Today's listing comes from the website LPGS.org. If you don't know what that stands for it's "Large Penis Support Group" . LPGS has a forum of user-submitted stories that I check every once in a while. With some searching you can find some real gems, such as this one.
It's a standard guy-finds-magical-growth-cream type story, but still very enjoyable. As you can probably guess from the name of the webiste, the crux of the story focuses on the guy's growing cock, although he grows all over and there are several nice muscle growth moments as well. It is a straight story, so fair warning if that's not your cup of tea.