A quick check on Google turned up the following information:
http://glswrk-auction.com/mc15.htm
"A recent addition to my “medicine chest†is an amber, rectangular bottle, 8 1/4 inches tall, embossed G.F.P. / For / Women // Gerstle Medicine Co. // Chattanooga, Tenn. G.F.P. stands for Gerstle's Female Panacea. Leopold Gerstle started small in Union Tenn., in 1871. By 1889 the town was called Bluff City when Gerstle and the town council had a “falling out†over increases in tax and water rates, and Gerstle moved his growing business to Chattanooga. An 1895 ad lists L. Gerstle & Co., Manufacturing Druggists, Office and Laboratory on Electric Street Halloway, Highland Park. St. Joseph's Sarsaparilla and St. Joseph's Liver Regulator were advertised as well as G.E.P. The Sarsaparilla came in an 8 3/4 inch tall amber rectangular bottle embossed S.J.S. / For The / Blood // Gerstle Medicine Co. // Chattanooga, Tenn. St. Joseph's Family Medicines, L. Gerstle & Co. Continued to be listed in the Chattanooga City Directories through 1920, and the company continues to the present as the St. Joseph's Medicine Co."
Kovel's (http://www.kovels.com/) list the 1996 price as $45