I am finding it hard to quit smoking. please advise on nicotine replacement therapy.

Blood should help!: I hope experts in nicotine also answer - but let me add this to whatever they say. A part of smoking that is actually good for you is the breath pattern. It is the best way to clear old air, lowers BP and helps us relax. So, when folk quit - they lose this. Don't! Keep doing that pattern as often and long as if you were smoking - just w/o the tobacco. It will help!