>>Flush free niacin is widely available (as you well know) and any physician can recommend it as part of a cholesterol lowering regimen, along with any other medication.
At least one of those was once on the VA formulary. But the VA dropped it when liver tox issues developed.
I take Niaspan (2 g's) and have for about 7 years. I regularly have the liver tests done and have had no problems. I doubt you can take 2g per day of the other slow release or extended release versions without flushing or worse - risking liver damage - no way I would take that risk.