Do not worry about it too much. It is just normal. Try to ask 100 users of mt-2 and most of them will tell you that they have already experienced the same case when it was their first time to use it.
Dear, it is just normal. Do not freak out about it. Anyway, in the long run, you will no longer experience it. I think every mt-2, hgh and peptides user has experienced the same thing.
Fast heartbeat is normal unless the fast heartbeat continues for months. Do not be so afraid of it. it is just normal knowing that your body is still shock from what you have administered.
I hate to admit it, but it has been a common side effect for those who are first time users or newbies. I also experienced fast heartbeat during my first administration. Fortunately, I got used to it and now, I no longer get it.
I think this effect is normal. This is not just a case for melanotan. It is a case for most peptides and hgh available online these days - not because they are dangerous or what. This is just really a common side effect that does not last long.