Fefol

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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 Fefol

Quick Facts about Fefol

Property Description
Active Ingredients Ferrous Sulfate and Folic Acid
Dosage Form Oral Capsule (Sustained-release)
Pharmacological Class Haematinic Agents
Common Purpose Supports Red Blood Cell Production
Origin Synthetic

The Composition and Classification of Fefol

Fefol is defined as a combination drug that functions as a Haematinic Agent, a pharmacological class of medicines specifically used to support the formation of healthy blood by supplying key precursors. The preparation contains two distinct active, synthetically derived ingredients: Ferrous Sulfate (a source of elemental iron) and Folic Acid (the synthetic form of Vitamin B9). This combination is clinically recognized for its efficacy in supplementing both iron and folate, particularly in demographics with high nutritional needs. Preparations combining iron and folic acid are recognized for their role in public health.

Form and Sustained-Release Delivery

The preparation is formulated as an Oral Capsule, intended for administration via the oral route. Fefol is often associated with its specialized sustained-release mechanism, which is a differentiating factor from basic, immediate-release tablets. This modified-release characteristic means the Ferrous Sulfate and Folic Acid are released slowly and consistently over an extended period after ingestion. This system is intended to provide a steady supply of elemental iron for systemic absorption, which may influence gastrointestinal tolerability compared to immediate-release iron supplements.

General Therapeutic Purpose

The primary therapeutic purpose of Fefol is to serve as a targeted therapeutic supplement to restore and maintain adequate body stores of both iron and folate. A typical use scenario involves providing necessary nutritional support during periods of increased biological demand, such as pregnancy, where requirements for both nutrients are significantly elevated. Iron is necessary for the transport of oxygen via hemoglobin throughout the body. By supplying these two essential factors, the medicine supports the process of erythropoiesis, which is the body's mechanism for generating functional Red Blood Cells (RBCs).

Regulatory References

  1. NIH Office of Dietary Supplements

What side effects are possible with Fefol?

Possible side effects and safety information

The official safety profile for the combined preparation of Ferrous Sulfate and Folic Acid (Fefol) is defined primarily by its gastrointestinal effects and specific constraints related to iron and folate supplementation.


Adverse Reaction Scope

The regulatory labeling groups possible effects predominantly within Gastrointestinal Disorders and Immune System Disorders. Expected and frequently documented adverse reactions, classified as Common, include nausea, vomiting, abdominal discomfort, constipation, and diarrhea. The darkening of the stools is a frequent and expected consequence of the iron component that persists for the duration of treatment.

Classification Aspect Documented Characteristics
Frequency-classified reactions Common (GI effects); Rare (Hypersensitivity)
System-organ classes involved Gastrointestinal, Immune System, Skin and Subcutaneous Tissue
Serious adverse reactions Anaphylaxis, Accidental fatal iron poisoning in children

Safety Constraints and Considerations

Specific regulatory constraints limit the use of this medicine. The preparation is contraindicated in individuals with conditions associated with iron overload, such as haemochromatosis and haemosiderosis. Furthermore, due to the folic acid component, the medicine is contraindicated in any patient with untreated Vitamin B12 deficiency (Pernicious Anemia), as folate may mask the hematological signs of the deficiency while severe neurological damage progresses. Safety notes specifically warn that accidental iron overdose is a leading cause of fatal poisoning in the pediatric population and that the gastrointestinal side effects may be more pronounced at the initiation of therapy.

Overdose and Emergency Response

The overdose profile for Fefol is primarily defined by the severe systemic toxicity potential of the Ferrous Sulfate component. Regulatory labeling includes the warning that accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6, necessitating that the medicine be strictly kept out of their reach.

Initial overdose manifestations typically involve severe corrosive injury to the gastrointestinal tract, presenting as severe abdominal pain, vomiting (which may include blood or coffee ground material), and bloody diarrhea. These initial symptoms may be followed by a latent phase of apparent improvement before a rapid decline.

Severe, life-threatening outcomes include systemic effects such as shock, cardiovascular collapse, seizures, coma, and progressive multi-organ damage, particularly liver failure and metabolic acidosis. Doses of elemental iron 40 mg/kg are associated with a risk of systemic toxicity.

Due to the severity of these documented manifestations, immediate medical attention or contact with a poison control center is required for any suspected overdose. The official management of systemic toxicity involves specialized procedural interventions, including gastric lavage, whole-bowel irrigation, and the use of the specific antidote, Desferrioxamine (Deferoxamine). Additionally, high doses of the Folic Acid component may mask the progression of pernicious anemia.

