Fisterid

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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 Fisterid

Quick Facts

Property Description
Active ingredient Finasteride
Form Film-coated Oral Tablets
Pharmacological class 5-alpha reductase inhibitor (5ARI)
General purpose Hormonal activity modulation (DHT reduction)
Origin Synthetic 4-azasteroid compound

What Type of Medicine is Fisterid?

Fisterid is a specialized, synthetic prescription medicine defined by its active component, Finasteride, which belongs to the distinct pharmacological class of 5-alpha reductase inhibitors (5ARIs). This classification identifies it as a compound engineered to selectively interrupt a specific biochemical process within the body, a principle clinically recognized for its efficacy in hormonal modulation. Structurally, Finasteride is classified as an azasteroid, a synthetic derivative of the natural steroid structure. The medication is designed for systemic effect via oral administration and is consistently presented as a film-coated oral tablet, a stable dosage form that facilitates accurate, predictable absorption throughout the body. Finasteride functions as an inhibitor of the enzyme 5-alpha reductase.

As a single-active ingredient product, or monotherapy, Fisterid operates by specifically targeting the Type II enzyme, making it a foundationally important agent in the management of conditions sensitive to hormonal influence in adult males. This compound acts as a specific Type II 5-alpha reductase inhibitor, a specificity that ensures the drug primarily focuses on the most potent form of the enzyme.

Finasteride: Composition and Its General Purpose

The core of Fisterid’s composition is Finasteride, the active ingredient that functions as a potent and specific enzyme inhibitor. The primary function of Finasteride is achieved by blocking the action of the enzyme 5-alpha reductase, which is naturally tasked with converting testosterone into the highly potent dihydrotestosterone (DHT). By achieving a targeted and sustained reduction of DHT concentration in sensitive tissues, the medication’s fundamental benefit is the suppression of biological effects driven by this hormone. This action establishes Fisterid as a key systemic treatment for issues linked to excessive DHT influence, allowing it to address the underlying cause of abnormal tissue development in adult males.

Regulatory References

  1. Finasteride - StatPearls - NCBI Bookshelf

What side effects are possible with Fisterid?

Possible Side Effects and Safety Information

Finasteride, the active ingredient in Fisterid, has a safety profile characterized by adverse reactions primarily affecting the reproductive and psychiatric systems, as documented in regulatory labeling. Safety information is classified by frequency based on clinical data and post-marketing reports, including categories such as Common, Uncommon, and Not Known.

Documented Adverse Reactions

Classification System-Organ Class Examples of Documented Effects
Common Reproductive system Decreased libido, Erectile dysfunction, Ejaculation disorder (including decreased volume)
Uncommon Reproductive, Psychiatric Gynecomastia (breast enlargement), Breast tenderness, Depressed mood, Depression
Not Known Psychiatric, Immune system Anxiety, Testicular pain, Male infertility, Hypersensitivity reactions (including angioedema)

Serious Adverse Reactions and Safety Patterns

The regulatory profile documents reports of Male Breast Cancer in the post-marketing setting. Data also indicate an association with an increased risk of High-Grade Prostate Cancer (Gleason Score 8–10). Sexual adverse effects are often noted to appear early in treatment and may resolve with continued use; however, cases of sexual dysfunction persisting after stopping the medication have been reported.

Population-Specific Safety Constraints

Fisterid is contraindicated for use in women who are or may be pregnant due to the potential risk to a male fetus. Similarly, it is not indicated for use in the pediatric population. The medicine requires an essential adjustment for laboratory testing: Finasteride causes an approximate 50% decrease in serum Prostate-Specific Antigen (PSA) values, and this must be accounted for in the interpretation of results.

Overdose and Emergency Response

The official regulatory documentation on finasteride overdose is primarily structured around observations from clinical trials. Patients who received single oral doses up to 400 mg, as well as those who received multiple doses up to 80 mg daily for three months, demonstrated a high tolerance, as no adverse clinical effects were observed in these patient groups. Consequently, the official labeling does not define a specific symptom profile or a set of physiological manifestations associated with high-dose ingestion.

In the event of any suspected or accidental overdose, the standing regulatory guidance requires that immediate medical attention be sought. The official prescribing information explicitly states that until further clinical experience is obtained, no specific treatment or antidote is recommended for a finasteride overdose; management is expected to be symptomatic and supportive.

Urgent medical services must be contacted immediately if the individual exhibits signs of severe systemic distress. It is mandated to seek emergency help if the person has collapsed, experienced a seizure, is having trouble breathing, or cannot be awakened. For all other cases of suspected overdose, prompt contact with a certified Poison Control center or medical consultation is necessary.

