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Микролют

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Микролют

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

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Overview of Микролют

What is Микролют? (Microlut)

This section provides a clear, authoritative overview of the identity, composition, and general purpose of the medicine Микролют (Microlut).

Property Description
Active ingredient Levonorgestrel (INN)
Form Tablets
Pharmacological class Hormonal Contraceptive
Common use Prevention of Pregnancy
Origin Synthetic

Classification and Type of Preparation

Микролют is an oral hormonal contraceptive specifically defined as a Progestogen-Only Pill (POP), often referred to as a minipill. This classification distinguishes this preparation as a Single Product containing only one type of synthetic hormone, Левоноргестрел. Микролют is positioned as a continuous, lower-dose pill, offering a specific type of birth control for women of childbearing potential. Progestogen-Only Pills are characterized as an option for patient groups who may not be suitable candidates for estrogen-containing contraceptives.

Composition and Origin of Component

The active ingredient in Микролют is Левоноргестрел (Levonorgestrel), a compound designated by its International Nonproprietary Name (INN). This component is a potent synthetic progestogen, a steroid derived from the natural hormone progesterone. Левоноргестрел is an entirely Synthetic compound, formulated for stability and reliable absorption via the Oral route. Микролют is manufactured as a Tablet, a solid dosage form where the active ingredient is combined with pharmaceutical excipients, such as Лактоза моногидрат (Lactose monohydrate).

General Purpose

The primary general purpose of taking Микролют is Contraception, or the sustained предотвращение беременности (prevention of pregnancy). This contraceptive function is achieved by using the consistent presence of the synthetic progestogen to induce specific physiological actions, chiefly the significant thickening of the cervical mucus and alteration of the uterine lining (endometrium). These mechanisms establish conditions that are unfavorable for fertilization and implantation, thereby fulfilling its role as a method of daily hormonal birth control.

Regulatory References

  1. Levonorgestrel: MedlinePlus Drug Information
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What side effects are possible with Микролют?

Possible side effects and safety information

The safety profile of Microlut (Levonorgestrel) is officially documented based on regulatory classifications, detailing expected adverse reactions and recognized safety constraints for this type of hormonal contraceptive.

Adverse Reactions by Frequency

Adverse reactions are classified by frequency as observed in regulatory documentation:

  • Very Common (Affecting 1 in 10 or more users): Alterations of menstrual bleeding patterns (including irregular bleeding, spotting, and infrequent periods), headache, ovarian cysts, and general discomfort such as nausea and fatigue.
  • Common (Affecting 1 in 100 to 1 in 10 users): Amenorrhea (absence of bleeding), mood changes (including depressed mood), decreased libido, weight increase, acne, and vulvovaginitis.
  • Uncommon/Rare: Reactions such as hyperpigmentation (chloasma), pruritus, urticaria, and rash are documented in official safety information at a lower incidence.

Serious Adverse Reactions and Safety Constraints

The official safety information highlights specific serious risks associated with hormonal contraceptive use:

  • Ectopic Pregnancy: If pregnancy occurs while using the Progestogen-Only Pill, it is associated with a higher likelihood of being an ectopic pregnancy.
  • Thromboembolic Events and Liver Tumours: The possibility of an increased risk of venous thromboembolism (blood clots) and rare reports of benign and malignant liver tumours are documented safety considerations for this class of medicine.
  • Contraindications for Special Populations: The medicine is explicitly contraindicated in individuals with Severe Hepatic Impairment until liver function has normalized and is not intended for use in postmenopausal women.
  • Time-Related Safety Notes: Changes in menstrual bleeding are most frequently reported during the initial months of treatment. The potential for chloasma (facial pigmentation) is noted with long-term exposure, particularly in susceptible women, requiring avoidance of sun exposure.
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Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory prescribing information indicates that an overdose of Levonorgestrel is generally classified as not likely to be life-threatening. Authorities have documented no reports of serious, deleterious effects following the acute ingestion of large doses of this progestogen-only preparation.

Documented Manifestations

The documented manifestations of overdose are typically non-severe. Anticipated clinical presentations include common gastrointestinal symptoms such as nausea and vomiting. Additionally, a likely hormonal effect is the subsequent occurrence of heavy vaginal bleeding, which is classified as a withdrawal symptom appearing several days after the overdose event. Other non-severe, transient symptoms that may accompany an overdose include headache, dizziness, breast tenderness, and fatigue.

