Sex Spa revisits one of the dearest old stag cliches: the dirty doctor who tends to his frustrated clients with “invasive” procedures. The great Keith Erickson, perhaps the only truly noteworthy character actor to arise out of early West Coast porn, tells his new patient that her weight concerns can be easily addressed by his simple diet, exercise and sex regimes.
| Actor | Role |
|---|---|
 Suzanne FieldsNurse | Nurse |
 Ric LutzeMr. Johnson | Mr. Johnson |
 Andy BellamyMiss Stuart (uncredited) | Miss Stuart (uncredited) |
 Nora WieternikMarsha (uncredited) | Marsha (uncredited) |
 Keith EricksonDr. Van Hooperschmidt (uncredited) | Dr. Van Hooperschmidt (uncredited) |