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 Earliest Event Reported): January 22, 2015

SALIX PHARMACEUTICALS, LTD.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (919) 862-1000

Not Applicable

(Former name or former address, if changed since last report)

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:

Item 4.02. Non-Reliance on Previously Issued Financial Statements or a Related Audit Report or Completed Interim Review.

On January 22, 2015, the Audit Committee of the Board of Directors (the “Audit Committee”) of Salix Pharmaceuticals, Ltd. (the “Company”), after discussion with management and the Company’s independent registered public accounting firm, Ernst & Young LLP (“EY”), concluded that the Company’s previously issued audited consolidated financial statements for the year ended December 31, 2013 and the previously issued unaudited consolidated financial statements for the fiscal quarters ended March 31, June 30, and September 30, 2014, and the disclosures and related communications for each of those periods, require correction of certain errors and should no longer be relied upon. Management’s report on internal controls over financial reporting for the year ended December 31, 2013 should no longer be relied upon. Additionally, EY’s opinion on the consolidated financial statements for the year ended December 31, 2013, as well as EY’s opinion on the effectiveness of the Company’s internal controls over financial reporting as of December 31, 2013 should no longer be relied upon.

The impact of these errors, which are primarily associated with the timing for recognition of certain revenue, revenue-reducing returns and discounts, and expenses, on previously reported net income or loss after income taxes for each of these periods is estimated to be as follows:

The Company anticipates that it will file its Annual Report on Form 10-K for the fiscal year ended December 31, 2014 (the “2014 10-K”) on a timely basis on or before March 2, 2015. Immediately prior to filing the 2014 10-K, the Company will restate the financial results contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2013 and the previously unaudited financial statements and other financial information contained in the Company’s Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, June 30, and September 30, 2014, and the disclosures and related communications for these periods (collectively the “Prior Financial Information”). The Audit Committee and the Company presently do not expect to identify any material adjustments in the restated financial statements other than those discussed below.

As previously disclosed, the Audit Committee has been conducting a review of prior public disclosures of inventory amounts in the distribution channel and related issues in press releases, on analyst calls, and in the Company’s various SEC filings. Outside counsel, reporting to the Audit Committee, has engaged BDO Consulting, a division of BDO USA, LLP (“BDO”), to assist in the review of accounting and financial reporting issues associated with sales to wholesalers and other wholesaler-related transactions. The Audit Committee’s review also prompted the Company to reevaluate its classification of certain expenses, which has resulted in the estimated changes identified below to certain classifications.

The following are errors that the Audit Committee and the Company recently identified that will be corrected through the restatements.

The following are immaterial errors that were previously identified which now will be corrected as part of the restatement of the errors above:

The Company is working with the Audit Committee and the Audit Committee’s advisors to determine the final adjustments required to be made to the Prior Financial Information as expeditiously as possible. Based on the information presently available, the Company expects the following restated financial results:

Summary of Expected Adjustments for the Restatement of the Consolidated Financial Statements of Salix Pharmaceuticals, Ltd.

In light of the Audit Committee’s review, the Company and the Audit Committee are reevaluating the Company’s internal control over financial reporting and its disclosure controls and procedures. Management, in consultation with the Audit Committee, also has determined that material weaknesses existed in the Company’s internal control over financial reporting and that disclosure controls and procedures were ineffective at December 31, 2013 and through December 31, 2014. In consultation with the Audit Committee and its counsel, the Company intends to enhance its procedures and controls based on information identified during the Audit Committee’s review and the restatement process.

The Audit Committee and the Company’s management have discussed the matters disclosed in this Item 4.02 with Ernst & Young LLP.

Item 7.01. Regulation FD Disclosure.

On January 28, 2015, the Company issued a press release regarding the matters discussed in Item 4.02 above. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

The information in this Item 7.01, including the related press release, is being furnished pursuant to Item 7.01 of Form 8-K and General Instruction B.2 thereunder, and shall not be deemed to be “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section. This information shall not be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, regardless of any general incorporation language in such filing. This information will not be deemed an admission as to the materiality of such information that is being disclosed solely pursuant to Regulation FD.

Item 9.01. Financial Statements and Exhibits.

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