In the history of suction-assisted lipectomy, ultrasonic liposculpture and body contouring procedures, Klein's formula for the tumescent technique represents an important milestone. Since 1987 the formula has been altered by other clinicians. Although initially created for outpatient surgery without the services of an anesthetist, the technique is nowadays used so frequently that it cannot any longer be considered as a minor office procedure. It is useful to examine the ingredients of the various formula used in order to justify their use. This paper contains five sections. Part one deals with the fluid required by the various authors. Water and electrolytes exchanges in relation to the interstitial compartment are reviewed. Part two considers local anesthetics, their toxicity and the maximum safe dose. Part three considers the controversy on epinephrine. Part four comments on the addition of sodium bicarbonate to the solution. Part five explains why infiltration of chilled solutions is inappropriate. The following regimen is advised as a result of the above studies: lactated Ringer's solution is the fluid of choice; lidocaine: 500 rag/1 as the reference anesthetic. The maximum safe dose recommended for liposuction is 35 mg/kg over 45 rain (PDR recommendations: 7 mg/kg). Epinephrine: 1 rag/1. Prospective studies ought to be done on the topic: Sodium bicarbonate 8.4%: 5 MEq/1 (optional). Higher doses are of no value but are not harmless. The fluids to be infiltrated at room temperature rather than chilled.