I think there's two ways to use it. Either you give a small dosage regularly, which is what I did with my female (I gave her 4 drops at a time, between meals, 2 or 3 times a day). In that case I think it takes a while to see an effect. For me, it took a couple of weeks. If you're anticipating a stressful event (eg fireworks, trip to the vet), or if your dog has just experienced a traumatic event, then I think you have to administer it differently (I think it's a larger dose, a few times within a shorter period of time... I saw it written somewhere, maybe on the website...). Anyways, give a shot, if you find it doesn't do much, it won't have hurt your dog in any way (just your pocketbook!!).