Regumate

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Regumate

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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 Regumate

Property Description
Active ingredient Altrenogest
Form Oral solution (in oil vehicle)
Pharmacological class Progestogen (Progestin)
Common use Estrus synchronization/suppression
Origin Synthetic steroid (19-nortestosterone derivative)

Defining Regumate: Classification and Composition

Regumate is the established trade name for a specific veterinary drug whose sole active ingredient is Altrenogest. This compound is classified within the pharmacological class of progestogens, also referred to as progestins, meaning it mimics the function of the body’s natural hormone, progesterone.

Altrenogest is a potent, synthetic steroid derived from the 19-nortestosterone chemical family, recognized for its reliable hormonal activity. As a single-ingredient product, its structure (Allyltrenbolone) allows it to act as a highly selective agonist of the progesterone receptor. This mechanism enables the drug to maintain a strong, stable progestational effect that is critical for controlled reproductive management.

Altrenogest's Pharmaceutical Form and General Purpose

Regumate is supplied as an oral solution where the Altrenogest is dissolved in an oil vehicle, which is intended for oral administration via the mouth. The use of an oil solution as the dosage form is essential for ensuring effective systemic absorption of the lipophilic synthetic steroid.

The general purpose of administering this progestin is to gain controlled management over reproductive cycles, particularly in female horses and pigs, a practice confirmed by its classification under the ATCvet code QG03DX90. By reliably causing the temporary suppression of estrus (heat), Altrenogest provides the capability to synchronize the reproductive state across multiple subjects for scheduled breeding programs.

Regulatory References

  1. Altrenogest - DailyMed (Regumate/Altren Label)

What side effects are possible with Regumate?

Possible Side Effects and Safety Information

Regumate contains the synthetic progestogen Altrenogest. The safety profile for humans is officially documented in the context of accidental exposure to the veterinary product, primarily through skin absorption, which can lead to adverse events consistent with the effects of a potent hormonal agent.

The regulatory documentation does not classify these human effects using standard frequency terms (e.g., common or rare); rather, they are listed as Reported Human Effects from Exposure.


Reported Adverse Reactions by System-Organ Class

The reported effects following accidental contact involve several body systems:

  • Reproductive System Disorders (Female): Abnormal or absent menstrual cycles, uterine cramping, changes in uterine bleeding, and prolongation of pregnancy.
  • Reproductive System Disorders (Male): Decreased libido.
  • Gastrointestinal and General Disorders: Nausea, vomiting, diarrhea, abdominal pain, fever, and headaches.
  • Skin and Subcutaneous Tissue Disorders: Rashes.

Serious Safety Signals and Handling Restrictions

The label highlights potential serious adverse reactions, including the disruption of the menstrual cycle and the prolongation of pregnancy. The regulatory safety framework places strict constraints on handling the product.

Specific populations are advised not to handle the product due to the risk of absorption and subsequent hormonal effects. These include women who are or may be pregnant, women of childbearing age, and individuals with a history of blood clots or clotting disorders, certain cancers (e.g., breast cancer), liver disease, or a history of heart disease or stroke.

Additionally, the official profile notes that continued daily exposure poses a greater risk for more serious effects compared to a single acute exposure.

Overdose and Emergency Response

The regulatory guidance for Regumate (Altrenogest) overdose is focused primarily on the documented risks associated with accidental human exposure to the liquid product, detailing specific manifestations and required immediate emergency actions.

Required Emergency Actions

If the Altrenogest oral solution is swallowed, official labeling mandates that users seek medical attention immediately. Due to the oil base of the product, there is a documented risk of pulmonary damage if the solution is aspirated; therefore, it is stated that vomiting should not be induced and must be supervised by a physician. For accidental dermal contact, spillage on the skin must be immediately washed off with soap and water. Medical care must be sought if any adverse effects become apparent following exposure.

Documented Manifestations

Symptoms following exposure are chiefly related to the drug’s progestogenic activity or acute systemic effects. Acute manifestations may include headaches, nausea, vomiting, fever, abdominal pain, diarrhea, and rashes. Continued exposure is officially associated with disruption of the reproductive cycle, specifically documented as abnormal or absent menstrual cycles and uterine cramping in women, and decreased libido in men. The label strongly advises that pregnant women or women who may be pregnant should not handle the product.

