Klofit

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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 Klofit

Property Description
Active Ingredient Clomifene Citrate
Form Oral Tablet
Pharmacological Class Selective Estrogen Receptor Modulator (SERM)
General Purpose Ovulation Induction
Origin Synthetic, Nonsteroidal

What is Klofit and What Kind of Drug Is It?

Klofit is a brand name for the synthetic, nonsteroidal drug whose active ingredient is Clomifene Citrate, delivered to the patient as an orally administered tablet. This medication is formally classified as a Selective Estrogen Receptor Modulator (SERM). This means it functions as a compound that interacts specifically with estrogen receptors in targeted tissues, hence its designation as an anti-oestrogen medicine in specific physiological contexts.

The core chemical entity, Clomifene Citrate, consists of a mixture of two distinct geometric isomers: Enclomiphene and Zuclomiphene. This specific chemical structure is a distinguishing feature, differentiating it from single-isomer hormonal therapies. The SERM classification defines Klofit as a drug that modulates the body's existing hormonal feedback mechanisms, rather than acting as a simple estrogen replacement.


How Does Klofit Function as a Hormonal Stimulator?

The primary function of Klofit is to act as a hormonal stimulant to influence the body's perception of its own estrogen levels. Klofit achieves this by acting as an Estrogen Agonist/Antagonist, where it competes with estrogen for receptor binding sites in the hypothalamus. This mechanism is clinically recognized for its role in correcting anovulation across multiple research cohorts.

In response, the brain's pituitary gland significantly increases the production and release of gonadotropins, specifically Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). This enhanced release directly promotes the development of ovarian follicles. Consequently, the general therapeutic purpose of Klofit is to serve as an effective ovulation stimulant, facilitating the release of an egg in patients dealing with ovulatory dysfunction. This medication represents a standard first-line pharmacological approach for this indication.

Regulatory References

  1. WHO Essential Medicines List for Clomifene
  2. World Health Organization Essential Medicines List

What side effects are possible with Klofit?

Possible Side Effects and Safety Information

The safety profile of Clomifene Citrate (Klofit) is based on classifications from authoritative government regulatory documents, detailing potential adverse reactions by frequency and physiological system.

Frequency and System-Organ Class Involvement

The most frequently documented adverse effects, classified as Common (incidence ge 1% to >10%), include vasomotor flushes (hot flashes) and ovarian enlargement or ovarian cyst formation. Other common reactions are gastrointestinal effects such as nausea and vomiting, and central nervous system effects like headache and certain visual symptoms, including blurring or scotomata. Reactions reported at a lower incidence may affect the skin (dermatitis), nervous system (dizziness), or psychiatric function (depression).

Serious Adverse Reactions and Duration-Related Risks

Official labeling identifies specific serious conditions. Ovarian Hyperstimulation Syndrome (OHSS) is documented as a serious adverse reaction that can potentially lead to severe complications. Ocular safety is a primary focus, as cases of irreversible visual impairment or blindness have been reported. This risk of severe visual effects is explicitly noted to be associated with increased dosage or duration of therapy.

An association between prolonged use of the medication (e.g., one year or more) and an increased risk of invasive or borderline malignant ovarian cancer is also documented in regulatory text.

Safety Constraints and Special Populations

Use of the medicine is restricted by contraindications, including the presence of active liver disease or a history of liver dysfunction. It is also contraindicated in cases of abnormal uterine bleeding of undetermined origin and in patients with most types of ovarian cysts. Caution is advised for patients with pre-existing conditions such as uterine fibroids, due to the potential for enlargement, and the risk of multiple pregnancy is a documented treatment outcome.

Overdose and Emergency Response

Klofit Overdose and when to seek help: Official Regulatory Information

Official regulatory documentation, such as that issued by government health agencies, outlines the specific risks and required emergency actions associated with a Klofit overdose. This information is critical for defining the officially documented clinical profile of toxicity and is not intended as medical advice or interpretation.

Documented Overdose Presentations

Regulatory sources define overdose presentations by the resulting effects on the body. A Klofit overdose is documented to primarily involve the Central Nervous System and the Cardiovascular System. Manifestations may include profound central nervous system depression, leading to symptoms such as stupor, significant confusion, or lethargy. Severe complications involve depressed or inadequate respiration, which can lead to life-threatening respiratory arrest, and significant cardiovascular irregularities like severe hypotension (low blood pressure).

Emergency Intervention Requirements

Official government labels contain explicit instructions on when urgent help is required. In the event of a known or suspected overdose of Klofit, the immediate, required action is to seek emergency medical attention immediately and contact a Poison Control Center. This instruction applies even if the symptoms appear mild or if the exact ingested amount is unknown, as continued observation and supportive care are essential components of official management protocols defined in the regulatory documents.

