The nausea is usually the worst when first starting after not taking it for a while.
I am having my own issues with MT2 such as coughing up mucus and kidney pains. In fact, every single supplier I have used, except Tan Research in 2007 have caused these problems. The worst was USLabs. I went to the fucking e-room for those kidney pains. Turns out I was ok. They said I probably pulled a muscle in the gym, causing the kidney pains, lol. I figured USLabs used mannitol as a filler. Mannitol, according to Wikipedia, is a "Kidney vasodialator" among other things. Of course, every company that I've had problems with (Europatan, UsLabs, Peptide4u) all deny mannitol use. They say the peptide is "lyophilized" which means freeze-dried, and that gives it its fluffy appearance. The MT2 that gave me no harsh sides back in '07 was not lyophilized. Tan research's product, according to people on the melanotan forum, has gone downhill. The Mt2 looked like a vial with a little bit of white dust in the bottom. If anyone knows where to buy the good MT2, please shoot me a PM.