I think we should avoid using this term wherever possible. It is applied to various preparations, all entirely different, and in my view none are anything like MDMA.
I agree with P_D: any State or federal drug legislation that has analogue laws renders all the first generation N#@ products illegal. Who knows about the second lot.
In terms of the query above:
As wrong as this sounds, and I do not mean to be morbid, if one were to say they ingested the "substance" to end their life they probably would not be prosecuted. If one ingested the substance to party the night away, they might be. I use this example to highlight the apparent absurdity.
In WA at least, using a prohibited drug is illegal, in the same way that possessing one is. If the substance did not contain a common prohibited drug the authorities might struggle to prove what it was that you consumed, and if they don't know what you took the analogue laws cannot be applied. It would be hard to prove one intended to take a substance to mimic the effect of a listed prohibited drug unless that substance was marketed in that way, and it would still need to be shown the punter was taking the substance for this purpose. Without being caught with the packaging or the actual substance (and then they would focus on the possession charge and forget any usage of it), it would be difficult to prove and for such a minor charge why would they bother. Things might be different if you did something else, such as kill someone in a car accident, but then you would have more problems to worry about anyway.
It also needs to be kept in mind that there is the defence of honest and reasonable mistake of
fact. If you honestly and reasonably believed that the preparation contained certain substances that are actually all legal, then you could not be prosecuted for using or possessing the substance. This is because you are mistaken about the contents of the preparation as opposed to the legality of anything contained in it.
On the contrary, a mistake of law is no defence. If you knew the contents of the preparation but did not know that a particular substance in it was illegal, then you can be prosecuted (=ignorance of the law no excuse).
If you had no idea what it contained then things get a little more complicated. However, wilful blindness and a failure to make any enquiry, particularly if the effects of the preparation are like other common prohibited drugs, might make it difficult to defend any possession or usage charge laid against you.