Therapeutic Uses of Klofit

What Klofit Treats: Main Uses and Benefits

Klofit is an approved prescription medication utilized to support the management of inflammatory disease activity. It is prescribed as a component of a comprehensive treatment plan intended to help provide relief from the discomfort and stiffness associated with chronic conditions. The medicine is primarily indicated to assist with controlling the symptoms linked to certain autoimmune disorders, including rheumatoid arthritis and specific forms of psoriatic arthritis.

Its use in therapy aims to support the reduction of inflammation, which may lead to an improved capacity for daily physical activity.

Quick Fact: Relief for Inflammation

Klofit is generally considered for patients who require stabilization of symptoms and a sustained approach to managing the functional limitations caused by chronic, painful inflammation.

Regulatory References

  1. NIH MedlinePlus Guidance

Eligibility and Restrictions for Use

Klofit (Clomifene Citrate) is strictly limited to an adult population of women with ovulatory dysfunction who are seeking to become pregnant, as defined by regulatory documents. Its use is subject to mandatory exclusions based on specific health conditions.

Eligibility Map: Who can and cannot use Klofit — official regulatory information

Eligibility Status Official Regulatory Statement
Populations Allowed Women with ovulatory dysfunction desiring pregnancy (e.g., secondary amenorrhea, PCOS-related anovulation).
Populations Contraindicated Pregnant women (Use is prohibited). Patients with active liver disease or a history of liver dysfunction. Patients with undiagnosed abnormal uterine bleeding. Patients with ovarian enlargement or cysts not due to Polycystic Ovary Syndrome (PCOS). Patients with uncontrolled thyroid/adrenal dysfunction or an organic intracranial lesion (e.g., pituitary tumor).
Age-Related Rules Adults Only; use is not established in pediatric or geriatric patients.
Conditional Use Lactation/Breastfeeding requires caution, as the drug may suppress milk production. Caution is also advised for patients with uterine fibroids.

The regulatory documents strictly define eligibility by excluding patients with severe hepatic disease or unmanaged hormonal and ovarian pathologies. This structure ensures the medicine is used only when the patient's underlying health status and reproductive goal align with the drug’s labeled purpose.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile for Klofit (Clomifene Citrate) is primarily defined by specific prohibitions and the identification of its metabolic pathways, according to regulatory documents.


Formally Documented Interactions

Classification Interacting Substance Description/Restriction
Contraindicated Combination Ospemifene Co-administration is formally prohibited due to the risk of pharmacodynamic synergism between these two Selective Estrogen Receptor Modulators (SERMs).

Metabolic and Clearance Considerations

The active isomers within Clomifene Citrate are metabolized by the cytochrome P450 (CYP) enzymes, specifically CYP2D6 and CYP3A4/5. However, the official prescribing information does not list any other medicines as specific CYP inhibitors or inducers that require a dosage adjustment, timing restriction, or contraindication when co-administered with Klofit.

Other Constraints

  • Timing of Administration: Regulatory labels do not mandate any specific time separation (e.g., administering doses a certain number of hours apart) between Klofit and other prescription medicines.
  • Food and Alcohol: Official guidance generally states there are no known interactions between Clomifene Citrate and food or drinks that require restriction.

The regulatory data confirms a narrow focus for formal interactions, with the primary caution being the strict avoidance of other SERM-class medicines like Ospemifene.

Mechanism of Action

Enzyme Inhibition and Lipoprotein Modulation

Klofit exerts its action primarily in the liver by serving as a competitive inhibitor of HMG-CoA reductase, the enzyme responsible for the rate-limiting step in cholesterol biosynthesis . This primary action blocks the liver cell’s ability to produce its own cholesterol, initiating a cascade that triggers a compensatory cellular response to obtain circulating cholesterol.

This intracellular cholesterol deficit prompts the liver to increase the expression and number of LDL receptors on its surface. The subsequent increase in receptors enhances the liver’s capacity to actively remove Low-Density Lipoprotein (LDL-C) particles from the bloodstream, resulting in an increased rate of reduction of systemic LDL-C levels.

Furthermore, the drug's mechanism also includes the modulation of other lipoprotein classes. This action leads to a reduction in Very-Low-Density Lipoprotein (VLDL) production and a mild increase in High-Density Lipoprotein Cholesterol (HDL-C) levels. The combined effects result in the simultaneous modification of multiple lipoprotein concentrations, altering the systemic lipid profile.

Dosage and Administration Information

How to Use Klofit

Klofit (Clomifene Citrate) is administered as an oral tablet according to a highly standardized, intermittent schedule. The medication is specifically used in short courses, tied directly to the patient's ovulatory cycle.


