The album was co-produced by Garth Richardson and Mudvayne, and executive produced by Steve Richards and Slipknot member Shawn "Clown" Crahan.

[10] After independently releasing their debut extended play, Kill, I Oughtta, the band signed to No-Name/Epic Records.

Drummer Matthew McDonough reflected, "We worked around the clock, and some of the engineers we had with us literally went for days with-out sleep.

There were songs I left alone and didn't mess with until we were in the studio, which was not a smart idea considering the time and budget constraints we were under.

[18][19] Mudvayne has found additional inspiration from artists such as Obituary,[20] Emperor,[16] Mötley Crüe,[20] Alice in Chains,[20] Pearl Jam,[20] King Crimson,[16] Porcupine Tree[16] and Metallica.

[9][14] During the songwriting process, the band members paired riffs with lyrics based on what Matthew McDonough referred to as "number symbolism".

[17] According to McDonough, while he and Chad Gray wrote the lyrics to "Nothing to Gein", Greg Tribbett performed a riff which alternated in bars of 4 and 5.

[9][17] Gein's story grabbed the attention of McDonough and Gray as they were leafing through a book on murderers and true crime.

[9] The album's title derives from the technical term 'Median lethal dose', abbreviated 'LD50', used by toxicologists to refer to the dosage of any given substance required to kill half (50 percent of) the members of a tested population.

50", composed and recorded by drummer Matthew McDonough, appears on the album as a series of interludes.

The complete piece appeared as a bonus track on The Beginning of All Things to End, Epic Records' reissue of the band's 1997 self-released EP Kill, I Oughtta.

[2] He noted the band's technical background, comparing the songwriting style to that of Nirvana and stating that the album's interludes are better than those of Slipknot.

[28] AllMusic described the music as "hard to take seriously", noting that "the CD booklet, which contains an acknowledgments section as lengthy and gushy as what you'd find on a teen pop album.

Can these guys giving thanks and love to family and friends be the same ones performing aggressive lockstep metal, spewing obscenities, and singing about suicide?

gave the album a negative review, stating that "Despite titles like 'Internal Primates Forever,' '-1,' 'Nothing To Gein,' 'Pharmaecopia' and '(K)Now F(orever)' nothing can improve this pathetic nu-metal drivel" and "The only redeeming quality to this record is the intrusive fretless bass sound that kind of sounds like Les Claypool's noodling.

[37] All tracks are written by Chad Gray, Ryan Martinie, Greg Tribbett and Matthew McDonough.