Algestona

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Algestona

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Algestona

What is Algestona?

Algestona (also known as algestone) is a synthetic medication belonging to the class of progestins. It is a derivative of progesterone, a naturally occurring hormone in the human body that plays a central role in the regulation of the reproductive system.

Classification and Action

As a progestogen, algestona mimics some of the biological effects of natural progesterone. Its primary function involves interacting with progesterone receptors in various tissues. In the context of reproductive health, it is most commonly utilized for its ability to influence the lining of the uterus and manage hormonal balances.

Common Uses

Algestona is rarely used as a standalone medication. Instead, it is typically formulated in combination with an estrogen component. These combinations are primarily used for:

  • Hormonal Contraception: It works alongside estrogen to prevent ovulation and alter cervical mucus to prevent pregnancy.
  • Menstrual Cycle Regulation: It can be used to treat certain irregularities in the menstrual cycle by providing a predictable hormonal pattern.

Chemical Variations

In clinical applications, the medication is often found in the form of an ester, such as algestona acetophenide. This specific formulation is designed to be long-acting, allowing the medication to be released slowly into the bloodstream over an extended period. This characteristic makes it suitable for injectable contraceptive methods that provide protection for several weeks at a time.

Regulatory References

  1. NIH MeSH Data
  2. FDA UNII Data

What side effects are possible with Algestona?

Possible Side Effects and Safety Information

The safety profile for Algestona, a Combined Hormonal Contraceptive (CHC), is officially structured to classify adverse reactions based on frequency, system-organ class, and severity. This information reflects data documented in authoritative government regulatory sources.

Official Adverse Reactions and Classification

Adverse effects are categorized by their expected occurrence, with classifications such as Common and Rare defining the risk profile. Common reactions generally include changes in bleeding patterns (such as spotting or amenorrhea), headache, nausea, and breast discomfort. These effects are classified within several System-Organ Classes, including Reproductive System and Breast Disorders, Nervous System Disorders, and Gastrointestinal Disorders.

Serious Adverse Reactions and Safety Constraints

Regulatory documents mandate specific attention to Serious Adverse Reactions, which, while rare, are clinically significant. These include an increased risk of Thromboembolic Events, such as Deep Vein Thrombosis, Pulmonary Embolism, and Stroke, as well as the risk of Hepatic Tumors (liver tumors).

Safety-related limitations are explicitly defined. For example, the highest risk warning applies to Smokers over age 35 regarding serious cardiovascular events. Furthermore, use is generally restricted (contraindicated) in individuals with a history of or current thromboembolic disease, severe uncontrolled hypertension, or severe hepatic impairment. Officially documented safety patterns also note that the risk of thromboembolism is highest during the first year of use of a combined hormonal contraceptive.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for an overdose of Algestona, a combined hormonal contraceptive, indicates a generally low level of acute systemic toxicity. Overexposure to the hormonal components is not expected to be life-threatening or cause severe long-term health effects in most individuals.

Documented Overdose Presentations

The clinical manifestations described in regulatory documents primarily involve the gastrointestinal and reproductive systems. These commonly include nausea and vomiting. A key physical sign of overexposure is the occurrence of vaginal bleeding, which may present as heavy withdrawal bleeding or spotting. Regulatory guidance notes that overdose in female children, particularly those who have not yet reached menarche, may result in the manifestation of withdrawal bleeding.

Emergency Action and Management

In cases of known or suspected overdose, the official regulatory mandate is to seek immediate medical attention and contact a Poison Control Center for specialized guidance. Management of the overdose is strictly restricted to symptomatic and supportive treatment. No specific antidote for the hormonal components (Algestone Acetophenide and Estradiol) is documented in official prescribing information. Close observation and monitoring of vital signs are required as part of professional medical care.

Therapeutic Uses of Algestona

Quick Facts: Uses of Algestona

  • Support for Pregnancy Prevention: May be used in combination regimens to help prevent conception.
  • Management of Acne: May be applied topically to address aspects of acne.
  • Regulation of the Menstrual Cycle: Utilized in specific contexts to influence the natural menstrual cycle.

