But my understanding is that molly releases massive dosages of serotonin, which are sent back to other receptors, which gives a crash feeling.
mdma releases lots of serotonin, which activates serotonin receptors. the serotonin is broken down "after use" (great simplification) while mdma also slows down the synthesis of new serotonin for a while. additionally the receptors, that the brain thinks have been activated too much, are also degraded (to prevent future overactivation) and eventually replaced. likewise for the serotonin transporters used by mdma to cause the huge serotonin release.
the best thing to alleviate the crash is to not take mdma while your brain is still busy replenishing your serotonin supply and restoring its balance of receptors/transporters. also keeping your mdma dose at a minimum is helpful.
If st. john's wort is a serotonin reuptake inhibitor will it stop that from happening?
TLDR: can st. john's wort or an SSRI AFTER molly keep all the serotonin in your brain?
st. john's wort contains a complex mixture of active substances, many of which we haven't characterised yet. labeling it purely as an ssri is certainly far from the whole truth.
in contrast to typical ssris, st. john's wort does upregulate the relevant serotonin receptors, so it might be of use in that respect.
ssris should generally be more of a hindrance to recovery than a help. if you block the serotonin transporters (or reverse it like mdma does) more serotonin will be broken down instead of re-used. having more serotonin in the synaptic cleft would also lead to more receptor activation and therefore downregulation. additionally, blocked serotonin transporters are recognised by the cells as being defective and degraded, which leads to lower levels of sert rather than higher ones...
tl;dr: st. john's wort is certainly better than ssris, but could at best only help for one minor aspect of the crash (probably more for any long term consequences rather than the crash itself). also make sure you wait until the mdma is completely eliminated from your body before taking it.
