Microgest

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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.

Overview of Microgest

Property Description
Active Ingredient Progesterone (Micronized)
Form Softgel Capsule (Soft Gelatin Capsule)
Pharmacological Class Progestogen (Female Sex Hormone)
General Purpose Hormone Level Supplementation and Balance
Origin Natural (Chemically identical to human endogenous steroid)

Microgest: Definition and Pharmacological Class

Microgest is a pharmaceutical preparation containing the active ingredient Progesterone, which is scientifically classified as a Progestogen. Its active component is an endogenous steroid—a term signifying that its chemical structure is identical to the progesterone naturally produced by the human body. This single-component product is used to supplement or replace this vital hormone when a deficiency exists. Administering Micronized Progesterone is a recognized method to achieve the required hormonal effects.

Composition, Origin, and Dosage Form

The core component is Natural Micronized Progesterone, delivered via a Softgel Capsule. The term micronized refers to a specialized pharmaceutical process that reduces the progesterone particles to an extremely fine size. This processing enhances the dissolution and absorption of the drug, particularly when delivered orally. The active ingredient is derived from plant sources but is made chemically identical to the human hormone. The drug is formulated as a Soft Gelatin Capsule where the active substance is suspended in an oil vehicle, allowing for versatile administration.

General Purpose of Progesterone Supplementation

The overarching purpose of Microgest is to restore and maintain adequate Progesterone hormone levels to support essential hormonal balance. Progesterone functions by acting on the Progesterone receptor (PGR) in target tissues, such as the uterine lining (endometrium). This action is necessary to induce the maturation or secretory phase of the endometrium. By supplying the necessary endogenous steroid, Microgest provides a critical counterbalance to the effects of Estrogen, ensuring the controlled and stable development of hormone-sensitive tissues, which supports general reproductive physiology.

What side effects are possible with Microgest?

Possible Side Effects and Safety Information

This section outlines the officially documented adverse effects and safety characteristics of micronized progesterone (Microgest), based strictly on regulatory sources such as the FDA and EMA. It does not provide medical advice or instructions for use.

Officially Documented Adverse Reactions

Adverse effects are classified by frequency and System-Organ Class (SOC) in regulatory labeling:

System-Organ Class Frequency Official Adverse Reaction Listings
Nervous System/Psychiatric Very Common Dizziness, Drowsiness
Common Headache, Depression, Fatigue
Gastrointestinal Very Common Abdominal pain, Abdominal bloating
Common Nausea/vomiting, Diarrhea, Constipation
Reproductive System & Breast Common Breast pain or tenderness, Vaginal discharge, Altered periods

Serious Risks and Safety Restrictions

Regulatory documents include warnings about serious adverse risks, particularly when used in combination with estrogen as Hormone Replacement Therapy (HRT). These risks include an increased chance of Thromboembolic Events (such as Deep Vein Thrombosis, Pulmonary Embolism, and Stroke) and an increased risk of Invasive Breast Cancer.

Contraindications (Safety Restrictions): The medication is formally contraindicated (must not be used) in patients with Known Liver Dysfunction or Disease, a history of Thromboembolic Disease, Known or Suspected Breast Cancer, or Undiagnosed Abnormal Genital Bleeding.

Overdose and Emergency Response

Overdose and When to Seek Help

Information regarding overdose of Microgest (micronized progesterone) is based on reports and authoritative government regulatory documents.

Overdose symptoms are typically an extension of the drug's known effects and may present as non-severe Central Nervous System (CNS) effects.


Documented Overdose Presentations

Classification Manifestations and Management
Common Presentations Drowsiness (somnolence), dizziness, nausea, vomiting, or depressed mood.
Severe Outcomes Seizure, collapse, respiratory difficulty, or inability to be awakened.

Required Emergency Actions

Management of progesterone overdose is generally supportive and symptomatic, as no specific antidote is listed in official labeling. The drug should be discontinued immediately following overexposure.

Urgent medical attention is required:

  • Call Poison Control immediately for advice following any suspected overdose.
  • Call emergency services (e.g., 911) immediately if the individual experiences a seizure, collapses, has trouble breathing, or cannot be awakened.

