How To Mix Feline Birth Control


If you are using human Liquid MegAce, then you will need to follow the guidelines below. The most common bottle of liquid human MegAce contains 40mg/ml of megestrol acetate. That means 40 mg of MA is in each ml of MegAce. The standard size bottle of human MegAce is 240ml per bottle.


You will need the following to mix up a bottle of feline birth control:


7 ML of distilled water


1 ML of liquid human MegAce


A sterile dark/amber bottle to store solution in


A needleless syringe to measure ML

Step 1: Pour 7 ML of distilled water into a clean sterile bottle


Step 2: Using the needleless syringe, draw up 1 ML of the MegAce


Step 3: Squirt the 1 ML of MegAce into the 7 ML of distilled water & shake well.


You have now created a liquid suspension that contains 40 mg of liquid MA. Remember, each ML of the liquid MegAce contains 5 mg of MA.


Since you added 1 ML of MegAce to the 7 ML of distilled water, your final product is one which is 8 ML of liquid containing 40 mg of MA.  Each ML of this solution contains 5 MG of megestrol acetate. (40 mg divided by 8 ml = 5 mg per ml.)


Shake this solution well before each use as the MA tends to settle. You are now ready to dose your feral cat colony using this liquid suspension that you just created.


Use the chart below for proper dosing of the liquid suspension. DO NOT OVERDOSE! Use an accurate syringe (no needles!) with ml markings to be sure of accuracy. Follow the chart below exactly!





Dosing Chart For Feral Colonies Using Generic Liquid MegAce 40 mg Strength Diluted With Distilled Water. Suspension Is Diluted To 5 MG MegAce Per ML (7 Parts Water to 1 Part MegAce)



    Total Number of Cats in the Colony - Dosage per colony / Frequency

< 5 cats  0.5 ml ONCE A WEEK  (Note the decimal point here! 0.5 ml-NOT 5 ml!)

5-7 cats   1.0 ml ONCE A WEEK

8-11 cats   1.5 ml ONCE A WEEK

12-15 cats   1.0 ml  TWICE A WEEK  

16-19 cats   1.5 ml  TWICE A WEEK  

20-23 cats   1.6 ml  TWICE A WEEK  

24-27 cats   2.0 ml  TWICE A WEEK  

28-31 cats   2.2 ml  TWICE A WEEK  

32-35 cats   2.5 ml  TWICE A WEEK  

36-39 cats   2.8 ml  TWICE A WEEK  

40 + cats   3.0 ml  TWICE A WEEK



NOTE: This medication MUST be mixed in CANNED cat food and served on multiple plates or dishes (NO PAPER).  Use one 5.5 oz can of cat food for every 3 cats in your colony.   It is very important to spread it out on as many plates as possible so the entire colony is being medicated as evenly as possible.


2)    Shake the bottle of medication vigorously as the MA/OvaBan settles to the bottom.  It is very important that the MA/Ovaban/Nonovulin is mixed thoroughly before dosing to avoid under/overdose. Divide the appropriate dose of medication for your colony evenly among the plates of food and mix it thoroughly into each plate of food. 




4)    Store medication with bottle tightly capped in a cool, dry place away from sunlight.


5)    Wash syringe with dish soap and water. Rinse thoroughly.  Allow syringe to air dry on a paper towel.


6)    DO NOT SKIP OR MISS A DOSE!  If you were unable to dose the cats on your scheduled day, do so on the very next day and resume your schedule the following week. For colonies that require a frequency of 2 times per week, the dosages MUST be spaced out.   


Use ONLY distilled water. The shelf life of the liquid suspension once mixed is about 2 years if kept out of sunlight and at a cool temperature. Remember to always shake well before each use. If you are using liquid MegAce rather than tablets to make a solution, you do not have to worry about molding issues that some experience with using tablets for mixing.









Mix your own feline birth control using liquid human megace