Do you get dependent on them? If you take a couple, do they fix your imbalance or would you have to take them everyday? How is it different to MDMA in its serotonin use, will I feel like shit the next day if I take a supplement like I do when I take MDMA? What are the side effects? Do you like them?
I personally don't like them. They make me really aggressive and moody. 5-HTP is the precursor to serotonin, 5-HT (your body turns 5-HTP into serotonin). Taking 5-HTP will only increase your serotonin levels. People usually take it after MDMA to try and restore some of the lost serotonin. Some people also try to make their MDMA experience more pleasing by "loading" on it before they take the MDMA. Taking just a couple should restore serotonin to its terminal buttons/synaptic vesicle. I don't really like them personally. I would only take 1 or 2 after a MDMA dose to try and get back to normal.
Take 100mg of 5htp before you take MDMA. 5htp takes 6 hours to digest and increase serotonin levels, therefore you shouldn't feel the depressive/anxious after effects of MDMA.