The ratings of four 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. (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. For Portfolio Grader’s specific subcategory of Equity, VVUS also gets an F. The stock price has dropped 6.1% over the past month, worse than the 1.3% decrease the Nasdaq has seen over the same period of time. As of Aug. 16, 2013, 30.4% of outstanding VIVUS, Inc. shares were held short. For a full analysis of VVUS stock, visit Portfolio Grader.

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. Wall Street appears to agree with the stock downgrade, with share prices dropping 6% over the past month. For more information, get Portfolio Grader’s complete analysis of CEMP stock.

This week, TherapeuticsMD, Inc.’s (AMEX:TXMD) rating worsens to a D from the company’s C rating a week ago. TherapeuticsMD operates as a women’s healthcare product company in the United States. The stock gets F’s in Equity and Cash Flow. To get an in-depth look at TXMD, get Portfolio Grader’s complete analysis of TXMD stock.

Corcept Therapeutics Incorporated. (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. Share prices fell 20% over the past month. For more information, get Portfolio Grader’s complete analysis of CORT 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.