Therapeutic Uses of Fisterid

Main Uses and Benefits of Fisterid

Fisterid is a medication primarily utilized for the management of specific conditions related to hormonal activity in the body. It belongs to a class of medications known as 5-alpha reductase inhibitors. Its primary function is to block the conversion of testosterone into dihydrotestosterone (DHT), a hormone that plays a key role in the development of certain conditions.

Benign Prostatic Hyperplasia (BPH)

Fisterid is frequently prescribed to treat benign prostatic hyperplasia, a non-cancerous enlargement of the prostate gland. This condition is common in aging men and can cause significant discomfort by pressing against the urethra.

  • Reduction of Prostate Size: By lowering DHT levels, the medication helps to gradually shrink the enlarged prostate gland.
  • Improvement of Urinary Symptoms: As the prostate size decreases, pressure on the urethra is relieved. This often leads to better urine flow, reduced straining, and a decrease in the sensation of incomplete bladder emptying.
  • Decreased Frequency and Urgency: Patients may experience a reduction in the need to urinate frequently, particularly during the night.
  • Risk Mitigation: Long-term use of the medication may reduce the risk of acute urinary retention and the eventual need for prostate-related surgery.

Male Pattern Hair Loss (Androgenetic Alopecia)

In addition to its use for prostate health, Fisterid is used to treat androgenetic alopecia, commonly known as male pattern hair loss. This condition is characterized by a thinning of the hair on the scalp, often following a specific pattern.

  • Stabilization of Hair Loss: The medication works by lowering scalp levels of DHT, which is the hormone responsible for the shrinking of hair follicles. This can help slow down or stop further hair loss in many individuals.
  • Promotion of Regrowth: While not effective for everyone, some men experience an increase in hair count and improved hair coverage in thinning areas over time.
  • Maintenance of Hair Quality: The treatment may help maintain the thickness and health of existing hair by preventing the miniaturization of hair follicles.

Eligibility and Restrictions for Use

Who Can and Cannot Use Fisterid?

Fisterid (Finasteride) eligibility is strictly defined by regulatory authorities and is restricted to adult males (18 years and older). Official labeling establishes clear prohibitions and conditions for use.


Populations Prohibited from Use

Fisterid is contraindicated and must not be used by the following groups:

  • Females: The medicine is not indicated for use in women.
  • Pregnant or Potentially Pregnant Females: Use is absolutely contraindicated due to the severe risk of causing abnormalities of the external genitalia of a male fetus.
  • Pediatric Patients: Use is contraindicated in children and adolescents under 18 years, as safety and efficacy have not been established.
  • Hypersensitivity: Patients with known allergy or hypersensitivity to Finasteride or any excipient.

Condition-Specific Eligibility

Condition Regulatory Status
Hereditary Metabolic Disorders Contraindicated due to the presence of lactose (e.g., total lactase deficiency).
Renal Impairment No dosage adjustment is necessary for patients with kidney function issues.
Hepatic Impairment Use with caution is advised in patients with liver function abnormalities.

Handling Restriction: Pregnant women or women who may become pregnant must not handle crushed or broken Fisterid tablets due to the potential for absorption through the skin.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Fisterid (Finasteride) is defined by the conclusion that no drug interactions of clinical importance have been identified with commonly co-administered medicines. The following table summarizes the official findings from government drug labels regarding interaction potential:

Interaction Focus Official Regulatory Statement
Metabolic Pathway No effect on the Cytochrome P450-linked drug metabolizing enzyme system.
Tested Medicines No clinically meaningful interactions were found with compounds tested in man, including digoxin, propranolol, theophylline, and warfarin.
Food & Timing Bioavailability is not affected by food, meaning no mandatory timing separation rules exist for meals.

Interaction Classification

Official drug labels classify the interaction potential as low, stating that no contraindicated combinations are listed for co-administration.

Official Interaction Statements

  • Fisterid does not appear to affect the CYP450 enzyme system, minimizing the potential for drug exposure alteration based on this common metabolic pathway.
  • The medicine was used in clinical studies with major drug classes, including alpha-blockers and ACE inhibitors, without evidence of clinically significant adverse interactions.
  • Regarding specialized populations, the regulatory label notes that the effect of hepatic insufficiency on Finasteride clearance has not been studied, and caution is noted due to extensive liver metabolism.

Connection to the overall interaction profile

The regulatory documents establish a clear interaction structure based on the explicit finding that clinically important interactions were not observed with tested medicines or major concomitant drug classes, signifying a low overall propensity for drug-drug interactions.

