The over all effects are impossible to summarise, but as an introduction there are some things worth knowing and preparing yourself for.
A common initial effect is, well, not very much really. Nothing happening. Or something so subtle that you're not sure if you are just imagining it. This is true for my initial attempts at least. I have to say for the first two or three separate occasions I tried it, I was rather underwhelmed. It was by way of smoking the leaf and my first thoughts were that I was not practiced enough at the technique. I still suspect this to be the case but have since read that this ‘nothing at first’ phenomena (for whatever reason) is not at all uncommon. Other people get bowled over first time however. Whether this is the case or whether it takes a while, there is no need to kid yourself on with imagined effects. It is very real.
Having said that, the first real effects can be also be deceptive. One common physiological effect is a rise in skin temperature resulting in a hot flush. But the most deceptive effect is an initial reaction that can seem strangely and suddenly similar to drunkenness, … dizzying. The effects of alcohol provide such a common reference point that one can quite easily, through a kind of psychological reflex as it were, categorise the experience as mostly similar, and thereby at first mostly miss it. The main problem being of course that with alcohol one does not expect to have ones level of awareness raised (quite the reverse in fact) and expectation can then colour the experience. Even getting your head round this intellectually may not be enough. It takes practice to get the most out of Salvia.
If these physiological symptoms were all that there was to it, then it would not be a particularly interesting experience, not one that would encourage getting further into anyway.
I strongly recommend getting comfortably and safely seated or lying on the floor. It’s not a drug to dance to. It discombobulates the body, but it definitely quickens the mind. There's no doubt that Salvia is about the expansion of consciousness.