Swollen and painful extremities have been treated with herbal baths in attempts to alleviate thesymptoms. A popular herbal bath used in China, contains a component called ‘bone-penetratingherb’ which is believed to facilitate the penetration of herbal substances across the skin to theswollen site, so that pain and swelling will be improved. A search from the Chinese pharmacopediarevealed that 22 different herbs have been traditionally used as ‘bone-penetrating herb’. Five ofthese herbs were available in market and were chosen for experimental studies. Standarddiffusion experiments were done to identify the most effective herb among the five, in thepenetration facilitation. Glechoma longituba at a concentration of 20% was found to give the bestresults in the facilitation of Bromophenol blue diffusion across artificial and biologicalmembranes. When compared with one commonly used diffusion facilitator, viz. azone, azonewas found to be more effective than glechoma longituba. The encouraging observations supportfuture studies on the basic science behind the use of herbal components as topical agents to treatpain and swelling.