Altren® Oral Solution
Altren® is an FDA-approved preparation containing Altren, for veterinary use. Available by prescription.
How to Give Oral Solution
Oral solutions are liquid medications that you give by mouth. In a solution, the medication is completely dissolved in the liquid, so it usually looks clear or evenly colored. Here's how to give it:
- Shake well each time to mix the medication (5-10 seconds).
- Measure the dose using the syringe/dropper provided or one recommended by your vet. Insert the top of the oral syringe into the bottle adapter. Turn the bottle upside down and pull the plunger until the medicine reaches the volume required
- Hold your pet steady: a towel or helper can assist with squirmy pets.
- Administer the dose slowly into the side of the mouth. Allow small pauses if needed for swallowing.
- Raise the head slightly to help the medication go down and clean any spills with a little water or tissue.
- Praise your pet and offer a treat or water (unless advised against feeding right after).
- Clean the syringe with water immediately after use. Store the bottle as directed, out of sunlight.
- Consistency is key: Shake each time, measure accurately, and contact your vet if any issues arise.
Veterinarians most commonly consider Altren® for the synchronization of the estrous cycle in mares to facilitate breeding health and scheduled reproductive management. It is also frequently a point of discussion for suppressing estrus in mares exhibiting undesirable behavioral shifts associated with their hormonal cycle. Altrenogest is the active ingredient in Altren® and Regu-Mate®, the FDA-approved commercial oral solutions for horses. Mixlab also compounds altrenogest into alternative strengths and specialized dosage forms when a veterinarian determines a customized preparation better suits an individual patient’s needs. By providing a consistent source of synthetic progestin, your veterinarian can manage the physiological timing of a mare’s "heat" or suppress it entirely during competition or transit.
At a pharmacological level, altrenogest acts as a potent agonist at progesterone receptors. It functions by suppressing the release of gonadotropins, specifically luteinizing hormone (LH), from the pituitary gland. This suppression may help address the development of large follicles and is involved in the context of ovulation suppression, maintaining the mare in a non-receptive physiological state. Once the medication is withdrawn, the suppression of LH is lifted, allowing for a predictable return to the follicular phase of the cycle. Your veterinarian will determine the clinical appropriateness of Altren® based on your mare’s reproductive history and specific medication requirements.
The actions described here reflect the product's FDA-approved labeling; your veterinarian determines the appropriate use for your animal.
Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing or monitoring.
Commonly observed effects of Altren® in mares are minimal, though some individuals may experience transient changes in appetite or localized irritation if the medication is administered incorrectly. A critical safety consideration for Altren® is that the active ingredient, altrenogest, is readily absorbed through human skin and can disrupt reproductive cycles or hormonal balance in people. For this reason, anyone handling the medication must wear non-porous gloves, such as vinyl or nitrile and follow strict safety protocols to avoid accidental exposure. Owners should watch for any signs of skin irritation or uterine discharge in their horse and contact their veterinarian promptly if these occur.
This medication is typically used with extra caution or avoided in mares with a history of uterine inflammation (endometritis). Because of the risk of accidental human exposure, pregnant women or individuals who may become pregnant should avoid handling the medication entirely. Before starting a protocol, ensure your veterinarian has a complete history of all other prescriptions and supplements your horse is receiving. Your veterinarian is the right person to provide guidance on the necessary duration of use and the most commonly considered safety measures to ensure the management approach remains suitable for both the horse and the handler.
Yes. Altren® is an FDA-approved prescription medication and can only be dispensed by a licensed pharmacy upon receipt of a valid authorization from a licensed veterinarian. Mixlab verifies all authorizations before any medication is prepared or shipped to your stable.
Yes. While Altren® is a commercial oral solution, Mixlab can compound the active ingredient, altrenogest, into specialized strengths or alternative dosage forms—such as injectable preparations—if your veterinarian determines a customized approach better suits your horse’s needs. The decision between the commercial product and a compounded preparation rests with the prescribing veterinarian.
Altrenogest is easily absorbed through the skin and can interfere with human reproductive hormones. It is essential to wear non-porous protective gloves and avoid any direct contact with the liquid. People who are pregnant or trying to become pregnant should consult with a healthcare professional before handling this medication.
Veterinarians often discuss Altren® for mares that show significant behavioral changes or discomfort while in heat. By suppressing the hormonal shifts associated with estrus, the medication helps maintain a more consistent physiological state, which can be a clinical objective for performance or competition horses.
