It is hard for us to tell if this product actually works because we are also using a pheromone plug-in dispenser and a D.A.P. spray. This is part of our ongoing effort to calm our dogs as part of a very tedious effort to get them to quit fighting each other. (Long, expensive story.) Our board-certified behaviorist veterinarian (like I said, it's a long, expensive story) said he is very much in favor of pheromones for canine anxiety, which is sometimes related to aggression but not necessarily. Of the pheromone products on the market, he said he is especially keen on the collars, since the dog can wear one at all times other than bathing, swimming or romping in the rain. I was glad to get his opinion since we had already ordered multiple pheromone products by the time he gave us his views.
Our dogs seem to have calmed quite a bit since we unleashed all of these devices on them and our impression perhaps the product of wishful thinking, is that the collars have contributed to that calming. The collars were the last pheromone device that we added. As an experiment that might more directly test the collars, we recently put one of them on our son's storm-phobic pooch. No storm has occurred since but when it does we can see if it helps that dog. That would be a more revealing test because the collar is the only pheromone product used in our son's house.
One reason we ordered this particular collar is that is has more of the active pheromone ingredient than other D.A.P. collars such as the ones made by Comfort Zone. The collars are easy to use and the flakey stuff that coats them wears off quickly once you put them on the dog. You can cut to the length that works best, which means a length that allows for the collar to be slipped on and off without unbuckling it. Our dogs have had no adverse reactions to the collars.
One point worth making, as of this writing, is that despite what the VetDepot website says, these collars are designed to last only one month, not "two." I've called this to VetDepot's attention and they readily agreed to change their website. That was a few days ago and the incorrect info has yet to be changed. I guess it takes a bit of time.
Incidentally, VetDepot was the cheapest source of these collars that I could find and the service was fast and flawless. We've already ordered several more so that we always have one available when the old one expires.