Apply topically to hair and scalp as 1% lotion (cream rinse) or apply topically to skin as 5% cream.

To study effect of permethrin on sodium channel currents antennal lobe neurons of honeybees were used. Membrane currents were measured in the whole-cell configuration using a patch-clamp amplifier. Patch-clamp pipettes were pulled from borosilicate glass capillaries on a vertical pipette puller and then sylgard-coated to minimize pipette capacitance. The resistance of the recording electrode filled with intracellular solution ranged between 3 and 5 MΩ in standard extracellular solution. The liquid junction potential (<3 mV) was not corrected. Microelectrode offset potential was nulled before seal formation. After gigaseal formation and before membrane patch rupture, the resting holding potential was established at −80 mV and the residual microelectrode capacitance was nulled with a fast analog compensation circuit available on the amplifier. In the whole cell configuration, capacitance and series resistance were maximally compensated for. Passive leak currents and residual linear capacitative currents were subtracted using a P/4 protocol. Current-voltage relationships were generated by step depolarizations to test potentials from −80 to +70 mV (10 mV increment) from −80 mV. To assess pyrethroid effects, a single stimulation protocol consisted of a 3 ms depolarization from a holding potential of −80 mV to −10 mV. Trains of repetitive depolarizations at 13 Hz were also used and consisted of ten short stimulations (3 ms to −10 mV) with an interpulse duration (time lapse between the initiation of two successive pulses) of 78 ms. Permethrin was applied at a concentration of 10 uM.