A urologist, not "my" urologist, but the penile rehab urologist in the same office that came in and visited with me when it was all first discovered who said it's been shown to help but it certainly doesn't hurt. It's essentially grapefruit extract. It's a big pill that I don't like taking because I gag on it, but I'm enjoying zero ED so if that means I have to gag on a pill, I gag on a pill 😂