Chemgasm describes the flushing like this:
At 20 minutes post-dose, it peaked. Face had flushed scarlet red, my chest was somewhat red too, little pricks of red (allergy-like) appeared on my arms and chest and face. I experienced that hot-from-the-inside feeling one gets the night after being in the sun all day. Over the next ten-twenty minutes, the flush subsided.
All this might not sound so bad compared to, say, Viagra's "priapism, severe hypotension, myocardial infarction, ventricular arrhythmias, sudden death, stroke and increased intraocular pressure".
But remember that it's early days yet, and more side-effects are going to be coming out of the woodwork pretty soon.
