Powerful, be careful
I added one capsule worth to a smoothie of about 40 oz. Drank about 6 oz of the smoothie (therefore consumed no more than 80 mg of niacin). Maybe 10-15 minutes later - major "flushing". First the face, and then most of my body. Having heard of "niacin flushing" I googled it and found out that it was not harmful (and may be a good thing). I regularly take supplements, including B formulations. Never before experienced anything like this. After about 30 minutes, the redness started reducing. I hate to think what would have happened with a full 500 mg dose. Supposedly your body eventually gets used to the niacin, and future flushing becomes less dramatic.
If you know what you are doing, and like the flushing, this product really works. If you have no experience with taking niacin, be quite conservative with your dosing.
Easy to swallow, and you know it's working/being absorbed due to the flushing.
Its one of the few vitamins you know when its real. No time release, and not flush free, prefer it that way - you know it isnt just a chalk pill. Acts pretty fast, but depends on whats in the stomach.
great price , reasonable shipping cost and speedy delivery.