The only real RY4 is Dekang RY4 and a lot of people say nothing on the market truly compares. Dekang manufactures RY4 for Ruyan, to this day it is available on many websites. uhmmmmm.. Here is the unofficial history of RY4, by ECF member billherbst:
"According to information unearthed here on this thread (about eight months or so back) from reliable inside sources, the original RY4 is indeed still made and sold. That was (and is) Janty Elixir RY4.
The story we got is that the first-ever no-kidding original RY4 was created literally as a lark during a single afternoon in a Dekang factory in China back in 2007 by two men: Ludo---one of the owners of Janty (who was visiting the factory because Dekang manufactured Janty's e-liquids)---and a flavor chemist, presumably working for Dekang.
The RY4 you're talking about---the now-mythic "lost" Dekang RY4---was one of numerous Dekang variations on the original Janty recipe. It was actually stolen in the summer of 2009 by a Dekang flavor chemist who was departing to start his own juice company. He was subsequently arrested, tried, convicted, and is serving a prison sentence in China. Meanwhile, the stolen recipe remains missing to this day.
So, you want the original? Buy some Janty Elixir RY4. You want the lost Dekang? It doesn't exist, although numerous attempts have been made to replicate it. I hadn't started vaping in 2009, so I never had any of the Dekang reformulation that some folks would apparently sell their first-born to have again, so I can't tell you how close the current Dekang formula or IKV RY4 Gold are. Ikenvape's was supposed to be a dead ringer, but many people who had the lost Dekang insist that it had no nuttiness at all, and IKV RY4 is definitely nutty, so who knows?"