Regenon

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Regenon

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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 Regenon

Property Description
Active ingredient Amfepramone (Diethylpropion)
Form Hard capsule or film-coated tablet
Pharmacological class Anorectic Agent (CNS Stimulant)
Origin Synthetic compound

Regenon is a synthetic pharmacological preparation containing the active substance Amfepramone, which is also known as Diethylpropion. This compound is categorized primarily as an anorectic agent—meaning it functions as an appetite suppressant—and belongs to the broader pharmacological class of Sympathomimetic Amine Anorectics. Amfepramone is a substituted amphetamine derivative with action on the central nervous system.

Composition and Form: The Diethylpropion Component

The core of the product is its single active ingredient, Amfepramone, a chemical derivative classified as a cathinone analogue. Chemically, the substance is utilized within the oral pharmaceutical preparation, typically manufactured as a hard capsule or a film-coated tablet. Diethylpropion is a central stimulant with a defined effect on regulating food intake. Regenon is specifically known for its controlled-release capsule, a feature that distinguishes it from immediate-release tablet forms by providing a prolonged pharmacological effect.

General Purpose: Supporting Weight Management

The general purpose of Regenon is to provide support for individuals attempting to manage excess weight by facilitating adherence to a reduced-calorie dietary plan. It achieves this by acting in the brain as a CNS stimulant, thereby directly inducing a feeling of satiety and reducing the sensation of hunger. The intended general benefit is the pharmacological assistance provided to manage appetite control, helping patients establish a necessary and sustained caloric deficit essential for successful weight reduction.

Regulatory References

  1. WHO Expert Committee on Drug Dependence - Amfepramone
  2. EMA confirms recommendation to withdraw marketing authorisation for amfepramone medicines

What side effects are possible with Regenon?

Possible Side Effects and Safety Information for Regenon (Diethylpropion)

Regenon, which contains the active substance diethylpropion, is associated with a safety profile based on its classification as a sympathomimetic amine. The adverse reactions are formally documented according to System Organ Class (SOC) and frequency classification (e.g., Very Common, Common, Rare) in regulatory labels.

Key Adverse Reaction Categories

Adverse reactions commonly involve the Nervous system, the Psychiatric system, the Cardiovascular system, and the Gastrointestinal system. These may include, but are not limited to, dry mouth, dizziness, insomnia, nervousness, and cardiac effects.

Serious and Clinically Significant Adverse Reactions

Official regulatory documents emphasize the risk of Pulmonary Arterial Hypertension (PAH), an often fatal disorder, particularly when the medicine is used for longer than the recommended short-term duration (typically up to three months). Other serious documented risks include cardiovascular events (e.g., palpitations, increased blood pressure) and the potential for drug dependency or abuse.

Safety Restrictions and Monitoring

Contraindications specified in regulatory texts generally prohibit use in patients with a history of cardiovascular disease, severe hypertension, hyperthyroidism, glaucoma, or a history of drug abuse. Caution is required in patients with pre-existing mild cardiovascular disease or epilepsy, where close monitoring is necessary. Furthermore, the drug is not recommended for use during pregnancy due to potential risks, and its safety and efficacy in children under 16 years of age have not been established. Use must be strictly time-limited as defined by the prescribing information to minimize the risk of serious complications and dependence.

Overdose and Emergency Response

Overdose and When to Seek Help

Regenon (Amfepramone), a Central Nervous System (CNS) stimulant, has a documented overdose profile defined by severe signs of sympathomimetic toxicity in government regulatory labels.

Documented Clinical Manifestations

An overdose may present with signs of CNS overstimulation, including restlessness, tremor, hyperreflexia, panic states, and confusion. Cardiovascular effects documented in official labeling include tachycardia, arrhythmias, and fluctuations in blood pressure (hypertension or hypotension). Nausea, vomiting, and abdominal cramps may also occur.

Severe Outcomes and Emergency Action

Severe outcomes documented in official regulatory sources include convulsions, coma, and circulatory collapse. The development of toxic psychosis may follow chronic excessive use.

Immediate medical attention is required for any suspected overdose. Official guidance mandates that users contact emergency services immediately if the person has collapsed, experienced a seizure, has trouble breathing, or cannot be awakened. Guidance also includes contacting a poison control center for further instructions.

Overdose Management

The management of overdose is stated to be largely symptomatic and supportive, as no specific antidote is known. Official procedures for managing severe signs may include gastric lavage to reduce drug absorption and the use of a barbiturate for managing severe CNS excitation. An increased risk of toxic reactions is noted in regulatory documents for patients with impaired renal function.

