FWIW, here’s a few tips from my experience. First, plugging is not even close to IV. It’s a great method though, all ROAs (routes of administration) except IV have a slightly different come up but a similar high in the end. It’s always good to rotate your ROAs to give your body parts a break.
I find there’s a sweet spot with dosage beyond which it becomes exponentially harder to stay hard. That’s an amount you’ll have to personally figure out. If you take too much, you’re better off to take a break than to keep endlessly trying. You get desensitized after hours of trying and it becomes futile. Believe me, wait a couple hours and you’ll notice the difference. Personally, I find the sweet spot is about 12 hours after taking a bit too much (more than a point). Take it in the morning, then wait the 12 hours and that night take a small bump and go at it. It will be mind blowing. A little Viagra will also help things along if necessary, there’s no danger that I’m aware of with that. Good luck and have fun!