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”).

Supernus Pharmaceuticals Inc.’s (NASDAQ:SUPN) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). In Portfolio Grader’s specific subcategories of Earnings Momentum, Equity, Cash Flow, and Sales Growth, SUPN also gets F’s. For a full analysis of SUPN stock, visit Portfolio Grader.

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. The stock also gets an F in Equity. As of July 25, 2013, 29.3% of outstanding VIVUS Inc. shares were held short. To get an in-depth look at VVUS, get Portfolio Grader’s complete analysis of VVUS stock.

The rating of Cempra Inc. (NASDAQ:CEMP) slips from a C to a D. Cempra manufactures and markets pharmaceutical products. The stock gets F’s in Equity and Cash Flow. For a full analysis of CEMP stock, visit Portfolio Grader.

Corcept Therapeutics (NASDAQ:CORT) is having a tough week. The company’s rating falls from a D to an F. 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 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.