Therapeutic Uses of Regenon

What Regenon Treats: Main Uses and Benefits

Regenon, which contains the active ingredient Amfepramone, is commonly used to provide symptomatic support in the management of Exogenous Obesity, a condition characterized by periods of heightened symptoms related to caloric intake and difficulty maintaining a functional weight. The active ingredient is considered relevant in the management of obesity as a short-term adjunct in a comprehensive regimen of weight reduction based on caloric restriction.

This medication is applied across therapeutic domains involving significant symptomatic burden, including conditions characterized by periods of heightened symptoms related to obesity and associated health risks. The primary therapeutic benefit is in addressing symptoms related to systemic imbalance concerning appetite. It is applied in contexts where patients experience excessive hunger (hyperphagia) and an impaired ability to feel satisfied.

By helping to ease the burden of these symptoms, the medication supports the patient in establishing the necessary lower caloric intake. This short-term symptomatic support may assist patients in coping more steadily with the initiation of the overall lifestyle regimen, and helps to improve day-to-day comfort during the difficult, early periods of a restricted diet.

“This short-term symptomatic support is intended to give patients an initial therapeutic boost to assist with adherence to the overall lifestyle regimen.”


Quick Fact: Relief for Excessive Hunger and Impaired Satiety

Regulatory References

  1. DailyMed official labeling overview

Eligibility and Restrictions for Use

Who Can and Cannot Use Regenon?

Regenon (Amfepramone) is strictly intended for adults who meet specific starting Body Mass Index (BMI) criteria as an adjunct to a short-term weight-reduction regimen based on caloric restriction. Use is not recommended or contraindicated in children and adolescents due to unestablished safety and efficacy. Use in older adults (65 and over) requires special caution.

Regulators have defined numerous absolute contraindications for use. The medicine is strictly prohibited for patients with pre-existing, unstable, or severe cardiovascular diseases, including pulmonary hypertension, severe hypertension, and cerebrovascular disease. It is also contraindicated in patients with hyperthyroidism, glaucoma, or a history of drug abuse or agitated states.

Eligibility is further restricted by physiological state. The medicine is contraindicated in women who are pregnant or breastfeeding. Patients with severe hepatic or severe renal impairment must not use this medicine. Additionally, use is contraindicated within 14 days of taking Monoamine Oxidase Inhibitors (MAOIs), and continuous use is strictly limited to a short-term maximum duration (e.g., 12 weeks).

What should I know about interactions with other medicines?

The official regulatory profile for Regenon (Amfepramone/Diethylpropion) details significant interaction risks, primarily related to its sympathomimetic amine classification. The information provided reflects only the constraints and outcomes documented by government health authorities.

Contraindicated Combinations and Restrictions

Co-administration is formally contraindicated with Monoamine Oxidase Inhibitors (MAOIs) due to the high risk of severe hypertension. This restriction includes a mandatory timing separation rule, requiring that Amfepramone must not be administered during or within 14 days following the use of an MAOI. Furthermore, the concomitant use with other anorectic agents is strictly contraindicated. This prohibition covers all other prescribed appetite suppressants, as well as over-the-counter preparations and herbal products used for this purpose.

Pharmacodynamic and Efficacy Interactions

The regulatory documentation notes several pharmacodynamic risks:

  • General Anesthetics: Concurrent use carries a documented risk for the development of arrhythmias.
  • Antihypertensive Drugs: Amfepramone may interfere with the effect of certain antihypertensive agents, such as guanethidine and alpha-methyldopa, and may cause additive pressor effects with other drugs that increase blood pressure.
  • Antidiabetic Drugs: The drug's use may alter the dose requirements for antidiabetic medications, including insulin.
  • Phenothiazines: Co-administration may antagonize the anorectic effect of Amfepramone.

Caution is advised in the official documentation regarding the concomitant use of alcohol and other CNS-active drugs.

Mechanism of Action

Mechanism of Action: How Regenon Works

Regenon (Amfepramone) is a sympathomimetic amine that exerts its primary action by targeting presynaptic monoamine transporters in the central nervous system. It functions as both a releasing agent and a reuptake inhibitor for the neurotransmitters norepinephrine and dopamine . This dual action rapidly increases the concentration of these monoamines within the synaptic cleft.

This enhanced monoaminergic signaling is concentrated in the hypothalamus, a brain region involved in governing homeostatic functions. The modulation of signals within this area alters the balance between hunger and satiety, resulting in the suppression of the appetite drive.

