Boners last a long time but cant seem to finish. Gramps, I take two at a time also (2 50's). I get a totally red face and very flush. No other sides (headache, cramps, or blue vision). When I take 50mg, not much seems to happen. I get my usual boner. But at a 100mg, I can pee with a full boner, it wont come down for anything.