My dog was on a prescription medication before this. I had to stop her previous medication because it was out of stock for a while and when it was restocked, the price skyrocketed to $250 for a 6 month supply instead of the usual $120 that it was prior. There was a new generic version of her prescription but after reading the reviews on that, I didn’t want to risk my dog’s health. During that time of her not being on any preventative, we ended up with a flea problem in my area which we never had before. Since the fires, a lot of wildlife has been dropping by in my neighborhood and with wildlife comes fleas just hitching a ride with them. We fell victim to an infestation in our backyard and surrounding areas. I panicked and tried the holistic approach for months with DE, changing my dog’s diet, essential oils, etc to no avail. I had to try something because my dog is old and I really didn’t want to stress her by taking her to the vet for yet another prescription (which all had extremely negative adverse effects after doing plenty of research). I decided to try an OTC flea treatment and it was between this one and frontline. After doing more research, I opted for Advantix II since it was more effective than frontline (for my area). So glad I did because fleas were gone within a day. My dog has been on this for a year now and so far it is working. I did find a flea on her the other day right after we got back inside from our little walk and was able to grab it. I put it in a ziplock bag with a piece of my dogs shedded fur just to see if the treatment was still working since it had been 26 days since I used Advantix and within 2 hours of that flea crawling on her fur in that bag, it was dead. So I know for sure that this medication is working and working effectively at that. She was groomed two days prior to me finding a flea on her as well (she had a waterless bath and is wiped down with her dog wipes daily) - the bath and wipes didn’t minimize the effectiveness of this flea medication which is a huge plus! What I’ve learned throughout this whole process is that no treatment is going to immediately kill or prevent fleas or ticks - not even prescription medication - Advantix has saved me hundreds if not thousands of dollars on prescriptions and it’s still as effective as a prescription. It’s a win - win in my book and I will continue to use this year round to keep my dog protected.