Finding the right dose is key. I didn't know what flushing was until I took a 25 mg generic V, felt like I had a 104 degree fever concentrated in my face. After that I cut them in half, still noticed slightly elevated body temp but nothing drastic. Last few months I've been taking 10 mg generic C, biggest side effect is next day sometimes feel low level headache or body ache.
I use them to help maintain erection, don't want to lose wood halfway through the action. Being more relaxed also enables me to last longer. I'm not a 2-pop-in-an-hour guy. I've tried it's just too much work, I'm more likely to bust a hip before I bust a 2nd nut. So now I'm more of an enjoy-that-first-pop-as-much-as-possible guy. For what I'm spending on the session, a couple more dollars (prob less on avg for generic) on the meds is money well spent.