primordial golden elixir

[RayRay]

When do we use this? I just got it. I'm Foundation Establishment Mid stage; i'm about a 25% of the way there. Does this give more cultivation or do I need to use it when I'm maxed?

[worstcase11]

I think you need it to break through from Foundation Late to Core.
(still working on that myself - once you are at FL you need another 300,000 Exp to the next stage.)