Yes...this seems to be becoming more and more common. I used to be able to take mass quantities of AAKG and related compounds, but now they just make me nauseous.
I have a hypothesis WHY this is true, and as soon as NOxidant samples arrive I will be testing it out.
Could also be upregulated PDE enzyme activity, which can cause nausea and headaches as a side effect.
How long have you been taking NO products?