Can meditation change your hormone and neurotransmitter system? Meditation can cause a lot of rest and peace. But can it also change the levels of hormone and neurotransmitters? Do they increase or decrease? I tend to think that fe your adrenaline is getting down and perhaps your testosteron. So can you become less 'male' or 'female' of it?
So far I have only one first-hand report of a practitioner diagnosed with ADD due to dopamine re-uptake problems, who says meditation helps him regulate the levels of dopamine.

From buddhist theory we know that the Four Jhanas meditation is intended to produce joy, which should correlate with the functioning of the reward mechanism of the brain, which is primarily dopamine-based. So another way to see the Jhanas, esp. the first and second one, is as mastery over one's dopamine levels by taking control of the reward mechanism.

As far the levels of other hormones and neurotransmitters, I can only assume they get "better", but there is nothing I know first-hand. A nice book on the topic seems to be Zen and the Brain: Toward an Understanding of Meditation and Consciousness but I have not read it.