Can I apply for a patent on this product?

How do you know it is not patented? Did you do a professional search? Sometimes professional searches cannot find patent applications since they are secret for 18 months until publication. Taking something from someone is dangerous because you might infringe, and probably will get sued when the patent application matures. Unfortunately, you can not patent something you did not invent. If in fact it is not patented and you "figured it out" how to make it, you can sell it and even profit from it, as long as you do not use its trademark name. A quick lesson, in order for an invention to be patentable you need the following: 1. that the invention be novel. New. Not known or used in the USA 1 year before filing the U.S. application. 2. that no one has a patent on the invention anywhere in the world. 3. that no one has sold the invention, or offered to sell, more than 1 year before filing the U.S. application. 4. that the invention not to be obvious (a non trivial change) 5. that you are the inventor who conceives at least one claim in the patent Trade secrets: if the there is no patent, then there might be trade secrets. You are allowed (and in fact encouraged) by the law to do two things: First, if not patented, or covered by trade secret, to reverse-engineer, this means you can go to a chemical lab and find out the composition or "figure it out." Second, if the composition is in fact patented, you can design around it. Therefore, to be in the safe side, you can always improve on the product, find out how it works, make it better (a non trivial change), and then apply for your own patent. Become a competitor with a different or improved composition. I think your issue is going to be for the improvement to be inventive enough (non trivial) worthy of a patent.

If the product you are making is structurally the same as a product that already existed then no. If you are making a chemical compound a new way then yes you may patent the way of making the compound - but not the existing compound.