Therapeutic Uses of Regumate

What Regumate Treats — Main Uses and Benefits

Regumate (altrenogest) is commonly used for its supportive benefits in managing the mare's reproductive cycle and providing symptomatic relief from the associated behavioral changes. It is applied in scenarios where symptoms related to systemic imbalance cause noticeable interference with performance, handling, or breeding plans. The drug is relevant for the symptomatic management of estrus in mares. This includes addressing the behavioral signs of heat and assisting with the management of the reproductive cycle. This treatment is generally used to suppress estrus in mares.


Behavioral Stability and Temperament Control

This domain is used for managing symptom clusters that may become intense or disruptive, specifically related to the estrus cycle. Regumate helps address pronounced irritability, moodiness, and distraction in mares. The treatment offers symptomatic support, helping to manage symptoms that interfere with daily comfort, which is commonly used for mares in performance or training.

“The treatment offers symptomatic support, helping to manage symptoms that interfere with daily comfort.”

Quick Fact: Support for Behavioral Symptoms


Estrus Cycle Synchronization and Management

The medication is relevant in clinical settings where the management of reproductive timing is appropriate. It is used to suppress or assist with the reproductive cycle, enabling planned breeding or embryo transfer, and is applied in addressing prolonged or erratic heat periods common during the seasonal transition. This assists with maintaining functional stability.

Regulatory References

  1. U.S. Food and Drug Administration (FDA) DailyMed entry

Eligibility and Restrictions for Use

Regumate (altrenogest) is specifically indicated for suppression of estrus in mares, allowing for scheduled breeding. Its use is limited to veterinary applications and should only be administered by or on the order of a licensed veterinarian.

Who Can Use Regumate?

  • Mares: Specifically, mares that are in diestrus or in the transitional period between the non-breeding and breeding seasons.
  • Veterinarians and Trained Personnel: Only individuals with proper training and protective equipment should handle and administer the product.

Who Cannot Use Regumate?

Regumate is contraindicated and must not be used in certain animals and, critically, by certain human groups due to its potent hormonal nature (a progestin).

Category Specific Contraindication
Mares Mares with a history of uterine inflammation or infectious conditions (e.g., endometritis)
Humans Pregnant women, women who may be pregnant, and individuals with a history of thrombophlebitis or thromboembolic disorders

Special Consideration: Because altrenogest can be absorbed through the skin, direct contact with the drug should be avoided by all handlers, particularly women of childbearing age, pregnant women, and adolescents. Protective gloves and clothing are mandatory during handling.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents detail the interaction profile for the active substance, altrenogest, focusing on its use in the target species. The information provided is generally limited, citing a specific interaction with one medicine used to treat fungal infections.


Documented Drug-Drug Interaction

Interacting Product Category Specific Interacting Medicine Interaction Statement Classification
Antifungals Griseofulvin Griseofulvin may alter the effects of altrenogest when administered concurrently. Clinically relevant

Summary of Interaction Profile

The regulatory labeling for this progestin specifies that concurrent administration of the antifungal medicine griseofulvin may modify the product’s effect. While the official regulatory texts do not often detail the precise mechanistic basis, this interaction is likely due to the enzyme-inducing properties of griseofulvin, which could increase the metabolism and clearance of altrenogest. Apart from this specific warning, regulatory documents explicitly state that there are no other known incompatibilities with other medicinal products. The profile is highly focused, noting only this single, specific drug-drug interaction for the product when used in the intended species.

Mechanism of Action

Selective Agonism of the Progesterone Receptor

Altrenogest acts as a selective agonist (activator) of the nuclear Progesterone Receptor (PR). This binding mimics the biological function of endogenous progesterone, initiating a sustained molecular signal that is central to reproductive axis modulation.

Central Modulation of the HPG Axis

The sustained receptor activation establishes a strong negative feedback mechanism on the Hypothalamus and Anterior Pituitary. This feedback suppresses the cyclical secretion of Luteinizing Hormone (LH), thereby preventing the LH surge required for the final maturation of the ovarian follicle and the subsequent release of the egg.

Functional Suppression of Ovarian Cyclicity

By blocking the necessary pre-ovulatory hormone release, the mechanism inhibits ovulation and places the reproductive system in a sustained, anovulatory state. The continuous progestational signal functionally suppresses estrus behavior, resulting in the maintenance of a stable reproductive state.

