, a 7-day tablet-free interval (also called a hormone-free interval or pill-free week) follows, during which no tablets are taken. A withdrawal bleed resembling a menstrual period typically begins 2–3 days after the last active tablet and may not have finished before the next pack is started. The next blister pack should always be started on the 8th day after the last active tablet, regardless of whether bleeding has stopped.

First-time use (no prior hormonal contraception): Start on the first day of your menstrual period (Day 1). Contraceptive protection begins immediately, and no additional contraceptive method is needed. If starting on Day 2–5 of the cycle, an additional barrier method (such as condoms) should be used for the first 7 days of tablet-taking.

Switching from another COC: Start Anastrella the day after taking the last active tablet of your previous COC, or at the latest on the day after the tablet-free interval or the last inactive tablet of your previous product.

Switching from a progestogen-only method: You may switch any day from the progestogen-only pill. From an implant or intrauterine system, switch on the day of removal. From an injectable, switch when the next injection is due. In all cases, use a barrier method for the first 7 days.

Children and Adolescents

Anastrella is intended for use in women of reproductive age. It is not indicated for use before menarche. In post-menarchal adolescents, the safety and efficacy of combined oral contraceptives are generally considered similar to those in adults, and the same dosing regimen applies. Healthcare providers should consider the maturity of the hypothalamic-pituitary-ovarian axis and the potential impact on bone mineral density, although current evidence does not indicate a clinically significant effect of COCs on peak bone mass acquisition in adolescents.

Elderly

Anastrella is not indicated for use in postmenopausal women. Combined oral contraceptives are designed for women of reproductive age who require contraception. Women approaching menopause who are still potentially fertile may continue using COCs but should discuss with their healthcare provider whether a lower-dose preparation or alternative contraceptive method may be more appropriate given the increasing cardiovascular risk associated with age.

Missed Dose

The management of missed pills is one of the most important aspects of oral contraceptive use. A pill is considered “missed” if it is taken more than 24 hours late (i.e., more than 12 hours after the usual time). The appropriate action depends on when the pill was missed within the cycle:

Overdose

No serious adverse effects have been reported following acute ingestion of large doses of combined oral contraceptives. Symptoms that may occur include nausea, vomiting, and, in women and girls, withdrawal vaginal bleeding. There is no specific antidote, and management is symptomatic and supportive. If ingestion is suspected within 2–3 hours, gastric lavage may be considered in severe cases, but in most situations, observation and supportive care are sufficient.

Gastrointestinal Disturbances

If vomiting occurs within 3–4 hours of taking a tablet, absorption may be incomplete, and the situation should be managed as if a pill has been missed. If severe diarrhea occurs for more than 24 hours, contraceptive protection may be reduced. Additional barrier contraception should be used during the illness and for 7 days after recovery. If the episode extends into the tablet-free interval, the interval should be omitted and the next pack started immediately.

What Are the Side Effects of Anastrella?

Like all medications, Anastrella can cause side effects, although not everyone experiences them. The side effect profile of Anastrella is consistent with that of other combined oral contraceptives containing desogestrel and ethinylestradiol, as documented in clinical trials and extensive post-marketing surveillance data. Most side effects are mild to moderate in severity and tend to diminish or resolve during the first few months of use as the body adjusts to the hormonal environment. If side effects persist beyond 3 months or are particularly bothersome, consult your healthcare provider to discuss whether an alternative formulation may be more suitable.

The frequency categories below follow the internationally standardized MedDRA classification system used by the European Medicines Agency (EMA) and the WHO:

It is important to note that the risk of venous thromboembolism (VTE) is context-dependent. The absolute risk for women taking desogestrel-containing COCs is estimated at approximately 9–12 per 10,000 women per year, compared to approximately 5–7 per 10,000 for women using levonorgestrel-containing COCs and approximately 2 per 10,000 for non-users who are not pregnant. For perspective, the risk of VTE during pregnancy is approximately 29 per 10,000 women per year, and approximately 300–400 per 10,000 in the immediate postpartum period. The risk of VTE with COC use is highest during the first year of use, particularly the first 3–6 months, and when restarting after a break of 4 weeks or more.

Some women experience changes in mood or depressive symptoms while taking combined oral contraceptives. If you experience persistent low mood, depression, or significant emotional changes, speak with your healthcare provider. Alternative contraceptive methods or formulations may be considered. Approximately 1–3% of women discontinue COCs due to mood-related side effects.

How Should You Store Anastrella?

Anastrella should be stored at a temperature not exceeding 30°C (86°F). The tablets should be kept in the original blister packaging to protect them from light and moisture. Do not remove tablets from the blister until you are ready to take them. The packaging is designed to help you keep track of your daily doses, so it is important to follow the numbered sequence on the blister pack.

Keep this medicine out of the sight and reach of children. Do not use Anastrella after the expiry date stated on the carton and blister pack. The expiry date refers to the last day of that month. Do not dispose of medications via wastewater or household waste. Return any unused or expired medicine to a pharmacy or follow local disposal guidelines to help protect the environment.

If you are traveling, keep your pills in their original packaging and carry them in your hand luggage. Avoid storing them in places subject to extreme temperatures, such as a car dashboard in summer or a freezer. If stored correctly, the tablets maintain their potency and stability throughout the shelf life indicated on the packaging.

What Does Anastrella Contain?

Each film-coated tablet of Anastrella contains the following active ingredients:

• Desogestrel 150 micrograms (0.15 mg) – a third-generation progestogen that is converted to its active metabolite etonogestrel in the body. Etonogestrel has high progestogenic activity with minimal androgenic effects.
• Ethinylestradiol 30 micrograms (0.03 mg) – a potent synthetic estrogen that provides cycle control and contributes to ovulation suppression. The 30-microgram dose represents a standard formulation offering a balance between efficacy and minimization of estrogen-related side effects.

The excipients (inactive ingredients) typically present in desogestrel/ethinylestradiol film-coated tablets include:

• Tablet core: Lactose monohydrate, potato starch, povidone, stearic acid, colloidal anhydrous silica, and alpha-tocopherol (vitamin E, as an antioxidant).
• Film coating: Hypromellose (hydroxypropyl methylcellulose), macrogol (polyethylene glycol), and talc. The film coating may also contain titanium dioxide and other coloring agents depending on the specific formulation.

Important note for patients with lactose intolerance: Anastrella tablets contain lactose monohydrate as an excipient. The amount of lactose per tablet is very small (typically less than 100 mg) and is generally well tolerated even by women with mild to moderate lactose intolerance. However, women with rare hereditary conditions of galactose intolerance, the Lapp lactase deficiency, or glucose-galactose malabsorption should not take this medication. Speak with your doctor if you have concerns about lactose content.