The assessment of zinc levels after oral administration of 100 mg of zinc gluconate was performed over a 72-hour period in 3 sectors: plasma, blister fluid and epidermis. The results show that zinc taken orally reaches the epidermis after 72 h and indicate the existence of an intermediary compartment between plasma and epidermis, represented by blister fluid, in which zinc concentration is 243.9 +/- 32.2 micrograms/l, that is, the ratio blister fluid/plasma = 0.33.