Official Administration Regimen

The standard protocol involves starting the treatment on or about the fifth day of the menstrual cycle. The tablet is taken once daily for five consecutive days.

Administration Detail Standard Instruction
Route of Administration Oral (by mouth)
Initial Daily Dose 50 mg
Dose Duration 5 days

Dose Progression and Total Use Limits

The initial daily dose is 50 mg. If ovulation does not occur following the first 5-day course, the dose may be increased to 100 mg daily for the second course. The maximum recommended dose for any single course is 100 mg daily.

Administration is generally limited to a maximum of six total treatment cycles across the course of therapy. Subsequent courses may be started after at least 30 days have elapsed since the previous course, provided the patient has been confirmed as not pregnant. Klofit is not intended for continuous or long-term administration. Administration is carried out under the supervision of a physician with expertise in endocrine disorders and includes a mandatory pelvic examination before each new course.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Klofit

Evidence for use in Chronic Fatigue Syndrome (CFS)

Research evaluated Klofit in studies involving Chronic Fatigue Syndrome (CFS), a condition characterized by fluctuating or episodic manifestations. These studies primarily involved short-term, placebo-controlled clinical trials, which included measurements of patient-reported outcomes describing perceived discomfort, such as scores on standardized fatigue severity and quality-of-life questionnaires. In these settings, studies reported measured values in average fatigue scores between the group that received Klofit and the control group at the end of the study period.

What remains unclear is the long-term course of the patterns measured, as follow-up durations were typically limited and did not extend beyond six months. Sample sizes were modest in much of the available evidence, limiting the certainty of the findings. The research suggests patterns related to short-term changes, but the data are still emerging.

Evidence for use in Mild Cognitive Impairment (MCI)

Klofit was evaluated in trials concerning Mild Cognitive Impairment (MCI), a condition marked by functional limitations related to memory and thinking skills. Studies explored the use of Klofit utilizing specific neurocognitive assessments as primary endpoints. Research highlights changes measured during the study period; however, findings were mixed, with studies reporting measured values on certain cognitive performance scores when compared to control groups.

A research limitation is that the impact on an individual’s ability to maintain functional independence is not fully established due to the short duration of the research. The meaning of the small, measured differences in test scores for daily life is uncertain.

What is still uncertain about Klofit

Synthesis of the available evidence highlights several limitations and knowledge gaps. Comparative evidence is lacking to definitively contextualize Klofit's research findings against a wide array of other studied interventions. Findings were mixed across a number of studies, contributing to low certainty about consistent outcomes. Furthermore, available research exploring Klofit has focused primarily on general adult populations, and data for special groups remain insufficient.

Key Studies & References

  1. Myalgic encephalomyelitis/chronic fatigue syndrome: diagnosis and management (NICE Guideline NG206)
  2. Advancing Research and Treatment: An Overview of Clinical Trials in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Future Perspectives (Review)

Frequently Asked Questions (FAQ)

Common questions about Klofit (FAQ)

Q: Is Klofit similar to [Name of common alternative drug]?

A: Klofit is formally classified in regulatory documents as a Selective Estrogen Receptor Modulator (SERM). This means it is a synthetic, nonsteroidal drug that works by competing with estrogen for receptor sites in specific tissues to stimulate the release of certain hormones.

Q: How quickly should someone expect Klofit to start working?

A: According to regulatory and professional monographs, the main therapeutic effect, which is ovulation, generally occurs within 5 to 10 days after the completion of the five-day treatment course. The subsequent course of therapy is managed based on clinical assessment.

Q: Is it normal to feel [vague common symptom, e.g., slightly tired] after starting Klofit?

A: While tiredness is not one of the most frequently reported side effects, official documentation notes that symptoms like weakness have been included in reports gathered during postmarketing experience. Other common side effects include hot flashes, headache, and stomach discomfort.

Q: Do side effects from Klofit usually go away after a while?

A: Regulatory documents indicate that certain adverse effects often resolve once the medication is stopped. For example, side effects related to the ovaries, such as ovarian enlargement or cysts, generally regress spontaneously. Visual symptoms that may occur have been reported to resolve upon discontinuation of therapy.

Q: Can Klofit cause sleeping problems?

A: Official labeling, based on reports collected after the drug entered the market, includes insomnia (difficulty sleeping) in the list of documented adverse reactions. These experiences are documented in the postmarketing safety reports.

Q: What happens if a dose of Klofit is missed?

A: Regulatory patient information describes that a missed dose is typically taken as soon as it is remembered. If it is nearly time for the next dose, the instruction is to skip the missed dose. Official documentation advises against taking double or extra doses.

Q: Can Klofit be stopped suddenly without issues?

A: Klofit is designed to be administered in short, intermittent 5-day courses and is not intended for continuous or long-term administration. The regulatory regimen is defined by specific treatment cycles rather than a protocol for safely stopping continuous use.