Immediate Emergency Actions

Despite the low severity classification, regulatory authorities mandate specific emergency actions. If an overdose of Микролют is suspected, the official guidance requires the patient or caregiver to seek immediate medical attention. This includes calling a Poison Control Center or going directly to the Accident and Emergency Department at the nearest hospital. Management of a suspected overdose is restricted to providing symptomatic and supportive treatment, as no specific antidote is available for Levonorgestrel. Vital signs and other clinical markers will be monitored by a healthcare professional.

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Therapeutic Uses of Микролют

What Микролют treats: Main Uses and Benefits

The primary therapeutic role of this progestogen-only preparation is applied in addressing long-term pregnancy prevention. This contraception is commonly used as a primary method of fertility management.

The core indications involve addressing the chronic need for birth control and offering a suitable hormonal option when combined pills are medically unsuitable, such as during the postpartum and breastfeeding period. An additional benefit is the potential for easing specific menstrual cycle symptoms, including heavy menstrual flow (menorrhagia) and painful periods (dysmenorrhea).

“This medication supports patients in maintaining stability in family planning efforts and provides supportive relief when certain hormonal options may interfere with routine activities.”

This use supports patients in maintaining a sense of stability when symptoms are more noticeable.


Quick Fact: Relief for Menstrual Symptoms This type of hormonal management may assist with easing the burden of dysmenorrhea and heavy bleeding, contributing to a more manageable experience.

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Eligibility and Restrictions for Use

Who can and cannot use Микролют?

Eligibility for Микролют (Levonorgestrel Progestogen-Only Pill) is strictly determined by regulatory criteria, defining populations for whom use is permissible, restricted, or prohibited.

Contraindications (Must Not Use)

Use is absolutely contraindicated in women with known or suspected pregnancy, past or present severe hepatic disorders, and specific arterial or venous cardiovascular disorders (e.g., VTE, stroke, or myocardial infarction). The medicine must also be avoided by those with known or suspected sex hormone-dependent malignancies, undiagnosed vaginal bleeding, or hypersensitivity to the components.

Restricted and Non-Applicable Populations

Age-Related Rules: The medicine is not applicable for use before menarche or after menopause. Organ Function: Use has not been specifically investigated in patients with impaired renal function.

Conditional Use: While generally permitted during lactation, tablet intake must be specifically timed after feeding to minimize exposure to the infant. Women with risk factors for venous thromboembolism or certain rare hereditary sugar intolerances must also not use this medicine.

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What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile for Микролют is primarily defined by clinically significant pharmacokinetic interactions that alter the blood concentrations of the drug or co-administered substances, as documented by regulatory authorities.

Category Description / Identified Entities
Interacting Drug Categories Hepatic enzyme inducers (e.g., certain Anticonvulsants, Anti-tuberculosis medicines); HIV Protease Inhibitors; NNRTIs; Immunosuppressants; Herbal products
Specific Interacting Medicines Rifampicin, Efavirenz, Barbiturates, Phenytoin, Carbamazepine, Griseofulvin, Ciclosporin
Mechanistic Basis Hepatic enzyme induction (documented to decrease Levonorgestrel exposure); Inhibition of metabolism (documented to increase co-administered drug exposure)
Interaction-related Restrictions Co-administration with enzyme inducers may necessitate the use of an alternative or supplemental non-hormonal method, as documented in regulatory guidelines.

Official interaction statements:

  • Co-administration with enzyme-inducing medicines, such as the anti-tuberculosis medicine Rifampicin or Barbiturates, is documented to decrease the plasma concentration of Levonorgestrel and reduce its documented efficacy.
  • HIV Protease Inhibitors and NNRTIs are explicitly documented to potentially cause significant changes (increase or decrease) in the progestin's plasma levels.
  • Levonorgestrel may increase the risk of Ciclosporin toxicity by inhibiting its metabolism, a constraint noted in official regulatory sources.
  • The herbal product St. John's wort is consistently documented as an enzyme inducer that reduces the efficacy of progestin-only pills.

Connection to the overall interaction profile: The regulatory documents structure the interaction profile around clinically significant exposure modification. This classification mandates an awareness of potential efficacy reduction when co-administering with listed enzyme-inducing drugs. The profile further addresses risks associated with drug clearance changes, specifically the possibility of increased systemic levels of Ciclosporin, defining the necessary constraints for use.

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Mechanism of Action

How Микролют Works

Микролют's active component, levonorgestrel, exerts its action through multiple, complementary mechanisms by binding as an agonist to progesterone receptors in target tissues.

Peripheral Modulation: Receptor engagement in the cervix initiates a molecular cascade that drives a rapid and sustained increase in the viscosity and quantity of cervical mucus. This mechanism creates a physical barrier that impedes sperm motility and penetration, resulting in fewer sperm entering the upper reproductive tract. Additionally, levonorgestrel alters cell signaling and structure within the endometrium (uterine lining). This action causes the lining to become thin and atrophic, creating a physiological environment that is unfavorable for implantation.