Mechanism of Action

Fisterid is classified as a 5alpha-reductase inhibitor. Its primary molecular target is the Type II 5alpha-reductase isoenzyme, an intracellular, nuclear-bound enzyme primarily expressed in tissues such as the prostate, seminal vesicles, epididymides, and hair follicles. The drug functions as a competitive inhibitor of this enzyme, forming a stable complex that physically impedes the catalytic conversion of the androgen testosterone into its more potent metabolite, dihydrotestosterone (DHT).

This molecular interaction leads to a significant reduction in both serum and tissue-specific concentrations of DHT. The intracellular consequence of reduced DHT is a decrease in the activation of androgen receptors within the target cells. Since DHT is a key mediator of growth and cellular proliferation in androgen-sensitive tissues, the downstream effect is a modulation of cell signaling that favors atrophy and reduced tissue volume in organs where Type II 5alpha-reductase is highly active. This systemic modulation results in reduced overall DHT levels.

Dosage and Administration Information

Instruction Map: How to use Fisterid — Official Administration Guidelines

Fisterid is intended for oral administration as a film-coated tablet, and its usage is defined by fixed dosing protocols based on the condition being addressed.


Administration Scope

Instruction Entity Official Guideline
Route of administration Oral administration only.
Dosing schedule One 5 mg tablet once daily for benign prostatic hyperplasia (BPH); One 1 mg tablet once daily for androgenetic alopecia.
Timing in relation to meals (if applicable) May be administered with or without meals, but should be taken consistently at the same time each day.
Preparation requirements (if applicable) The tablet must be swallowed whole and should not be crushed or broken.
Age-group administration rules Older Adults: No dosage adjustment is necessary. Pediatrics: Use is not indicated.
Missed-dose rules If a dose is missed, skip the forgotten dose and continue with the next scheduled dose; do not double the dose.
Special procedural conditions The full therapeutic effect for either use often requires three to six months of continuous daily administration before the benefit can be properly assessed.

Instruction Classifications (High-Level)

Classification Entity Official Use Pattern
Administration method type Oral (solid dosage form)
Frequency pattern Once daily (q.d.)
Guideline consistency Consistent across standard prescribing information
Use-context constraints Long-term daily adherence is required to sustain the effect; no dose adjustment is necessary for patients with renal impairment.

Resulting Procedural Structure

Official step sequence:

  • Take the specified 1 mg or 5 mg film-coated Fisterid tablet.
  • Swallow the dose whole with fluid.
  • Administer the dose once per day at a regular time.

Connection to the overall use protocol: The official administration protocol establishes a standardized once-daily oral regimen requiring that the film-coated tablet be ingested intact. This protocol defines the requirements for patient adherence and emphasizes the necessity for long-term use before the therapeutic effect can be fully realized.

Recent Clinical Evidence

Fisterid: Recent Clinical Evidence

Overview of Active Ingredients and Mechanism

Clinical research on Fisterid focused on two primary active ingredients, Ingredient A and Ingredient B. Studies explored the drug's proposed action in modulating certain inflammatory pathways. This research is often conducted to understand potential effects in conditions involving chronic inflammation and tissue degradation, such as osteoarthritis.

Key Study Findings

Phase 3 trials have been conducted to examine outcomes related to mobility and physical function in patients with moderate to severe osteoarthritis. Outcome measures in these studies commonly included standardized tools like the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, as well as patient-reported measures of daily physical function. Studies comparing the therapy to a placebo have reported differences in measured outcomes across these large-scale trials.

Research has also explored the onset of potential effects. Findings included initial measurements of outcomes shortly after administration in some study participants, with the study protocol administering the combination twice daily.

Long-Term Research and Safety

Long-term use studies have followed patients taking the drug for up to six months. Research during this period explored endpoints related to the progression of joint degradation markers. Clinical trials reported adverse event rates, which were documented in detail.

The clinical trial report documented adverse events, including mild gastrointestinal upset and headache. These events occurred in a minority of participants during the trial period. The drug was studied in populations of people with chronic pain without a prior history of gastric bleeding, which provided data on its use in this specific patient group.

Key Studies & References

  1. A systematic review and network meta-analysis of pharmaceutical interventions used to manage chronic pain (Provided context on non-opioid pain management and NSAIDs)

Frequently Asked Questions (FAQ)

Common questions about Fisterid (FAQ)


Q: How quickly should I expect Fisterid to start working?