Therapeutic Uses of Fefol

What Fefol Treats: Main Uses and Benefits

Fefol is commonly used to help with conditions presenting with systemic or localized discomfort, such as Iron Deficiency Anemia (IDA) and Folate Deficiency. This dual supplement is relevant in contexts involving heightened systemic burden and symptoms that interfere with daily functioning. This combined therapy serves as an intervention for these conditions.

The medication supports the management of symptom clusters that may become intense or disruptive, including persistent chronic fatigue, systemic weakness, and related signs like dizziness. Fefol is applied in contexts where these symptoms create noticeable physiological strain and interfere with daily comfort. The key benefit here supports the patient during difficult episodes by easing distress and is relevant in contexts marked by increased discomfort or tension, especially during phases like the preconception period and pregnancy.

“Fefol is commonly used during phases of significantly increased physiological stress, ensuring essential reserves are in place.”

Quick Fact: Relief for Fatigue
The supplement helps address the symptom burden of weakness and lethargy, providing supportive relief when symptoms interfere with routine activities.

Eligibility and Restrictions for Use

The official regulatory documentation for Fefol establishes strict criteria for its population eligibility and absolute contraindications.

Populations for Whom Use is Established

Fefol is established for use in adults and adolescents with confirmed iron and/or folate deficiency. Its use is also recommended for pregnant and lactating women for deficiency prophylaxis and treatment. Official labels generally deem it suitable for use during the remainder of pregnancy, though some guidance advises against prophylactic use during the first trimester.

Populations with Absolute Contraindications

The medicine must not be used in patients with conditions of Iron Overload, such as haemochromatosis or haemosiderosis. It is also prohibited for individuals with a known hypersensitivity to any component or those receiving repeated blood transfusions.

Fefol is strictly contraindicated in cases of Megaloblastic Anaemia due to untreated Vitamin B12 deficiency, as the folic acid can mask this serious underlying condition.

Age and Condition Restrictions

The sustained-release capsule formulation is generally not recommended for children under 12 years of age. Furthermore, use is contraindicated in patients with severe active peptic ulceration, ulcerative colitis, regional enteritis, or severe hepatic and renal dysfunction.

What should I know about interactions with other medicines?

Interactions with other Medicines and Products

The official interaction profile for Fefol (Ferrous Sulfate and Folic Acid) is defined by pharmacokinetic absorption interference and pharmacodynamic effects, establishing required conditions for concurrent use. The majority of clinically significant interactions involve the Ferrous Sulfate component.


Official Interaction Statements

Interaction Type Interacting Substances/Conditions
Absorption Interference Oral iron reduces the absorption of medicines including Tetracycline and Quinolone antibiotics, Levothyroxine (L-thyroxine), and Bisphosphonates (e.g., Ibandronate), leading to decreased plasma levels of the co-administered drug.
Pharmacodynamic Antagonism Folic Acid may antagonize the anticonvulsant action of antiepileptic drugs such as Phenytoin, potentially reducing seizure control. Ferrous sulfate also decreases the hypotensive effect of Methyldopa.
Timing Separation Rules Doses of oral iron and medications such as Levothyroxine or Quinolone antibiotics must be separated by at least two to six hours to mitigate absorption interference.
Contraindicated Use The use of Folic Acid is formally contraindicated in patients with undiagnosed anemia or untreated Cobalamin (Vitamin B12) deficiency. Oral iron is contraindicated with Parenteral Iron Therapy.

Food and Substance Impact

Food products containing milk, calcium, high-fiber content, coffee, and tea may impair the systemic absorption of oral iron. Conversely, Vitamin C (Ascorbic Acid) is officially documented to increase iron absorption. Chronic intake of alcohol may increase the elimination and decrease the absorption of Folic Acid.

Mechanism of Action

Mechanism of Action: Red Blood Cell Production

This section outlines the biological process of how the drug's active components, iron and folic acid, act together at a cellular and systemic level to influence the formation and maturation of red blood cells, resulting in an increase in the body's overall oxygen-carrying capacity.


Heme and Hemoglobin Synthesis

The iron component, supplied as ferrous iron ( Fe^2+), is absorbed and acts as a direct substrate for the heme synthesis pathway. This mechanistic domain involves the incorporation of the iron into the structure of hemoglobin, the protein responsible for binding and carrying oxygen. The resulting physiological effect is the formation of hemoglobin molecules within red blood cells.


DNA Synthesis and Cell Proliferation

The folic acid component is converted to its active form, which is a critical co-factor in the synthesis of DNA and RNA within the bone marrow cells. This process is required for the proliferation and maturation of erythroblasts (red blood cell precursors). This mechanistic domain contributes to the formation of red blood cells by facilitating their division and maturation.