Central Modulation: The constant presence of levonorgestrel influences the central Hypothalamic-Pituitary-Ovarian (HPO) axis. This action can dampen the pulsatile release of Luteinizing Hormone (LH), thereby interfering with the precise hormonal threshold required for a mature egg to be released (ovulation). This results in the modulation of activity within the targeted reproductive pathways.

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Dosage and Administration Information

How to Use Микролют

The administration of Микролют, a Progestogen-Only Pill containing 0.03 mg of Levonorgestrel, involves a specific method to ensure use. The route of administration is oral, requiring the tablet to be swallowed whole with liquid, and intake is independent of food.

The standard regimen dictates that one tablet is taken once daily. To maintain a consistent hormonal threshold, the tablet is administered at the same fixed time every 24 hours. This continuous dosing pattern involves consuming the entire pack and starting a new pack immediately thereafter with no tablet-free days.

Certain steps apply for managing lapses, as the efficacy of the 0.03 mg POP is time-sensitive. A specific missed-dose protocol is based on the delay: if the dose is missed by more than 3 hours (i.e., the interval exceeds 27 hours since the last dose), the last missed tablet is taken immediately and a barrier method of contraception is used for the subsequent seven days.

In terms of specific populations, this preparation is suitable for long-term use in women of childbearing potential, including those in the postpartum period and those who are breastfeeding. Adherence to the fixed-time administration is the primary procedural constraint of the regimen.

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Recent Clinical Evidence

Research evidence / Overview of studies for Микролют

This section provides an overview of the official research and clinical studies that examined the use of the Levonorgestrel Progestogen-Only Pill (POP), often referred to as a minipill. The summary focuses on the types of evidence available, what outcomes research explored, and what aspects of the medicine's use are still being studied or remain uncertain.

Evidence for Contraceptive Efficacy and Primary Use

Research has examined the core clinical evaluation of Микролют using Randomized Controlled Trials (RCTs) and systematic reviews, with the objective of monitoring the Accidental Pregnancy Rate (Pearl Index). Studies also tracked patient adherence and factors associated with method continuation. Evidence is limited for direct, head-to-head comparison across all Progestogen-Only Pills. Comparative data against combination oral contraceptives are also often lacking, and some contributing primary studies are considered older research.

Evidence Landscape for Postpartum and Breastfeeding Use

The preparation was evaluated in the context of postpartum women, particularly those who are breastfeeding. Studies, primarily systematic reviews and observational cohorts, monitored effects on the duration and rates of breastfeeding and measured infant health outcomes (e.g., growth). Findings indicate that the certainty of evidence across different infant outcomes can vary, and research provides limited insight into potential long-term, multi-year outcomes for exposed infants.

Research on Symptom Measures and Uncertainty

Research has explored the pill in the context of physical discomfort, such as heavy menstrual flow or painful periods. Studies examined measures like the Change in Menstrual Blood Loss (MBL) and change in dysmenorrhea (pain) scores. Evidence is generally limited for the use of the oral POP for the primary purpose of managing these severe symptoms; systematic reviews indicate low certainty. Additionally, comparative evidence is lacking between the various types of Progestogen-Only Pills, and long-term effects related to discontinuation and metabolic markers are not fully established due to limited follow-up durations in many controlled trials.

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Frequently Asked Questions (FAQ)

Common questions about Микролют (FAQ)

Q: Is Микролют used for anything other than contraception?

A: According to official product information, the primary and approved purpose of the medicine (Levonorgestrel 0.03 mg Progestogen-Only Pill) is the prevention of pregnancy (contraception).


Q: How does the single hormone in Микролют compare to the hormones in other common birth control pills?

A: Микролют is classified as a single-hormone contraceptive, containing only levonorgestrel (a progestogen). Many other common oral birth control pills contain two types of hormones: a progestogen and an estrogen component. This difference in composition is often cited as a reason this medicine may be appropriate for certain populations who cannot use estrogen-containing methods.


Q: How does the progestin-only formulation of Микролют affect the body compared to combination pills?

A: Progestogen-Only Pills (POPs) primarily affect the body by thickening cervical mucus and altering the uterine lining. While combination pills generally suppress the release of an egg (ovulation), regulatory documents indicate that POPs like levonorgestrel do not reliably stop ovulation in every cycle.


Q: How is the risk of venous thromboembolism (VTE) described for Микролют compared to combination oral contraceptives?