Overdose risk may be heightened in individuals with severe hepatic impairment due to the liver's role in drug metabolism, a consideration noted in regulatory labeling.

Therapeutic Uses of Microgest

Microgest is relevant for easing symptoms across key areas of women's hormonal health where progesterone supplementation is appropriate to manage specific conditions and symptom patterns. It is commonly used to manage menopausal symptoms and to help with the absence of menses. The medication is commonly applied in contexts marked by increased discomfort or tension related to hormonal imbalance, which may offer supportive relief. Its primary uses include providing supportive endometrial protection when postmenopausal women receive estrogen therapy, contributing to the management of secondary amenorrhea (absent periods), and supporting the luteal phase during fertility procedures, such as IVF, or in situations requiring early pregnancy support. The primary therapeutic benefit is to provide support for the uterine lining, which may assist with managing the risk of abnormal thickening or hyperplasia of the uterine lining. It also may assist with managing disruptive menopausal symptoms such as hot flashes, night sweats, and mood instability. “This supportive therapeutic benefit helps maintain a sense of stability when symptoms are more noticeable, assisting with maintaining functional stability.”


Quick Fact: Relief for Hormonal Disruption (The medication supports women undergoing fertility procedures and those requiring hormone replacement therapy to assist with functional stability.)

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Eligibility Map: Who Can and Cannot Use Microgest — Official Regulatory Information

Eligibility Scope

Category Official Regulatory Status
Populations Allowed Adult women for secondary amenorrhea and endometrial protection during estrogen therapy. Indicated for specific uses in early pregnancy (e.g., ART support).
Contraindicated Populations Individuals with known hypersensitivity (including to excipients like peanut oil), active thromboembolic disease (DVT, PE, stroke), known liver dysfunction/severe hepatic impairment, undiagnosed abnormal vaginal bleeding, or a history of breast cancer.
Age-Related Rules Not indicated for pediatric use. Some formulations are not intended for women 65 and older.
Conditional Use (Caution) Patients with a history of depression, migraines, epilepsy, asthma, or conditions related to fluid retention (e.g., renal or heart disease) require close supervision.
Lactation Status Not indicated during breastfeeding.

Eligibility-Context Constraints

Official regulatory documents define non-eligibility based on:

Constraint Official Classification
Exclusionary Conditions Contraindicated (Absolute Exclusion)
Organ Function/Comorbidity Caution/Close Supervision (Conditional Use)
Demographic Status Not Established / Not Intended (Age/Gender Restriction)

Official Eligibility Statements

  • The medicine is contraindicated in women with severe hepatic impairment, history of breast cancer, or active vascular disease.
  • The medicine is indicated only for adult women for the approved conditions and for specific use in early pregnancy.
  • Close supervision is required for use in patients with conditions sensitive to fluid retention, or a history of neurological or mood disorders.

What should I know about interactions with other medicines?

Interactions with other medicines and products

This section outlines the officially documented interaction patterns for oral micronized progesterone, derived from authoritative government regulatory sources.


Pharmacokinetic and Metabolic Interactions

Co-administration with other medicines may alter the plasma concentrations of progesterone, mainly due to effects on the CYP3A4 enzyme responsible for its metabolism.

  • CYP3A4 Inhibitors: Substances such as Ketoconazole are strong inhibitors of this enzyme. Co-administration is formally documented to increase the bioavailability and systemic exposure of progesterone.
  • CYP3A4 Inducers: Strong inducers, including Rifampicin, Phenytoin, and Carbamazepine, may accelerate the metabolism of progesterone. This is anticipated to result in decreased progesterone plasma concentrations and altered exposure.

Food, Hormone, and Ingredient Constraints

  • Food: Concomitant ingestion of food is documented to increase the systemic exposure (AUC and C max) of the capsule relative to administration in a fasting state.
  • Conjugated Estrogens: Co-administration has been shown to increase the plasma concentrations of total estrone and equilin in the blood.
  • Ingredient-Based Contraindication: Due to the presence of peanut oil in the capsule formulation, the product is formally contraindicated in individuals with a known allergy to peanuts.
  • Severe Hepatic Disease: The use of oral micronized progesterone is contraindicated in patients with severe hepatic impairment, related to the drug's extensive liver metabolism.