What Algestona Treats: Main Uses and Benefits

Algestona (Algestone acetophenide, or DHPA) is a synthetic progestin that has established therapeutic applications, primarily when administered in combination with an estrogenic agent. The primary clinical area for this combination is in hormonal contraception. It is utilized as a monthly injectable preparation to offer support for pregnancy prevention.

In addition to its role in reproductive health, Algestona has also demonstrated utility in specific dermatological applications. When formulated for topical use, it may be indicated for the local management of acne. This approach is intended to provide a measure of benefit for individuals managing this skin condition. The compound's effect as a progestin enables its use in regulated medical settings to help modify and influence the natural course of the menstrual cycle.

Regulatory References

  1. NIH MedlinePlus guidance on progestins

Eligibility and Restrictions for Use

Algestona, a Combined Injectable Contraceptive, is strictly governed by the official eligibility criteria established for all combined hormonal products, focusing on preventing use in high-risk populations. The medicine is authorized for women of reproductive age who do not present any absolute contraindications.


Category Eligibility Classification
Contraindicated Populations Women with a history of thromboembolic disorders (e.g., DVT, PE, stroke, MI), known or suspected pregnancy, known or suspected breast malignancy, or women over 35 years of age who smoke
Condition-Specific Rules Contraindicated in patients with significant liver disease (including liver tumors or active hepatitis) and undiagnosed abnormal uterine bleeding.
Restricted Use Populations Not recommended for fully breastfeeding women in the early postpartum period. Use should be stopped before major surgery or during prolonged immobilization.
Age-Related Eligibility Primary use is for adult women. Safety is not established in pre-pubertal children, and the medicine is not indicated for postmenopausal women.

Official regulatory documents define these contraindications and restrictions to limit use to a population that can safely receive this class of medication, creating a clear, label-defined boundary for eligibility.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Algestona (also known as Algestone, a synthetic progestin) has the potential to interact with various classes of medicines, primarily by affecting its metabolism in the body or by interfering with the action of co-administered drugs. These interactions may result in decreased effectiveness of Algestona or altered effects of the other medication.

Key Interaction Categories

Interacting Product Category Potential Effect of Interaction Mechanistic Basis (Inferred)
Enzyme Inducers (e.g., certain anticonvulsants, antibiotics) Decreased serum concentration of Algestona Increased hepatic metabolism (CYP450 enzyme induction)
Antibiotics (e.g., Penicillins, Tetracyclines) Decreased effectiveness of Algestona Alteration of the gut flora, affecting progestin recirculation
Antidiabetic Agents (e.g., Insulin, Sulfonylureas) Decreased therapeutic effect of antidiabetic agent Algestona, as a progestin, may impair glucose tolerance
Anticoagulants (e.g., Warfarin, Dabigatran) Decreased therapeutic effect of anticoagulant Interference with blood coagulation factors/mechanisms

Important Considerations

Patients using medications known to induce hepatic enzymes, such as carbamazepine, phenytoin, and rifampicin, may experience a significant reduction in Algestona's circulating levels. This requires close monitoring. Similarly, the simultaneous use of broad-spectrum antibiotics, which may reduce the reabsorption of progestins, can lead to decreased therapeutic efficacy. The effect on blood glucose regulation warrants caution when Algestona is used in patients taking diabetes medication. Combining Algestona with anticoagulants may reduce the desired blood-thinning effects.

Mechanism of Action

Algestona functions as a synthetic progestin, exerting its pharmacological activity primarily through agonist binding to the intracellular progesterone receptor (PR). Upon entering a target cell, Algestona traverses the membrane and binds to the cytosolic PR, leading to a conformational change and dissociation from heat shock proteins. This activated receptor-ligand complex then translocates to the cell nucleus, where it acts as a ligand-dependent transcription factor. The complex binds to specific DNA sequences known as Progesterone Response Elements (PREs) located in the promoter regions of target genes.

This binding event modulates gene transcription, either activating or repressing the expression of PR-regulated genes. Key intracellular consequences include the alteration of mRNA levels for proteins involved in cell proliferation, differentiation, and tissue maintenance. System-level physiological consequences involve the modulation of the hypothalamic-pituitary-ovarian axis via negative feedback, which alters the pulsatile release of gonadotropin-releasing hormone (GnRH) and consequently inhibits pituitary secretion of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH). This systemic action results in the inhibition of ovulation and endometrial secretory transformation.