A: Official safety constraints recognize the possibility of an increased risk of blood clots (venous thromboembolism or VTE) with hormonal contraceptive use. However, regulatory guidance for Progestogen-Only Pills does not list age and smoking as contraindications, unlike combined pills. This difference reflects the classification of Progestogen-Only Pills relative to VTE risk factors.


Q: Is the risk of headaches associated with Микролют similar to other oral contraceptives?

A: Headaches are listed in regulatory documents as a Very Common adverse reaction, meaning they are experienced by many users (1 in 10 or more). Headaches are also frequently listed among the side effects for many other types of oral contraceptives. Official documentation summarizes the reported incidence specific to this medicine.


Q: Does taking antibiotics affect how Микролют is described as working?

A: Official interaction guidance indicates that most common antibiotics do not affect the documented efficacy of levonorgestrel-only pills. However, certain types of medicines known as enzyme-inducing antibiotics (such as rifampicin) are explicitly listed as decreasing the level of the drug in the blood, which can reduce its documented efficacy.


Q: How quickly is Микролют generally described as taking effect?

A: Official guidance specifies that if the pill is started after the first day of the menstrual cycle, additional contraceptive precautions must be used for the first seven days. This precaution is described to help ensure protection.


Q: Is it necessary to use a backup method when first starting Микролют?

A: Yes, regulatory recommendations state that if the first tablet is not started on the first day of the menstrual period, a barrier method should be used for the initial seven days. This precaution is described in official guidelines to support contraceptive protection.


Q: Is there official guidance on what to do if vomiting or diarrhea occurs after taking Микролют?

A: Official instructions state that if severe gastrointestinal issues like vomiting or diarrhea occur within 3 to 4 hours of taking the tablet, the absorption of the active ingredient may not be complete. This is treated as a missed dose, and official guidance indicates a replacement pill should be taken immediately.


Q: Can Микролют be taken by women who smoke (general population guidance)?

A: Regulatory documents for Progestogen-Only Pills (POPs) do not list smoking as a contraindication or warning. This is in contrast to combined oral contraceptives, where smoking is a key factor in determining suitability for use, particularly in women over 35.


Q: What is the general advice for switching from a combination pill to Микролют?

A: A person switching from a combined pill to a Progestogen-Only Pill should begin taking the first tablet of Микролют immediately after taking the last active tablet of their previous pill. This method is intended to avoid a hormone-free interval between the two medications.


Q: Does Микролют have any known impact on bone density according to research summaries?

A: Regulatory reviews note that the effects of Progestogen-Only Pills (POPs) on Bone Mineral Density (BMD) are not fully established. However, research summaries concerning levonorgestrel-based POPs have generally shown no adverse effect on BMD.


Q: Does grapefruit juice have any known interaction with Микролют?

A: Regulatory monographs document that grapefruit juice acts as a moderate inhibitor of the enzyme CYP3A4, which is involved in levonorgestrel metabolism. Because of this, consuming grapefruit juice may be associated with increased levels of the drug in the bloodstream.


Q: What is the shelf life of Микролют, and how should it be stored (basic factual information)?

A: In addition to storing the tablets below 30 C and in a cool, dry place, the official shelf life of the product is specifically stated in regulatory documents. This typically ranges from 3 to 5 years from the date of manufacture, provided the storage conditions are followed.


Q: Are there published data on the effectiveness rate of Микролют in clinical settings?

A: Yes, regulatory documents summarize clinical trials and report the contraceptive efficacy using the Pearl Index. This index is a standardized measure that tracks the number of accidental pregnancies per 100 woman-years of use for a specific method, providing an indication of effectiveness.


Q: How often do people report stopping Микролют due to side effects in studies?

A: Regulatory summaries of clinical trials include data on the rate of study discontinuation due to adverse events. These adverse events often include commonly reported issues like unacceptable bleeding changes or headaches, and the data reflects the frequency with which users stop the treatment in those studies.

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How should Микролют be stored and disposed of?

How to Store and Dispose of Microlut (Микролют)

Official regulatory guidelines strictly define the storage and disposal requirements for Microlut tablets to maintain product stability and ensure safety.


Storage Requirements

Condition Requirement
Temperature Store below 30°C (86°F).
Protection Keep in a cool, dry place, protected from heat and moisture.
Packaging Keep the tablets in the original blister pack until use.
Child Safety Must be kept out of the sight and reach of children.

Disposal Instructions

Any unused or expired Microlut must be disposed of in accordance with local regulations. It is officially advised not to dispose of the medicine via wastewater or household waste to prevent environmental contamination.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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