Dosage and Administration Information

The administration of Regumate (altrenogest) is based on a standardized, daily oral regimen determined by body weight, and it is supplied only as a 2.2 mg/mL oral solution. The official dosage is specified at 1 mL per 110 pounds of body weight (0.044 mg/kg altrenogest) and must be administered once daily.

The full, consecutive treatment course varies depending on the regulatory region. In the United States, the regimen is defined as 15 consecutive days, while documents from European and UK regulatory authorities detail a 10-day administration period. The entire prescribed course must be completed to ensure the expected, predictable occurrence of estrus following withdrawal of the drug.

The administration procedure is strictly limited to the oral route. The accurately measured dose—obtained using a luer lock syringe or specific dosing device—is delivered either directly onto the base of the mare’s tongue or mixed thoroughly into a single portion of the mare’s usual grain ration. Official usage guidelines further note that treatment is generally initiated in mares that already possess active ovarian function (follicles ge 20 mm) to support the establishment of regular cycles post-treatment.

Recent Clinical Evidence

Recent Clinical Evidence for Altrenogest

Regumate, whose active ingredient is altrenogest, is a synthetic progestin primarily studied and approved for use in certain female animals, specifically mares and gilts (female pigs). The clinical evidence base focuses almost exclusively on the application of altrenogest for reproductive management in these species.


Primary Research Findings in Mares

Clinical trials involving mares consistently show that a daily oral regimen of altrenogest can suppress estrus (heat) behavior. This suppression is typically observed in approximately 95% of mares within three days of starting treatment. The withdrawal of the drug generally leads to a predictable return to estrus within four to five days.

  • Estrous Cycle Synchronization: Evidence supports the use of altrenogest to control the timing of the estrous cycle, which facilitates scheduled breeding and aids in the management of mares exhibiting prolonged estrus during the transition phase between seasons.
  • Ovarian Activity Response: The post-treatment reproductive response is observed to depend significantly on the mare's ovarian activity at the start of treatment. Mares with active ovaries (follicles ge 20 mm in diameter) commonly respond with regular post-treatment cycles, while those with inactive ovaries may not.
  • Behavioral Management: Studies suggest that suppressing estrus with altrenogest may help to alleviate moodiness and temperament changes in mares associated with the reproductive cycle, which can be a factor in performance and handling.

Research in Other Species and Safety Context

Studies in gilts have also demonstrated that altrenogest can be used effectively for estrus synchronization, which assists in managing breeding schedules. Furthermore, research in pigs indicates that altrenogest supplementation during early pregnancy may be associated with improved reproductive outcomes, such as an increase in the number of total piglets born alive, though results in this area have been noted as sometimes conflicting.

Important Safety Note: Regulatory agencies, including the U.S. FDA, have issued safety alerts regarding the need for strict adherence to protective measures when handling altrenogest. This is due to the drug being readily absorbed through human skin, which has been reported to cause adverse effects in exposed individuals.

Frequently Asked Questions (FAQ)

Common questions about Regumate (FAQ)


Q: How quickly does Regumate start working after I begin taking it?

Official information indicates that the desired effect—the suppression of estrus (heat)—is typically observed quickly. Clinical trials show that this suppression is noted in approximately 95% of the animals within three days of starting the standardized treatment course.


Q: What happens if I stop using Regumate suddenly?

The Regumate treatment is specifically designed to allow for a predictable return to estrus (heat) following the final dose. Studies show that estrus generally returns within four to five days after the product is stopped, which is key to managing reproductive cycles.


Q: What are the most common reported side effects of Regumate?

Official documents do not list common side effects for the intended species (mares) using standard frequency terms. The product information notes that the drug is contraindicated (not to be used) in animals with pre-existing conditions like uterine inflammation ( endometritis), due to the possibility that the condition could be worsened.


Q: What are some less common but serious side effects listed in official sources?

Official product information for the target species notes that the drug is associated with a risk of uterine infection. For humans, accidental exposure may cause serious hormonal effects such as the disruption of the menstrual cycle or the prolongation of pregnancy.


Q: Are there long-term effects of Regumate mentioned in safety documents?

Official safety warnings state that continued daily exposure to the product in human handlers poses a greater risk for serious effects compared to a single acute exposure. These warnings focus on the serious effects that can arise from chronic, accidental exposure to a potent hormonal agent.