Mechanism of Action

Microgest is a synthetic progesterone formulation that functions as an agonist for the nuclear progesterone receptors ( PR) PR-A and PR-B. Following absorption, the unbound hormone enters target cells, including those in the uterus and bone. Its primary mechanism begins with the ligand-induced activation of these nuclear PR receptors.

The binding of Microgest to PR leads to receptor activation and subsequent PR dimerization. This dimer complex translocates to the nucleus where it binds to specific DNA sequences, facilitating the transcription of target genes involved in cellular differentiation and control of cell growth.

This resulting gene expression modulates endometrial ER (estrogen receptor) expression and proliferation pathways within the uterine lining. Furthermore, in skeletal tissue, this action modulates the balance of osteoclast and osteoblast activity through PR-mediated signaling cascades that influence bone turnover.

Dosage and Administration Information

How to Use Microgest

Microgest (micronized progesterone) administration follows specific cyclic and sequential regimens.


Administration Scope

Entity Official Instruction
Route of Administration Primarily Oral administration via softgel capsule. Vaginal administration is an alternative for specific indications in some regions
Standard Dosing 200 mg once daily for endometrial protection (HRT) or 400 mg once daily for secondary amenorrhea.
Timing & Food The oral capsule is taken at bedtime and generally without food, as food significantly alters the absorption of the active ingredient.
Preparation The softgel capsule must be swallowed whole with water; it must not be crushed, chewed, or opened.

Regimen and Use Patterns

The usage of Microgest follows a cyclic, sequential regimen. For women receiving estrogen as part of Hormone Replacement Therapy (HRT), the typical use pattern involves taking the dose once daily for 12 continuous days during the last half of the 28-day cycle. For managing secondary amenorrhea (absent periods), the medicine is typically administered once daily for a fixed course of 10 days.

In terms of dose management, if a scheduled dose is missed, it should be taken as soon as possible. However, the missed dose must be skipped if it is near the time for the next scheduled dose, and doses must never be doubled. Dosing for older adults generally follows the same regimen as for younger adults, while use is not applicable to the pre-pubescent pediatric population.

This structured protocol defines the standardized approach to administering the medicine, ensuring adherence to established usage principles.

Recent Clinical Evidence

Research Evidence / Overview of Studies

This research overview details studies that investigated whether the drug may be associated with changes in patient outcomes, focusing on research examining the effect on symptoms.


Research Protocol and Early Trials

Studies explored the drug's hypothesized activity in relation to observed responses. Preclinical research examined the pharmacological profile and initial human safety data.


Phase 3 Efficacy Trials

Outcome Type Research Focus Key Findings Reported in Trials
Primary Outcome Effect on the primary symptom score. Trials reported on the changes observed in primary symptom scores.
Observed Response Timeline of symptom changes. Studies reported on the timeline of the observed changes in symptoms.
Secondary Endpoints Effect on pain and physical function. Focused on the measured changes in pain scores and function.

Combination Therapy Studies

Clinical studies have examined whether the combination is associated with quality of life. The studies compared this treatment to traditional therapies, and Phase 3 trials evaluated the study participants' experience of severe flares.


Study Scope and Follow-up

  • Study Population: The study population was defined in the trials to align with study protocols.
  • Long-Term Follow-up: Long-term use was evaluated for changes in symptom scores over time. The studies reported on the incidence of adverse events over a one-year follow-up period.

Frequently Asked Questions (FAQ)

Common questions about Microgest (FAQ)

Q: What is the purpose of taking Microgest during early pregnancy?

According to official product information, Microgest is indicated for specific uses in early pregnancy, such as providing support during the luteal phase of an Assisted Reproductive Technology (ART) cycle. Its purpose is to help maintain the pregnancy and may also be used to reduce the risk of spontaneous abortion (miscarriage) in certain patient groups.

Q: What are the differences between Microgest 100mg and 200mg?

