This week, the overall grades of three pharmaceutical stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

VIVUS, Inc.’s (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. VVUS also rates an F in Portfolio Grader’s specific subcategory of Equity. As of Dec. 27, 2013, 30.9% of outstanding VIVUS, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of VVUS stock.

Cempra, Inc. (CEMP) is having a tough week. The company’s rating falls from a C to a D. 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 Incorporated.’s (CORT) rating falls this week to an F (“strong sell”), down from last week’s 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.