Dosage and Administration Information

Algestona is a pharmaceutical preparation intended for use as a long-term combined hormonal contraceptive. Its administration adheres to a highly specific, cyclical protocol based on its formulation as an oil-based solution for injection.


Administration Protocol

The officially approved route of administration is exclusively by deep intramuscular (IM) injection. This requires the medicine to be administered into the muscle, typically the gluteal or deltoid areas. The medication is supplied as a ready-to-inject solution and does not require any dilution or preparation before use.


Standard Labeled Regimen

Dosing Schedule: The standard adult regimen for this contraceptive is based on a fixed unit dose per cycle, most commonly containing 150 mg of Algestone Acetophenide combined with 10 mg of an estradiol component (such as Estradiol Enanthate).

Timing and Frequency: The administration schedule mandates an injection once per month. The initiation of the regimen requires the first injection to be administered between Day 1 and Day 5 of the menstrual cycle. To maintain sustained therapeutic levels, subsequent injections must be precisely scheduled within a narrow window of 30 pm 3 days from the previous dose. Strict adherence to this monthly interval is the governing procedural constraint for the long-term use of this contraceptive method.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Algestona

This section provides a factual, non-advisory overview of the research base for the Algestona combination (Algestone Acetophenide and Estradiol), focusing on the types of studies conducted and what outcomes were measured by researchers, without making any clinical recommendations.


Evidence for Use as a Monthly Injectable Contraceptive

Research has primarily focused on the use of Algestona as a Combined Injectable Contraceptive (CIC), where it was studied for the prevention of pregnancy. Researchers conducted Randomized Controlled Trials (RCTs) and various clinical efficacy trials, complemented by large-scale observational studies. The main outcomes that research examined included how frequently pregnancies occurred in the observed populations, a measure known as the Pearl Index, and patient adherence or continuation rates.

The data gathered across these studies show patterns related to contraceptive performance when use was observed. The trials described patterns related to preventing conception during the observed treatment intervals. Furthermore, studies monitored the time it took for the ability to conceive to return after discontinuation. Findings describe patterns observed in the studies regarding the return of ovulation within several months in the observed populations.


Evidence on Menstrual Cycle Regulation and Secondary Uses

The effects of this combined hormonal formulation on a user's cycle was studied for outcomes related to systemic or functional imbalance. Researchers tracked patterns of menstrual bleeding and cycle control, including the occurrence of spotting, irregular bleeding, and amenorrhea (absence of bleeding) in women using the injectable. Studies reported how symptoms evolved in the observed populations concerning patterns of menstrual bleeding compared to natural cycles, with some participants experiencing increased spotting or irregular bleeding.

What remains uncertain for this area is that the comparative evidence is lacking for how the combined injectable specifically controls bleeding compared to other newer hormonal formulations. The research also examined the use of Algestona compounds in settings involving certain dermatological conditions, particularly acne. This evidence base evidence is limited, composed mainly of older clinical studies and review literature that focused on the general effects of hormonal treatments for skin issues.

Frequently Asked Questions (FAQ)

Common questions about Algestona (FAQ)

Q: Is Algestona the same type of medicine as [similar drug name]? What's the difference?

Official information classifies Algestona as a Combined Hormonal Contraceptive (CHC). The product contains two specific synthetic components, a progestin called Algestone Acetophenide and an estrogen. Other contraceptive products may differ by using alternative progestin or estrogen compounds to achieve their effects.

Q: Are there any common foods or drinks that official sources say interact with Algestona?

Regulatory documents mention the potential for interactions with certain foods or drinks, such as grapefruit or grapefruit juice, which may affect drug metabolism. This information is included in the interaction warnings for this drug class.

Q: Does Algestona interact with common over-the-counter pain relievers?

Product information for this drug class notes that some common over-the-counter medications, particularly non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen, have the potential to affect the body's metabolism of the hormone components. This potential for interaction is why they are often discussed in official documents.

Q: What happens if Algestona is taken at the same time as alcohol, according to official warnings?

Official regulatory warnings note the potential for ethanol (alcohol) to increase the central nervous system effects and blood levels of some components of hormonal contraceptives. This potential interaction is noted in regulatory documents and is why caution is mentioned.

