UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

(Amendment No. 2)

x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarter ended: September 30, 2011

OR

¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

For the Transition Period from ___________ to____________

Commission File Number: 000-53166

MUSCLEPHARM CORPORATION

(Exact name of registrant as specified in its charter)

4721 Ironton Street, Building A

Denver, CO 90839

(Address of principal executive offices and zip code)

(303) 396-6100

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by section 13 or 15(d) of the Securities Exchange Act of 1934 during the past 12 months, and (2) has been subject to such filing requirements for the past 90 days. Yes x  No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files. Yes  ¨  No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act:

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes ¨  No x

As of July 6, 2012, there were 1,399,074,207 shares outstanding of the registrant’s common stock.

EXPLANATORY NOTE

The purpose of this Amendment No.2 (the “Amendment”) to MusclePharm Corporation’s (the “Company”) quarterly report on Form 10-Q for the period ended September 30, 2011, originally filed with the U.S. Securities and Exchange Commission on July 2, 2012 (the “Form 10-Q), is solely to furnish Exhibit 101 to the Form 10-Q in accordance with Rule 405 of Regulation S-T.

No other changes have been made in this Amendment to the Form 10-Q. This Amendment speaks as of the original date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date and does not modify or update in any way disclosures made in the original Form 10-Q.

Pursuant to rule 406T of Regulation S–T, the interactive data files on Exhibit 101 attached hereto are deemed not filed or part of a registration statement or prospectus for purposes of Sections 11 or 12 of the Securities Act of 1933, as amended, are deemed not filed for purposes of Section 18 of the Securities Act of 1934, as amended, and otherwise are not subject to liability under those sections.

ITEM 6.  EXHIBITS.

SIGNATURES

In accordance with the requirements of the Exchange Act, the registrant caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.