Furthermore, the central increase of norepinephrine leads to a heightened Sympathetic Nervous System (SNS) outflow. This engagement of the body's autonomic system has physiological consequences, including changes to the cardiovascular system and an increase in thermogenesis and metabolic activity.

Dosage and Administration Information

The administration of Regenon (diethylpropion hydrochloride) must strictly follow the official instructions for use as prescribed by a healthcare provider.

Official Administration Guidelines

The medicine is available in two oral forms, each with a distinct dosing schedule. It is intended for short-term use, typically only a few weeks.


Administration Component Immediate-Release (IR) Tablets Extended-Release (ER) Tablets
Route of Administration Oral Oral
Dosing Schedule 25 mg three times per day 75 mg once per day
Timing in Relation to Meals Take 1 hour before meals Take once a day in midmorning
Special Procedural Steps A fourth dose may be prescribed in the mid-evening if needed for nighttime hunger. Swallow the tablet whole. Do not crush, chew, or break the extended-release tablet.
Missed Dose Rule Take the missed dose as soon as possible, unless it is almost time for the next dose. Do not take a double dose to make up for a missed one. Take the missed dose as soon as possible, unless it is almost time for the next dose. Do not take a double dose to make up for a missed one.
Age-Group Rules Use is not recommended for children 16 years of age and younger. Use is not recommended for children 16 years of age and younger.

Procedural Structure

The official instructions establish a standardized, short-term protocol for the drug's use. The time of day for administration is strictly defined to manage the drug's intended effects and minimize disruption to the patient's normal sleep cycle. Consistent compliance with the route and prescribed schedule is mandatory, and the drug must be discontinued if a satisfactory weight loss (e.g., at least 4 pounds) is not achieved within the first four weeks of treatment. The maximum recommended dose must not be exceeded in an attempt to increase the effect.

Recent Clinical Evidence

Research evidence / Overview of studies for Regenon

Evidence for Use in Exogenous Obesity

This section presents an overview of the research that has been conducted on Amfepramone (also known as diethylpropion), which was studied for its use alongside a reduced-calorie diet and increased physical activity plan relevant to the study of Exogenous Obesity. The study populations primarily consisted of adults who met specific criteria for overweight or obesity (BMI 25 kg/m^2 or 30 kg/m^2).

The core evidence includes Randomized Controlled Trials (RCTs), where research compared participants who were administered the study drug versus those who received an inactive substance (placebo). These formal trials are synthesized in subsequent systematic reviews and meta-analyses to synthesize data and explore patterns across different studies.

Trial Design: Short-Term vs. Intermediate-Term Studies

Studies monitoring the medication was observed in trials with different follow-up durations. A large portion of the research describes short-term changes, where study periods often range from approximately 4 to 12 weeks. Other studies extended the period of observation to intermediate-term intervals; studies monitored outcomes over periods of up to six months. This body of research contributes to the broader evidence landscape describing short-term changes that occur over defined time intervals.

Scientific Limitations and Remaining Uncertainties

One primary Research Limitation Frame is that the evidence quality varies across studies, with systematic reviews reporting that a substantial portion of the older trials have an unclear or high risk of bias. For this reason, the certainty remains low regarding the consistency of those findings.

Additionally, there is limited information for long-term outcomes because the follow-up durations were often short. Sample sizes were modest in some key studies, and there is known heterogeneity (variability) across the designs and methods of the existing trials. The evidence highlights what is known—and what is still uncertain—about Amfepramone's use alongside diet and lifestyle in the study of Exogenous Obesity.

Frequently Asked Questions (FAQ)

Common questions about Regenon (FAQ)

Q: Are there common withdrawal symptoms mentioned when stopping Regenon?

A: Regulatory documents indicate that prolonged use of this medicine may lead to dependence. A withdrawal syndrome has been reported in official warnings upon stopping the therapy, which may include symptoms such as feelings of depression, fatigue, and intense hunger.

Q: Is Regenon available over the counter in any country?

A: No. Official medical sources describe this medication as a controlled substance due to its classification and potential for dependence. Therefore, in most regulated jurisdictions, its sale is restricted and requires a doctor's prescription.

Q: Does the medicine lose its effect over time?

A: Official product information addresses the possibility of tolerance developing, which is when the medicine’s effect decreases over time. If tolerance occurs, the guidelines state that the drug should be discontinued rather than attempting to increase the dose beyond the recommended level.

Q: How quickly do people typically notice an effect from Regenon?

