The ratings of three Pharmaceutical stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

VIVUS Inc.’s (NASDAQ:VVUS) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. VIVUS is a biopharmaceutical company engaged in the development and commercialization of therapeutic products for large underserved markets. In Portfolio Grader’s specific subcategory of Equity, VVUS also gets an F. The stock price has fallen 12.4% over the past month, worse than the 1.3% decrease the Nasdaq has seen over the same period of time. As of June 28, 2013, 28.7% of outstanding VIVUS Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of VVUS stock.

This week, Cempra Inc. (NASDAQ:CEMP) drops from a C to a D rating. Cempra manufactures and markets pharmaceutical products. The stock gets F’s in Equity and Cash Flow. To get an in-depth look at CEMP, get Portfolio Grader’s complete analysis of CEMP stock.

Corcept Therapeutics (NASDAQ:CORT) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). Corcept Therapeutics engages in the discovery, development, and commercialization of drugs for the treatment of severe metabolic and psychiatric disorders. The stock gets F’s in Equity and Cash Flow. For a full analysis of CORT stock, visit Portfolio Grader.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.