This study evaluated the effect of locally applied heat on the transdermal
delivery of testosterone. Six healthy adult volunteers were tested three ti
mes while receiving a 5 mg androgen patch, the same patch with a heat-gener
ating patch, and no patch at oil over 12 hours. Statistically significant d
ifferences in mean maximum serum testosterone concentration values were see
n. Heat plus patch resulted in a mean maximum serum testosterone concentrat
ion of 939 ng/dl versus 635 ng/dl (patch only) and 425 ng/dl (no patch). (H
eat + patch vs, no patch: p < 0.001; heat + patch vs. patch :p < 0. 001; pa
tch vs. no patch:p = 0.003.) The area under the curve of plasma testosteron
e concentration versus time values were means of 4114 ng/dl(.)h versus 1985
ng/dl(.)hfor the patch-only group (p 0.001). The use of heat improved abso
rption of transdermal testosterone and decreased time to peak serum testost
erone concentrations, resulting in a statistically significant difference i
n mean maximum serum testosterone concentrations compared with the use of t
he patch without heat.