It worked from the first time I used it. I love the way it sticks nicely to the body and how easy to peel it off.lasts longer than the rub and works great.Its the bestI can't say for sure if the patches work or not.Here is why.I'm suffering from shoulder pain that comes and goes often, and my doctor is trying to figure out what triggers it.When the pain was back, I've used the patch and kept it for 8 hours (a maximum time).While the patch was on, I still had the pain, but an hour after I removed the patch, the pain was gone.Was it due to the patch? Most probably yes, but since the patch was not there, I can't swear by it.The product has medicated ingredients: Capsaicin 0.002% and Menthol 0.39%, so it does a certain job to reduce pain.My conclusion: worth to give it a try.Ingredients:Medicinal Ingredients:Capsaicin 0.002%, Menthol 0.39%Non-Medicinal Ingredients:Disodium EDTA, Gelatin, Glycerin, Polyvinyl Alcohol, Sodium Polyacrylate, Tartaric Acid, Tocopherol Acetate, Water.How to use:Adults and children 12 years and older:Strip off the protective plastic backing, and place adhesive patch over the affected area.Change patch 1 or 2 times a day.Discard patch after each application.Non-flushable.Do not leave on skin for more than 8 hours.Children under 12 years:Use only upon advice of a physician.Going to be upfront. This doesn't help at all. It is neither hot nor cold. Im not sure what this does for my lower back pain. It does take a good 10 minutes to start feeling something but mostly it feels cool sensation. Its a fairly large patch which is nice. It's a gooey adhesive that sticks on good to your back. It does smell bad... I'm not a fan of the smell.I'm not able to understand why this is superior to ice bags and heating pads. I guess if you're going to need it at work , then this might be a gentle alleviation during the day... For that , perhaps that is OK.4-stars for value for money. Each patch costs about $2.25, so it isn't cheap.5-stars for performance. My wife always complain of back aches. We have already used a couple of these on her back and she is happy with the performance. It starts cold, and slowly starts warming up after a minute or so. The warmth provides a nice healing effect and helps reduce the stress/pain. It is not a permanent solution for aches, but it definitely provides excellent short term relief.My father occasionally has recurring lower back pain, most likely stemming from a disk problem. The last time he felt some moderate pain in the area, he tried these Rub-A535 Back Pain Relieving Ice to Heat Patches. Unfortunately, they were mostly ineffective at helping him cope with the pain. He said that whatever modest relief he felt was gone within one hour of applying these patches. The active medicinal ingredients in products - menthol and capsaicin (chilli pepper extract) - are most likely insufficient for people with moderate to severe back pain. It will likely depend on the source of the pain too. Instead, my father uses Voltarin and products containing lidocaine as these agents are effective at treating his condition. This product is probably good for people with very mild muscular pain or the type of pain after vigorous exercise. I would not recommend this for people with any type of moderate to severe chronic pain, however.I was very skeptical about the efficacy and pain management that I would get from the Rub-A535 Back Pain Relieving Ice to Heat Patches, but was pleasantly surprised that there was some relief from these easy to use patches. I tried them on several spots on my back, and found that the pain relief was for about 7 hours. The only thing I didn't like was that in some spots they stayed on better than others, especially where there was rubbing from clothes. Other than that, these are great.