Actually nowhere near enough research has been done to understand what, if any, long-term damage frequent MDMA use can cause.<p>In the very short-term it is quite neurotoxic, and consuming too much can cause immediate problems. It looks like short-term problems can be minimised by taking a few weeks in between uses, and according to at least one study it looks like all damage can be undone by just a few months of abstience.<p>However there&#x27;s really not enough data about lasting affects, if there are any, or about how frequency of use could impact your brain&#x27;s outcome, or.... etc.<p>Anecdotally I&#x27;ve heard many stories of people using MDMA too often and &quot;losing the magic&quot;, that it just stops giving them the effects they used to enjoy.<p>One other thing to note, you wrote <i>&quot;if you keep taking it, it will stop working altogether eventually, regardless of an increased dose&quot;</i> I&#x27;m no expert, and could well be corrected on this, but I suspect that is much more the case with the positive effects than with the downsides. For example MDMA is a drug known to have a &quot;sweet spot&quot; for most people, unlike many drugs (from booze to weed to cocaine) where different people build up different tolerances&#x2F;preferences and therefore have a large range of doses, MDMA is generally thought to have quite a small range of good doses, after which increases will cause more&#x2F;worse side affects without adding anything positive to the experience.<p>Edit: <a href="https:&#x2F;&#x2F;dancesafe.org&#x2F;drug-information&#x2F;is-mdma-neurotoxic&#x2F;" rel="nofollow">https:&#x2F;&#x2F;dancesafe.org&#x2F;drug-information&#x2F;is-mdma-neurotoxic&#x2F;</a> is good for brief further reading (good sources cited at the end to follow), as well as <a href="https:&#x2F;&#x2F;www.erowid.org&#x2F;chemicals&#x2F;mdma&#x2F;mdma_neurotoxicity1.shtml" rel="nofollow">https:&#x2F;&#x2F;www.erowid.org&#x2F;chemicals&#x2F;mdma&#x2F;mdma_neurotoxicity1.sh...</a>