> MDMA is also quite toxic in long-term usage.

As well as ibuprofen is. Whatever a drug (in both meanings of the word) one should decide with reason when, how much and why take it. I can hardly name a medicine which won't do any harm if you take it chronically or dose too high.

Even plain serotonin, which can be kept elevated by chronic excess of tryptophan in the diet (let alone 5-HTP supplementation) is cardiotoxic.

BTW I've chosen to mention ibuprofen right because it's harmless unless you are taking it for too long. Nevertheless I believe its common alternative - paracetamol (acetaminophen) ought to be mentioned as it's plain deadly and can be considered much more dangerous (in terms of how easy it is to harm yourself severely) than MDMA.

MDMA works by dumping serotonin out of cells, not by blocking re-absorption. It's why MDMA has much stronger effects than SSRIs.