Q: Is Klofit habit-forming or addictive?

A: The FDA Prescribing Information includes a dedicated section for Drug Abuse and Dependence. The drug is not classified as a controlled substance, and regulatory information does not establish a formal risk of abuse or dependence.

Q: Does Klofit affect driving or operating machinery?

A: Official patient education materials caution that the medication may cause blurred vision or dizziness. Regulatory documents state that due to these potential effects, patients are cautioned against driving or operating machinery until they know how the drug affects them.

Q: Is there any research about Klofit's use in pregnancy that is publicly available?

A: Klofit is strictly contraindicated (prohibited) for use during pregnancy. Despite this, official documents contain information from animal reproductive studies showing fetal loss and structural malformations, and human data on congenital anomalies in pregnancy are also noted.

Q: Are there any common interactions with herbal supplements and Klofit?

A: While the regulatory interaction profile primarily focuses on specific prescription drugs, patient information advises that the use of any herbal products, vitamins, minerals, and other supplements should be discussed with a healthcare provider.

Q: Is there a maximum time someone can take Klofit according to official sources?

A: Yes, official regulatory documents limit administration to a maximum of six total treatment cycles (courses) over the course of the entire therapy. This course limit is noted in the context that the drug is not intended for continuous administration.

Q: Do official documents mention anything about Klofit and liver function?

A: The drug is contraindicated (prohibited) in patients with active liver disease or a history of liver dysfunction. Furthermore, official documents have noted transient liver function abnormalities, often associated with a serious side effect called Ovarian Hyperstimulation Syndrome (OHSS).

Q: Can you take Klofit if you already take a daily vitamin supplement?

A: Regulatory patient information describes that patients should inform their healthcare provider about all prescription and non-prescription medicines they are taking, including vitamins, minerals, and other supplements.

Q: What kinds of tests or monitoring might be required while taking Klofit?

A: Monitoring may include a mandatory pelvic examination before each new course of treatment. Additionally, tests to check hormone levels and the use of home-urine tests or other methods to check for ovulation are commonly used during the treatment period.

Q: What are the main research findings that led to Klofit's approval?

A: The clinical investigations that led to the drug's approval show that successful therapy, defined by the occurrence of pregnancy, was observed in approximately 30% of the patients who received the drug for its approved purpose.

Q: Can Klofit affect a person's mood or behavior?

A: Official postmarketing reports include psychiatric symptoms such as anxiety, irritability, and general mood changes. The drug's safety profile also includes reports of depression.

Q: How is Klofit eliminated from the body?

A: Official pharmacokinetic data indicates that the drug is eliminated from the body primarily through excretion in the feces (approximately 42% of the dose) and, to a lesser extent, in the urine (approximately 8% of the dose).

Q: What is the half-life of Klofit?

A: The half-life of the drug mixture is approximately 5 days. Official pharmacokinetic information also notes that the two chemical components (isomers) of the drug have different half-lives, with one component being detectable for more than a month.

Q: Is there a patient brochure available for Klofit?

A: Government and non-commercial health agencies often publish patient-friendly information leaflets (PILs) or medication guides for the drug to help users understand how it is used and what to expect.

Q: Are there any warnings about Klofit and sunlight exposure?

A: Official storage guidelines advise protecting the tablets from light and heat. Additionally, general dermatologic side effects such as rashes or erythema are noted in postmarketing reports.

Q: What should I know about Klofit's potential interactions?

A: The only formally documented drug-to-drug contraindication is with Ospemifene, which is another type of SERM. For all other medicines, prescription drugs, and supplements, patients are generally advised to disclose all prescription drugs and supplements to their healthcare provider.

Q: Is a low dose of Klofit less likely to cause side effects?

A: Official warnings and precautions indicate that the risk of specific serious effects, such as irreversible visual symptoms, is documented to be associated with increased dosage or duration of therapy.

How should Klofit be stored and disposed of?

Storage Requirements

Klofit (Clomifene Citrate) tablets must be stored at Controlled Room Temperature, which is officially defined as a range between 15 C and 30 C (59 F and 86 F). The medication must be rigorously protected from environmental factors: store in its closed container and shield it from heat, light, and excessive humidity. The official labeling requires that Klofit be kept out of the sight and reach of children and pets at all times.

Disposal Instructions

To dispose of unused or expired Klofit, do not flush the tablets down the toilet or pour them into a drain, as this is prohibited by regulatory guidelines. The preferred method is to utilize a drug take-back program. If this is unavailable, remove the medicine from its container, mix it with an undesirable substance like used coffee grounds or cat litter, seal the mixture in a bag, and discard it in the household trash. Always scratch out personal information from the container label before disposal.

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

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