Q: Is there a maximum time length that Regumate is studied for use?

The standard duration of the treatment course is specified and varies by region, for example, 15 consecutive days in the United States and 10 days in some European countries. This regimen is defined by regulatory agencies for its intended use.


Q: Can Regumate interfere with fertility or reproductive health outside of its intended use?

The drug's function involves modulating reproductive cycles by suppressing estrus and inhibiting ovulation. Official safety documents state that accidental human exposure may cause impaired fertility and adverse reproductive effects like abnormal menstrual cycles in women.


Q: Can Regumate affect my other hormone levels?

Official scientific summaries describe Altrenogest as primarily having progesterone-like and anti-gonadotrophic effects. Beyond this, the compound is also described as exhibiting weak oestrogenic, anabolic, and androgenic effects.


Q: Is it true that Regumate has restrictions for pregnant people?

Official safety warnings state that pregnant women or women who may be pregnant should not handle this product. This restriction is due to the risk of accidental skin absorption, which could potentially cause hormonal disruption and lead to the prolongation of pregnancy.


Q: Is Regumate approved for use in all countries?

The product is officially approved and regulated for veterinary use in several major regions, including the United States (FDA), the United Kingdom (VMD), and the European Union (EMA).


Q: Can Regumate affect blood pressure or blood sugar levels?

While the product label does not explicitly list changes to blood pressure or blood sugar as direct effects of exposure, some hormonal agents in the same class have been associated with issues like impaired glucose tolerance.


Q: Does official guidance say about overdose of Regumate?

Official regulatory guidance focuses on accidental ingestion by humans. In this event, the official guidance for handlers is not to induce vomiting and to seek medical attention immediately. The product packaging should be brought along if possible.


Q: Is it possible to have an allergic reaction to Regumate?

Reported human effects from accidental exposure include certain skin problems, such as rashes. However, official documents do not generally list allergic or hypersensitivity reactions as a known effect in the primary target species.


Q: Is it normal to feel a change in mood or energy while using Regumate?

The product is used to manage behavioral symptoms associated with the reproductive cycle in mares. While accidental human exposure can lead to general symptoms like headaches or fever, the label does not explicitly mention changes in mood or energy levels as reported effects.


Q: Why is Regumate sometimes mentioned in veterinary contexts, and how does that relate to human use?

Regumate is designated as a veterinary drug, and its use is restricted to licensed veterinarians or their order. Its relevance to human safety is addressed through specific warnings and handling restrictions, which are designed to prevent accidental hormonal exposure.


Q: How is the research evidence for Regumate generally described?

Clinical trials supporting the drug's use are described in official documents as being extensive. The evidence indicates the drug’s effectiveness in suppressing estrus and facilitating the animal's return to regular reproductive cycles.


Q: Can Regumate be used in people with kidney or liver issues?

People with known liver dysfunction or disease are explicitly listed as individuals who should not handle this product. This safety restriction is due to the potential risks associated with the accidental absorption and processing of the potent hormone.


Q: Is there general information about what happens after the course of Regumate is finished?

The entire treatment course is aimed at enabling a predictable occurrence of estrus (heat) after the drug is withdrawn. This process is expected to help the animal return to regular, controlled reproductive cycles.


Q: How does Regumate being a hormone relate to its overall safety profile?

The safety profile is directly tied to the fact that Altrenogest is a potent hormonal agent, specifically a progestin. This hormonal activity explains why accidental human exposure may lead to serious effects, such as the disruption of the menstrual cycle.

How should Regumate be stored and disposed of?

How to Store and Dispose of Regumate?

Regumate (altrenogest) oral solution must be stored under specific regulatory controls to maintain its stability. The product must be kept at or below 25°C (77°F) and must be strictly protected from freezing. While brief excursions up to 40°C (104°F) are permitted, the solution must always be stored in its original container and kept tightly closed.

Stability and Safety

Condition Regulatory Requirement
Shelf-life After Opening Use within 14 or 28 days (depending on volume)
Child Safety Keep out of the reach of children

Disposal

Disposal of unused or expired product must be done in accordance with local requirements. The medicine should not be disposed of via household waste or wastewater, as altrenogest may pose a risk to aquatic life.

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

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