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”).

Corcept Therapeutics (NASDAQ:CORT) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Corcept Therapeutics engages in the discovery, development, and commercialization of drugs for the treatment of severe metabolic and psychiatric disorders. In Portfolio Grader’s specific subcategories of Equity and Cash Flow, CORT also gets F’s. To get an in-depth look at CORT, get Portfolio Grader’s complete analysis of CORT stock.

VIVUS Inc. (NASDAQ:VVUS) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. VIVUS is a biopharmaceutical company engaged in the development and commercialization of therapeutic products for large underserved markets. The stock also gets an F in Equity. As of March 28, 2013, 23.9% of outstanding VIVUS Inc. shares were held short. For a full analysis of VVUS stock, visit Portfolio Grader.

Slipping from C to a D rating, Cempra Holdings LLC (NASDAQ:CEMP) takes a hit this week. Cempra, Inc. manufactures and markets pharmaceutical products. It is a clinical-stage pharmaceutical company, which focuses on developing antibiotics to meet critical unmet medical needs in the treatment of bacterial infectious diseases, particularly respiratory tract infections and skin and skin st… The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of CEMP stock.

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.