Q: Is it true that Algestona can affect sleep patterns?

Official drug labels for hormonal contraceptives, including Algestona, sometimes list effects categorized under Nervous System Disorders. These common side effects, such as headache or drowsiness, may indirectly influence sleep patterns in some users.

Q: What is the official information regarding weight changes while taking Algestona?

Official data from clinical efficacy trials conducted with this combined injectable contraceptive combination observed a small mean increase in weight over the first 12 cycles of use in the studied populations. This is noted as a possible finding in the adverse events profile.

Q: How quickly can someone expect to see the typical effects of Algestona?

According to the administration protocol, contraceptive protection is typically established immediately if the first injection is administered as directed (between Day 1 and Day 5 of the cycle). If administered outside of this specific window, official guidelines recommend using a backup contraceptive method for a specified short duration.

Q: How long do most people stay on Algestona for the described treatment purposes?

The approved regimen describes this product as a long-term combined hormonal contraceptive method intended for sustained use. Official documents do not typically specify a maximum duration for use as long as the patient remains eligible and does not develop a contraindication.

Q: What does 'contraindication' mean in the context of Algestona?

In regulatory documents, a contraindication is defined as a condition or factor that absolutely prohibits a medical treatment. This is because the potential harm associated with using Algestona under that specific condition is considered to outweigh any potential benefit.

Q: Why is Algestona sometimes prescribed to be taken only for a short time?

Official product restrictions state that use of this class of medication must be stopped before major surgery or during prolonged periods of immobilization. This temporary cessation is required to manage the heightened risk of thromboembolic events associated with these situations.

Q: Are there any known long-term effects of taking Algestona described in official literature?

Official regulatory documents detail that the risk of serious events like thromboembolism associated with combined hormonal contraceptives is highest during the first year of use. Long-term use, beyond the first year, is described in regulatory documents as needing continued assessment of patient eligibility and safety.

Q: What happens if I miss a dose of Algestona, generally speaking?

The official dosing schedule mandates strict adherence to the monthly timing. If a subsequent injection is delayed beyond the specified narrow monthly window, the possibility of pregnancy increases. Official patient information describes scenarios where a pregnancy test and a backup contraceptive method may be relevant.

Q: Is Algestona considered a high-risk medication by regulatory bodies?

Regulatory bodies apply a significant level of warning to this class of medication due to potential serious risks. This includes a Black Box Warning for specific populations, such as smokers over age 35, regarding the increased risk of severe thromboembolic events.

Q: What is the risk of dependence or addiction described for Algestona?

Official regulatory information for combined hormonal contraceptives, including the components of Algestona, does not classify this medication as having a risk of dependence or addiction.

Q: Does taking Algestona require any special monitoring or lab tests?

Regulatory documents indicate that patient monitoring is necessary both before and during use. This may involve regular checks of blood pressure and assessment for risk factors, and may include specific laboratory tests to rule out contraindications such as hepatic impairment.

Q: What have clinical studies shown about Algestona's effectiveness for its approved uses?

Clinical efficacy trials conducted with this injectable combination have examined its performance for the prevention of pregnancy. Researchers measured the occurrence of pregnancies in the observed populations, an outcome quantified by the Pearl Index, when the medication was used exactly as directed.

Q: Do regulatory bodies classify Algestona as a controlled substance?

Official drug classification systems do not classify the hormonal components of this combined injectable contraceptive (synthetic progestin and estrogen) as a controlled substance under government regulations.

Q: Can Algestona affect the results of common medical tests?

As a hormonal contraceptive, Algestona may influence the results of some laboratory tests. Official documentation advises that this may include tests measuring factors such as blood coagulation, lipid profiles, or glucose tolerance.

Q: Why does Algestona have a specific warning about [a specific organ, e.g., liver]? What does that mean?

The warning regarding the liver is due to the potential for rare serious adverse reactions, specifically an increased risk of Hepatic Tumors (liver tumors). For this reason, the drug is also contraindicated (absolutely forbidden) in patients with significant existing liver disease.

Q: Why do official documents mention that Algestona is not for long-term use?