Coordinated Hemopoietic Influence

The mechanism operates through a coordinated action: the iron component addresses the functional structure (hemoglobin), and the folic acid component addresses the cell's production and maturation (DNA synthesis). This combined mechanism influences the entire hemopoiesis system, resulting in increased circulating red blood cell mass and systemic oxygen delivery capacity.

Dosage and Administration Information

How to Use Fefol: Administration Guidelines

This section outlines the usage instructions for Fefol (ferrous sulfate and folic acid modified-release capsules).

Administration Scope

Field Instruction
Route of Administration Oral (Swallowed)
Dosing Schedule Adult Prophylaxis: One capsule daily. Adult Treatment: Two capsules daily. Dose adjustments for severe anemia must be determined by a healthcare provider.
Timing in Relation to Meals Best absorbed on an empty stomach. May be taken after food to minimize gastrointestinal discomfort. Avoid taking within one hour before or two hours after consuming milk, coffee, tea, or whole grains.
Age-Group Rules Recommended for use during pregnancy. Use in children is generally not recommended or contraindicated, depending on the specific product label.
Missed-Dose Rules Take the missed dose immediately unless the next dose is due within two hours, in which case the missed dose should be skipped. Do not take a double dose.

Procedural Conditions and Handling

Fefol modified-release capsules must be swallowed whole with water. The capsules must not be sucked, chewed, or kept in the mouth before swallowing due to the risk of mouth ulceration and tooth discoloration. If swallowing the capsule is difficult, the capsule may be opened and the contents mixed with soft, cool food, but the pellets themselves must not be chewed. The duration of therapy is determined by laboratory follow-up to ensure iron stores are replenished.

Recent Clinical Evidence

Research Evidence: Overview of Studies for Fefol (Ferrous Sulfate and Folic Acid)


Evidence for Use in Iron Deficiency Anemia (IDA) and Folate Deficiency

The combination of iron and folic acid was studied in research exploring conditions that involve systemic or functional imbalance, such as Iron Deficiency Anemia (IDA) and Folate Deficiency. The research base includes Randomized Controlled Trials (RCTs) and larger Meta-analyses conducted in adult populations diagnosed with these specific deficiencies. These studies examined key nutritional markers, including changes in Hemoglobin ( Hb) concentration, Serum Ferritin levels, and other Red Blood Cell indices.

Research also explored patient-reported outcomes describing perceived discomfort, used in studies examining patient-reported experiences related to physical discomfort. Specifically, researchers monitored outcomes related to chronic fatigue and systemic weakness. Findings describe patterns observed in the studies related to shifts in the measured blood parameters. Some trials reported how symptoms were measured in the observed populations, and data show patterns related to changes in patient self-reports of fatigue and weakness during the defined time intervals.


Evidence for Nutritional Support During Pregnancy and Preconception

The use of iron and folic acid was evaluated in women during the preconception period and throughout pregnancy. This area includes a wide range of studies, including numerous Randomized Controlled Trials and large-scale reviews that inform major global health guidelines. These studies were designed to monitor nutritional status outcomes, specifically the status of Hb and Folate, and to assess the rate of change in nutritional status when observed in trials.

Studies were also applied in research contexts involving physiological strain, and monitored patient-reported outcomes describing perceived discomfort, such as dizziness and systemic weakness. Research highlights changes measured during the study period, related to the status of key nutritional markers when the supplement was observed in these populations. The reported follow-up duration for this research scenario was often conducted across the entire nine-month gestation period.


What Remains Uncertain and Areas for Future Study

It is important to understand that the research structure has limitations. For instance, comparative evidence is lacking between the specific sustained-release formulation of Fefol and standard immediate-release iron/folate preparations regarding nutritional status outcomes. The research provides limited insight into the long-term data related to the specialized release mechanism, relative to other formulations.

Data for certain groups remain insufficient. For example, there is limited information regarding the long-term use patterns in older adult populations, and research findings may be mixed or variable in some subgroups. Sample sizes were modest in some studies evaluating patient-reported outcomes, and evidence quality varies across studies, meaning certainty remains low for certain findings. These research limitations highlight what is still uncertain.

Frequently Asked Questions (FAQ)

Common questions about Fefol (FAQ)


Q: What is the difference between Fefol and generic ferrous sulfate?

A: Fefol is officially defined as a combination product because it contains two active ingredients: Ferrous Sulfate (iron) and Folic Acid (Vitamin B9). Generic ferrous sulfate typically contains only the iron component. Official product information also notes that Fefol is a modified-release capsule formulation, which is a key difference from standard, immediate-release iron tablets.

Q: What is the role of folic acid in the Fefol capsule?

