Exhibit 7.1 September 29, 1999 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, DC 20549 Gentlemen: We have read Item 4 of Form 8-K dated September 29, 1999 of Human Pheromone Sciences, Inc. and are in agreement with the statements contained in the first and second paragraphs on page 2 therein. Very truly yours, /s/ Ernst & Young LLP San Francisco, California -4-