This is a common misunderstanding. Official documents describe Algestona as a long-term combined hormonal contraceptive intended for sustained use. There is no official regulatory statement that the medicine is not for long-term use.

Q: Are there any known interactions between Algestona and herbal supplements?

Official drug labels for combined hormonal contraceptives note that some herbal products, particularly those known to affect liver enzymes (such as St. John’s Wort), have the potential to reduce contraceptive effectiveness. This information is included in the interaction warnings.

Q: Are there official restrictions on driving or operating machinery while on Algestona?

Official documents note that if a user experiences side effects that may affect concentration or motor skills, such as dizziness or headache, exercising caution before driving or operating machinery is described as appropriate.

Q: What should I do if I notice a side effect mentioned in the official guide?

The patient information provided by regulatory agencies describes that individuals experiencing side effects should contact a healthcare provider to discuss symptoms and ensure appropriate management.

Q: What specific patient monitoring is required before starting Algestona?

Before administration, a healthcare provider typically conducts a complete medical history. This process includes assessing risk factors, checking blood pressure, and may involve necessary laboratory tests to rule out contraindications related to conditions like liver or thromboembolic disease.

Q: What does the patient information leaflet say about overdose symptoms for Algestona?

Patient information for hormonal contraceptives often describes symptoms observed in cases of overdose of the hormonal components. These effects may include non-serious reactions such as nausea, vomiting, breast tenderness, or excessive vaginal bleeding.

Q: How is the safety profile of Algestona described in its Summary of Product Characteristics (SmPC)?

The Summary of Product Characteristics (SmPC) is an official regulatory document that describes the safety profile as a detailed list of adverse drug reactions. These are systematically classified by the body system they affect and their expected frequency, along with mandatory warnings on serious adverse reactions.

Q: What do official sources say about taking Algestona with or without food?

Regulatory information specifies that Algestona is a solution for deep intramuscular (IM) injection into the muscle. Since it is not taken by mouth, food or drink intake is irrelevant to its use or effectiveness.

Q: Why might a patient need to stop taking Algestona suddenly?

Official documents mandate the use of Algestona be stopped immediately if a new contraindication arises, such as a confirmed thromboembolic event. It is also stopped before periods of prolonged immobilization or major surgery.

Q: How is Algestona packaged, and what information is on the label?

Algestona is supplied as a ready-to-inject solution in a primary container, such as a vial or ampoule. The label is required to clearly bear the product name, concentration, and the official route of administration (IM injection).

Q: Why is timing important when taking Algestona?

Precise timing, within the narrow monthly window, is important because it is required to maintain sustained therapeutic levels of the hormones throughout the cycle. This ensures the continuous inhibition of ovulation and endometrial transformation necessary for reliable contraception.

Q: Is Algestona available without a prescription in other countries, and what are the rules?

The legal status of Algestona in general is prescription only ( Rx) due to the nature of the hormonal components and the potential for serious risks requiring medical supervision. Official regulatory texts do not cover the specific dispensing rules of foreign jurisdictions.

Q: Are there different names for Algestona in different countries?

Yes, the specific combination of Algestone Acetophenide and Estradiol Enanthate is marketed under various commercial brand names globally. These alternative names may include products such as Perlutal, Topasel, and Agurin in different regions.

How should Algestona be stored and disposed of?

How to Store and Dispose of Algestona

Official regulatory guidelines dictate specific requirements for storing, protecting, and disposing of Algestona to maintain its stability and ensure environmental safety.

Storage and Stability

Requirement Official Statement Basis
Temperature Must be stored below a specified temperature (e.g., 25 C or 30 C), as defined by stability data.
Protection Must be kept in the original container to protect the medicine from light and moisture.
Handling Any explicit prohibitions, such as Do not freeze or Do not refrigerate, must be strictly followed.
Child Safety Keep this medicine out of the sight and reach of children.
In-Use If opened or prepared, a strict in-use stability period and specific storage conditions apply.

Disposal Instructions

Official instructions prohibit the disposal of Algestona via household trash or flushing it down a toilet or drain. Unused or expired medication must be returned to a designated pharmacy take-back program or collection point. Disposal must be carried out according to local regulations to ensure pharmaceutical waste is managed properly and to protect the environment.

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

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