Tramadol
"I work 7 days a week, 10-14 hours a day doing hard labor. my friend gave me a 100mg pill from citra (I think) one day and within 15 minutes all the pain was gone and I felt like my mood was increased x10. I worked harder than I usually do without one and had a very fast pace. I take one in the morning when I know it's gonna be a rough day and it helps me out through the whole day, if I notice I really need another one (which is rarely) I'll take half and feel better. I stop for a week or two to not build a big tolerance and haven't felt any negative side affects or having the need to want to just go pop some. The only noticeable side affect which didn't mind much was that my breathing was slightly off, not too much; most pills cause it."