
Megestrol Acetate is available as an FDA-approved commercial tablet and as a compounded formulation, prepared by Mixlab for veterinary use in dogs and cats. Available by prescription.
The uses and pharmacology described below reflect the FDA-approved labeling for this active ingredient; your veterinarian determines whether and how they apply to your animal's treatment plan.
Megestrol acetate is a synthetic progestin. On the FDA-approved human label, it is indicated as an appetite stimulant and for certain hormone-responsive conditions.
In veterinary medicine, megestrol acetate has been used in dogs to postpone estrus and manage the effects of false pregnancy, and in cats for certain skin and behavior conditions. This information is not a substitute for veterinary diagnosis, prescribing, or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.
This medication is classified as hazardous — wear gloves when handling it, and avoid contact if you are pregnant or nursing. Reported effects include increased appetite and weight gain, and with longer use, risk of uterine changes, mammary gland changes, and adrenal suppression; in cats, rare but serious neurological effects such as seizures have been reported. Avoid use in diabetic animals and during pregnancy. Full effects may take several weeks to become apparent.
Yes. Megestrol acetate is available only by prescription from a licensed veterinarian.
Both. Mixlab can dispense the FDA-approved commercial tablet, or compound the active ingredient into an alternative strength or format if your veterinarian determines that better suits your pet's needs. The decision rests with the prescribing veterinarian.
Megestrol acetate has been used in dogs to postpone estrus and manage false pregnancy, and in cats for certain skin and behavior conditions. Your veterinarian determines whether it's appropriate for your pet.
Contact your veterinarian if you notice significant weight gain, changes in thirst or urination, mammary gland changes, or — in cats — any seizure-like activity.