I can't say if it made her act different or not, because Darcy is a rescue, and I took her to the vet within 24 hrs of my husband finding her, for excessive panting/peeing on herself.  She has congestive heart failure & he chalked the peeing up to old age. He put her on Lasik and Proin right off the bat, and she has been with us since Spring of 2008.  
 
That dose should work for her fine, since that is what I give Darcy, like I said, we had to experiment, he was doubtful it would work and I was thinking I was going to have to keep her in diapers. 
I remember the receptionist at the vet saying once that she had to log who she sold the Proin to, and she told me people used to take it lose weight?? 