A: Studies and official information indicate that patients should expect to see some initial weight loss soon after starting this medication. The procedural guidelines define a satisfactory initial response as a minimum of 4 pounds of weight loss within the first 4 weeks, after which treatment may be re-evaluated.

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

A: The drug has moderate interaction potential with certain medications, including some non-prescription pain relievers. This combination could potentially increase the risk of cardiovascular side effects, such as hypertension (high blood pressure).

Q: Can Regenon cause headaches?

A: Yes. According to the official lists of adverse reactions, headache is listed among the possible common side effects reported by users of this medicine.

Q: What is the half-life of the active ingredient in Regenon?

A: The half-life of a drug refers to the time it takes for half of the dose to be cleared from the body. Official clinical pharmacology data estimates the plasma half-life of the active metabolites of Regenon to be approximately 4 to 6 hours.

Q: Does the effectiveness of Regenon depend on the user's BMI?

A: Official guidelines indicate that the medicine is typically used in patients who meet specific starting Body Mass Index (BMI) criteria alongside other risk factors, as an adjunct to weight loss treatment. The drug is not recommended for all individuals.

Q: Why are exercise and diet often required alongside Regenon?

A: Official documents define this medicine as a short-term 'adjunct,' meaning it is only a supporting element. It is indicated for use alongside a comprehensive regimen of weight reduction that must include specific caloric restriction, exercise, and behavior modification. The product labeling states that the medication is not intended to be used as a replacement for necessary lifestyle changes.

Q: What warnings exist regarding driving or operating machinery while taking Regenon?

A: Official warnings state that the medicine may impair a person's ability to engage in hazardous activities. These activities include operating machinery or driving a motor vehicle, due to potential effects on the central nervous system.

Q: Are there specific food items or drinks that interact with Regenon?

A: Regulatory documents advise caution regarding the interaction of this medicine with certain common drinks and food components. For instance, consuming large amounts of food or beverages that contain caffeine, such as coffee, tea, or chocolate, may increase the likelihood of side effects.

Q: How is the active ingredient in Regenon metabolized by the body?

A: Pharmacological information states that the drug is rapidly absorbed and undergoes extensive metabolism (breakdown) through chemical processes like N-dealkylation and reduction. The resulting metabolites are primarily processed and eliminated from the body by the kidney.

Q: Are there restrictions on using Regenon for people with diabetes?

A: Caution is advised for patients with diabetes mellitus. The use of this medicine may alter the body's requirements for antidiabetic medications, including insulin. This may necessitate monitoring and dose adjustment.

Q: Is Regenon meant to be the only step in a weight-loss program?

A: No. Official documents clearly indicate that this medicine is intended only as a short-term adjunct. It is prescribed solely to assist with appetite control as part of a comprehensive weight-loss program that must involve specific changes to diet, exercise, and behavior.

Q: Does the manufacturer of Regenon provide a patient leaflet?

A: Yes, official patient information (such as a Patient Information Leaflet or Patient & Caregiver Education sheet) is typically provided by manufacturers and healthcare systems. This material helps users understand key facts about how to take the drug and what side effects to watch for.

Q: How does the structure of Regenon compare to amphetamines?

A: The drug is classified as a sympathomimetic amine. Its pharmacologic activity, which includes its action as a central nervous system stimulant and in appetite suppression, is reported to be qualitatively similar to that of prototype amphetamines.

Q: Are there any known allergic reactions associated with Regenon?

A: Official contraindications prohibit the use of this medicine in patients with a known hypersensitivity to sympathomimetic amines. Allergic reactions, such as rash, hives, or swelling, have also been reported rarely in the official adverse events lists.

How should Regenon be stored and disposed of?

Official Storage and Disposal Requirements

Regenon (Amfepramone) is a Schedule IV Controlled Substance, and its storage and disposal must strictly comply with regulatory requirements to prevent diversion and maintain product quality.

Requirement Area Official Constraints
Storage Conditions Store at controlled room temperature, protected from excessive heat, moisture, and direct light. The product must be kept from freezing and should not be stored past its expiration date.
Security & Packaging The medication must be kept in its tightly closed container and stored in a safe, secure place to protect it from theft. It is mandatory to keep the product out of the sight and reach of children.
Disposal Protocol The preferred method for disposal of unused or expired product is a drug take-back program or mail-back envelope. If this option is unavailable, the medicine must be mixed with an undesirable substance (e.g., used coffee grounds) and placed in a sealed container before discarding in the household trash. The product must not be flushed down the sink or toilet.

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

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