A: The folic acid component is included because it is essential for the production and proper maturation of red blood cells. Fefol is used to prevent or treat deficiencies of both iron and folic acid, particularly in contexts where the body has a high demand for these nutrients, such as during pregnancy.

Q: Is it safe to take Fefol if I have acid reflux?

A: Regulatory documents indicate that common gastrointestinal effects like heartburn, nausea, and abdominal discomfort are possible side effects of the medicine. Official warnings also note that oral iron may be contraindicated in patients with severe active peptic ulceration or other inflammatory bowel conditions. A healthcare provider can assess use in the context of pre-existing conditions like acid reflux.

Q: Is there a risk of iron overload from taking Fefol long-term?

A: The medicine is contraindicated (should not be used) in patients already diagnosed with conditions of iron overload, such as haemochromatosis. Official guidance indicates that the duration of use is typically monitored and determined by laboratory follow-up. Using iron supplements for extended periods should be assessed by a healthcare provider.

Q: Does Fefol help with low energy or fatigue?

A: Fefol is used to treat iron deficiency anaemia, a condition where common symptoms can include systemic fatigue and weakness. The medicine is intended to address the underlying deficiency that may be associated with these symptoms by supporting red blood cell production and oxygen transport.

Q: Does Fefol interfere with blood tests?

A: Regulatory documents state that the duration of treatment is determined by subsequent laboratory follow-up to confirm that iron stores have been adequately restored. While the medicine is intended to directly influence blood parameters like hemoglobin and ferritin, official sources do not state that it interferes with the accuracy of routine blood tests.

Q: What should I do if I think I'm having an allergic reaction to Fefol?

A: Serious reactions like anaphylaxis (a severe allergic reaction) have been reported. Signs such as hives, difficulty breathing, or swelling of the face, lips, tongue, or throat are noted in safety warnings. These symptoms require immediate emergency medical attention as officially mandated.

Q: Is Fefol safe for teenagers?

A: Official product information confirms that the medicine is established for use in adolescents and adults with confirmed iron and/or folate deficiency. However, regulatory guidance generally states that the modified-release capsule formulation is not recommended for children under 12 years of age.

Q: Does Fefol have a special coating to help absorption?

A: The formulation is defined as a delayed-release or modified-release capsule. This specialized delivery system is designed to release the iron and folic acid slowly and consistently over an extended period. This mechanism is intended to influence systemic absorption and may improve gastrointestinal tolerability compared to standard forms.

Q: What if I vomit after taking Fefol?

A: Vomiting is listed as a common adverse reaction to the medicine. Official safety information notes that if vomiting is severe, or if the vomited material is dark or resembles coffee grounds, it may be a sign of a serious event, such as an iron overdose, and official guidance emphasizes the importance of seeking emergency medical attention immediately.

Q: Is Fefol used for things other than treating anemia?

A: Yes. While a primary use is treating iron deficiency anemia, the preparation is also used to prevent deficiencies of both iron and folic acid. A typical scenario involves providing necessary nutritional support during times of increased biological demand, such as throughout pregnancy.

Q: What is the maximum amount of time Fefol is prescribed for?

A: Regulatory guidance states that the duration of therapy is determined by laboratory follow-up, which involves monitoring by a healthcare professional. Some clinical guidance suggests caution regarding administration of iron for longer than six months, except in patients with continuous bleeding or other specific, documented medical needs.

Q: Are there different strengths of Fefol available?

A: Yes, regulatory public summaries indicate that different combinations and strengths of the product and its related versions are available internationally. Common formulations include specific amounts of Ferrous Sulfate and Folic Acid, and related versions may also contain added minerals, such as Zinc.

Q: Is it better to take Fefol in the morning or at night?

A: Official documentation indicates the medicine is best absorbed on an empty stomach, but there is no specific regulatory instruction stating a preference for morning or night time. Taking it after food is a commonly accepted measure used to minimize potential gastrointestinal discomfort.

How should Fefol be stored and disposed of?

Storage and Disposal: Official Regulatory Information

The storage and disposal of Fefol capsules are governed by specific regulatory requirements to maintain product stability and ensure public safety.

Entity Official Regulatory Requirement
Storage Temperature Store below 30°C or 25°C, depending on regional labeling.
Environmental Protection Must be protected from light and moisture.
Packaging Rules Store in the original package to maintain protection.
Child Safety Keep out of the reach and sight of children due to the risk of serious iron poisoning.
Disposal Instructions No special requirements are documented for disposal of the unused product; return unused medicine to a pharmacist.

These mandated conditions define how the product must be stored and secured from environmental factors and children. Regulatory sources classify disposal as non-hazardous, without special handling.

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

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