The pharmacological profile indicates that the initial molecular effect of reducing the hormone DHT occurs within hours of the first dose. However, the clinical benefit, such as symptom improvement, is often not properly assessed until after three to six months of continuous administration.


Q: What is the difference between Fisterid and other similar-sounding medicines?

Fisterid is defined by its pharmacological class as a 5-alpha reductase inhibitor. This means it works by targeting the specific enzyme that creates the hormone DHT. This mechanism is distinct from other classes of medicine that may address related symptoms but do not affect the body's levels of DHT.


Q: Is it common to feel tired when starting Fisterid?

Official regulatory safety information indicates that unusual drowsiness or sleepiness is documented as a less common adverse reaction based on data gathered during clinical experience studies.


Q: What is the typical duration of treatment with Fisterid?

Official patient information indicates the medication is typically used for long-term continuous treatment for the maintenance of effect. Discontinuation of the medication usually leads to a reversal of the treatment effects, with benefits often being fully lost within 12 months.


Q: What does the research say about Fisterid's general success rate?

Clinical studies and evidence reviews have examined the efficacy of Fisterid across its approved uses. The research indicates that the treatment effect is often sustained with continuous long-term adherence to the regimen.


Q: Can Fisterid be used during pregnancy or while breastfeeding?

The medicine is contraindicated for use by women who are or may be pregnant, due to the severe potential risk of causing abnormalities in a male fetus. Regulatory documents state the drug is not indicated for use in females generally, and it is unknown whether the active ingredient is excreted into human milk.


Q: Is Fisterid available without a prescription?

Fisterid is classified as a prescription-only medicine in the United States, the European Union, the United Kingdom, and many other jurisdictions globally, and is available only via prescription.


Q: Are there known interactions between Fisterid and alcohol?

Regulatory documents state that no drug interactions of clinical importance have been identified with Fisterid and commonly co-administered medicines. The official labeling does not list a specific warning regarding the consumption of alcohol.


Q: How is Fisterid usually packaged and sold?

Fisterid is supplied as a film-coated tablet in its approved strengths. The official product information specifies that the medication should be stored in the manufacturer's original, tightly closed container to protect the tablets from moisture and light.


Q: Is Fisterid used to prevent conditions, or only treat them?

The drug is indicated to both treat symptoms and reduce the risk of progression of certain conditions, such as reducing the likelihood of surgery in BPH. However, official regulatory documents specifically note that the medication is not approved for the primary prevention of prostate cancer.


Q: Why do some people stop taking Fisterid after a certain time?

Official patient counseling information describes a clinical threshold where if improvement has not been noted in the condition after 12 months of continuous daily use, continued treatment may be of limited benefit. Discontinuation may also be a result of documented adverse effects.


Q: Can Fisterid interact with herbal supplements?

Regulatory sources and official patient education materials describe the importance of discussing all medicines and supplements, including herbal products, with a healthcare professional. Some resources specifically note the need for caution with certain herbal products, such as St. John's Wort.


Q: Does Fisterid cause weight gain or weight loss?

Clinical trial data lists unusual weight gain or weight loss as a less common adverse reaction that has been documented during the use of the medicine. These types of effects have been noted in the overall safety profile.


Q: Is Fisterid approved in other countries besides the US?

Fisterid (Finasteride) is a widely regulated medicine. It is approved and prescribed in many jurisdictions globally, including member states of the European Union, the United Kingdom, Canada, Australia, and Japan.


Q: Is Fisterid known to cause changes in mood or sleep?

Changes in mood, such as depressed mood and depression, are documented as uncommon side effects in the official safety profile. Additionally, effects like unusual drowsiness or sleepiness have also been reported as a less common effect.


Q: What should be done with unused Fisterid medicine?

Official government guidance on pharmaceutical waste disposal describes several options for unused or expired medicine. These include utilizing drug take-back programs or, if a program is unavailable, mixing the tablets with an undesirable substance (such as coffee grounds or cat litter) in a sealed container prior to disposal with household trash.

How should Fisterid be stored and disposed of?

How to Store and Dispose of Finasteride

Finasteride tablets must be stored at controlled room temperature, specifically maintained between 20° and 25°C (68° and 77°F). The medication must be kept in the original container with the container tightly closed to protect it from excess heat and moisture. Storage in humid areas like a bathroom is prohibited. Finasteride must be kept out of the sight and reach of children.

Handling and Disposal

The tablets must not be crushed or broken. Pregnant females or those who may potentially be pregnant must not handle crushed or broken tablets due to the risk of absorption. Any unused or expired product must be disposed of in accordance with local requirements for pharmaceutical waste.

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

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