UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of the earliest event reported): May 28, 2014

Valeant Pharmaceuticals International, Inc.

(Exact name of registrant as specified in its charter)

2150 St Elzéar Blvd. West

Laval, Quebec

Canada, H7L 4A8

(Address of principal executive offices) (Zip Code)

(Registrant’s telephone number, including area code): (514) 744-6792

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On May 28, 2014, Valeant Pharmaceuticals International, Inc. (“Valeant”) issued a press release announcing that it has sent a letter to the Chairman and Chief Executive Officer of Allergan, Inc. (“Allergan”) relating to an increase in Valeant’s merger proposal for Allergan. A copy of the press release, including the full text of the letter, is attached hereto as Exhibit 99.1. The foregoing description is qualified in its entirety by reference to the text of such press release.

A list of additional persons who may be participants in any solicitation of proxies in respect of any Valeant proposal of a business combination with Allergan is attached hereto as Exhibit 99.2.

ADDITIONAL INFORMATION

This communication does not constitute an offer to buy or solicitation of an offer to sell any securities. This communication relates to a proposal which Valeant has made for a business combination transaction with Allergan. In furtherance of this proposal and subject to future developments, Valeant and Pershing Square Capital Management, L.P. (“Pershing Square”) (and, if a negotiated transaction is agreed, Allergan) may file one or more registration statements, proxy statements or other documents with the SEC. This communication is not a substitute for any proxy statement, registration statement, prospectus or other document Valeant, Pershing Square and/or Allergan may file with the SEC in connection with the proposed transaction. INVESTORS AND SECURITY HOLDERS OF VALEANT AND ALLERGAN ARE URGED TO READ THE PROXY STATEMENT(s), REGISTRATION STATEMENT, PROSPECTUS AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE AS THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION. Any definitive proxy statement(s) (if and when available) will be mailed to stockholders of Allergan and/or Valeant, as applicable. Investors and security holders will be able to obtain free copies of these documents (if and when available) and other documents filed with the SEC by Valeant and/or Pershing Square through the web site maintained by the SEC at http://www.sec.gov.

Information regarding the names and interests in Allergan and Valeant of Valeant and persons related to Valeant who may be deemed participants in any solicitation of Allergan or Valeant shareholders in respect of a Valeant proposal for a business combination with Allergan is available in the additional definitive proxy soliciting materials in respect of Allergan filed with the SEC by Valeant on April 21, 2014 and as Exhibit 99.2 hereto. Information regarding the names and interests in Allergan and Valeant of Pershing Square and persons related to Pershing Square who may be deemed participants in any solicitation of Allergan or Valeant shareholders in respect of a Valeant proposal for a business combination with Allergan is available in additional definitive proxy soliciting material in respect of Allergan filed with the SEC by Pershing Square. The additional definitive proxy soliciting material referred to in this paragraph can be obtained free of charge from the sources indicated above.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EXHIBIT INDEX