The dosage strength prescribed depends entirely on the specific medical condition being addressed. For instance, 200 mg is often used in a cyclic regimen to provide endometrial protection during hormone replacement therapy. A healthcare provider typically determines the appropriate strength and regimen based on the patient’s specific needs and official guidelines.

Q: What should I do if I experience severe headaches while taking Microgest?

While headache is listed as a common adverse reaction in official documents, severe or persistent symptoms require attention. The official guidance suggests that a healthcare professional be consulted for evaluation if the headache is intense or persistent.

Q: Can I consume alcohol while taking Microgest?

Regulatory product warnings advise caution regarding the consumption of alcohol while using this medication. Regulatory information indicates that alcohol may interact with the medicine or increase the potential for certain side effects.

Q: Is Microgest affected by herbal supplements like St. John's Wort?

Official interaction sections indicate that some herbal supplements, such as St. John’s Wort, may affect the medication's intended function. These supplements can cause the body to break down the active ingredient faster, potentially reducing the concentration and effectiveness of the drug.

Q: Does Microgest interact with medicines used to treat anxiety or depression?

Official regulatory information indicates that progesterone may increase the level of certain central nervous system (CNS) depressant medications in the body. Furthermore, regulatory documents indicate that close supervision may be required for patients with a history of depression.

Q: What is the difference between oral and vaginal use of progesterone?

The oral and vaginal routes of administration are approved for different medical needs and conditions. Regulatory documents indicate that the chosen route affects the way the body absorbs the active ingredient and the resulting hormone levels in the blood.

Q: Is Microgest used for all types of hormone imbalances?

The drug is only formally indicated and approved for treating specific conditions where a progesterone deficiency or imbalance is present. These conditions primarily include secondary amenorrhea (absent periods) and providing endometrial protection during estrogen therapy.

Q: Is Microgest only for women who have gone through menopause?

No, the medication is not solely for women who have gone through menopause. Official product information states it is indicated for use in adult women for secondary amenorrhea (which affects pre-menopausal women) as well as for endometrial protection during post-menopausal estrogen therapy.

Q: Is Microgest considered a steroid?

The active ingredient in Microgest, progesterone, is chemically classified as an endogenous steroid. This term signifies that the drug's chemical structure is identical to the progesterone hormone naturally produced by the human body.

Q: Does Microgest affect blood pressure or diabetes management?

Regulatory warnings indicate that caution is advised for patients with certain pre-existing conditions, including high blood pressure and diabetes. Dosing adjustment for anti-diabetic medications may be necessary for patients initiating this treatment.

Q: Can Microgest cause weight gain or fluid retention?

Official documents indicate that fluid retention and edema (swelling) are among the effects that require caution or are listed in adverse reaction data. Fluid retention and edema are acknowledged, but weight gain is not universally listed as an independent adverse reaction.

Q: Does Microgest cause hair loss or thinning?

Official product labeling and adverse event summaries indicate that hair loss or thinning has been listed as a commonly reported adverse effect associated with the use of this medication.

Q: Does Microgest cause hot flashes to get better or worse?

Studies and official information indicate that oral micronized progesterone is associated with an improvement in vasomotor symptoms. The drug has been reported in clinical summaries as an effective treatment for hot flashes and night sweats.

Q: How is the liquid/oil inside the softgel capsule described?

The active ingredient is suspended within a liquid known as an oil vehicle inside the softgel capsule. Official documents identify this vehicle as Arachis oil (Peanut oil), along with other excipients like Soya Lecithin. This is why the medicine is contraindicated for individuals with a known peanut allergy.

How should Microgest be stored and disposed of?

The official storage and disposal guidelines for Microgest (progesterone capsules) ensure the medication remains effective and is handled safely at the end of its life.

Storage Conditions

Microgest must be stored at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F). The medication must be protected from freezing, excessive heat, and moisture. The capsules should be kept in the original container with the cap tightly closed and stored in a dry place. As with all medications, Microgest must be kept out of the reach and sight of children.

Disposal Instructions

Do not flush Microgest down the toilet or pour it into a drain. Unused or expired medication should be disposed of by taking it to a local drug take-back program. If a program is unavailable, consult a pharmacist or healthcare provider for instructions on proper disposal according to local regulations.

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

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