Formulas Fatal to the Flesh is the fifth full-length studio album by death metal band Morbid Angel. The Satanic themed lyrics of previous albums had been replaced with lyrics about the Old Ones, which would become the primary source of Morbid Angel's lyrical content from this point on. This is the first album to feature singer/bassist Steve Tucker, replacing David Vincent, and has some lyrical content written in Sumerian.
The title refers to the biblical symbol of the Antichrist. The letter "F" is the 6th letter of the alphabet; therefore, it could be read as "6ormulas 6atal to the 6lesh" or 666 for short, code for the number of the Beast.
The tunings for this record as on Covenant and Domination remained E♭ on six string guitar songs, and B♭ on seven stringed guitar songs.
"Invocation of the Continual One" is made of unused music the band had composed in its early days in 1984, which they put together and re-recorded for this album.