I think we are in a battle of definition.
A new drug is protected from duplication by patents for 17 years after it is first patented. Extensions and combinations with other drugs can extend this term. These drugs are FDA approved after extensive testing. Viagra (sildenafil citrate), Cialis (taladafil) and Levitra (vardenafil hci) are brand names with the chemical name in parenthesis.
"Generics" are FDA approved drugs for which the patents have expired and a manufacturer has received FDA approval to sell a low price copy of the drug. Generics only have to provide similarity of contents. Generics often use different fillers, pill shapes, colors, etc but the active ingredients are the same formulation as that approved by the FDA.
Over the Counter drugs are generally generics that are considered safe for self medication. Aspirin, Aleve, Prilosec and others fall in this category.
Supplements are not drugs but other natural ingredients that are sold without testing and with all sort of bullshit claims at times. Crap like Encyte fall in this category. Incredible claims but in most cases these have no active ingredients other than caffeine or other "natural" extracts. Many diet pill fall in this category.
I don't care what crap you read on the internet, there is no such thing as "generic" Viagra, Cialis, Levitra. Viagra's patent expires in 2019, Cialis in 2017 and Levitra in 2018. Teva had applied for generic Viagra in 2013 when the original Viagra patent was to expire, but it received extensions through 2019 in the US.
Is there such a thing as "generic" Viagra, I would guess there is, but whatever you are buying is not a regulated drug and as such you can't ever be sure of its contents. There definitely is no generic Cialis or Levitra under any definition. In any case, if you are buying a legal generic drug, it will not be called Viagra, Cialis or Levitra since the market names are copyrighted. Generics are sold under the chemical name.
So there you have it. You can ignore all I wrote above since in your views I am an ignorant asshole. I wish you the best and my you never take a toxic generic that screw up you health or get that erection that lasts for over four hours.