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): May 16, 2011

Marshall Edwards, Inc.

(Exact name of registrant as specified in its charter)

11975 El Camino Real, Suite 101, San Diego, California 92130

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (858) 792-6300

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 (see General Instruction A.2. below):

Entry into Amended and Restated Securities Purchase Agreement

On May 16, 2011, Marshall Edwards, Inc. (the “Company”) entered into an Amended and Restated Securities Purchase Agreement (the “Amended Purchase Agreement”) with certain accredited investors (the “Purchasers”) which amends and restates in its entirety the Securities Purchase Agreement (the “Original Purchase Agreement”), dated May 2, 2011, between the Company and the Purchasers. As described more fully below, the Amended Purchase Agreement eliminates the series C warrants provided for in the Original Purchase Agreement and provides for the issuance of additional shares (the “Adjustment Shares”) of the Company’s common stock, par value $0.00000002 per share (the “Common Stock”), and cash payments to the Purchasers to the extent the trading price of the Common Stock is below certain levels on the Adjustment Dates (as defined below).

Pursuant to the Amended Purchase Agreement, the Company has agreed to issue and sell to the Purchasers: (i) 835,217 shares (the “Common Shares”) of Common Stock, at a purchase price of $1.333 per share; (ii) series A warrants (the “Series A Warrants”) which will initially represent the right to purchase up to 626,413 shares of Common Stock; and (iii) series B warrants (the “Series B Warrants”, and collectively with the Series A Warrants, the “Warrants”) which will initially represent the right to purchase up to 2,165,534 shares of Common Stock. In addition, subject to the receipt of Stockholder Approval (as defined below), the Company has agreed to issue to the Purchasers Adjustment Shares to the extent the applicable price of the Common Stock is below $1.333 per share, but greater than or equal to $0.75 per share, on certain dates (“Adjustment Dates”) during the one year period ending on the first anniversary of the date of the closing of the offering, including as a result of a subsequent offering by the Company of its securities at a price below the purchase price of the Common Shares. The number of Adjustment Shares issuable will initially be limited to 649,242, subject to proportionate increases to the extent the Series B Warrants have been exercised prior to the applicable Adjustment Date, up to a maximum of 2,332,583 shares. If the applicable price based on the trading price of the Company’s common stock is below $0.75 per share on any Adjustment Date, the Company will, in addition to issuing the applicable number of Adjustment Shares, refund to the Purchasers an amount in cash per share of Common Stock purchased by the Purchasers in the transaction based on the difference between $0.75 and the price of the Common Stock on such Adjustment Date.

Upon the closing of the offering, the Company has also agreed to issue to Roth Capital Partners, as placement agent, warrants for the purchase of an amount of Common Stock equal to 7% of the Common Shares, which warrants will be exercisable on the same terms, including as to the increase in the number of shares of Common Stock issuable upon exercise, as the Series A Warrants, as well as to pay a cash fee equal to 7% of the gross proceeds of the offering.

The Common Shares, the Warrants and the Adjustment Shares are being offered and sold in a private placement transaction exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”) in reliance upon Section 4(2) under the Securities Act and Regulation D promulgated thereunder. Each of the investors represented to the Company that it is an “accredited investor” as defined in Rule 501 of Regulation D.

Also on May 16, 2011, the Company entered into an Amended and Restated Registration Rights Agreement (“Amended RRA”) with the Purchasers pursuant to which the Company has agreed to file, within 30 days of the closing of the offering (the “Filing Deadline”), a registration statement (“Registration Statement”) with the Securities and Exchange Commission registering the Common Shares and the Common Stock issuable upon exercise of the Warrants for resale. In the event the Company (i) does not file the Registration Statement on or before the Filing Deadline, (ii) the Registration Statement is

not declared effective on or before the associated effectiveness deadline, or (iii) the Company fails to maintain the effectiveness of the Registration Statement, other than during certain permitted grace periods, the Company will be required to pay liquidated damages on a monthly basis in an amount equal to 2% of the aggregate purchase price paid by the Purchasers for any unregistered securities then held by the Purchasers. To the extent the Company is not able to register all of the Common Shares and shares of Common Stock issuable upon exercise of the Warrants on the initial registration statement, the Company must file additional registration statements until all of such securities may be sold either pursuant to an effective registration statement or in accordance with Rule 144 of the Securities Act without restrictions or limitations, including the requirement to be in compliance with Rule 144(c)(1).

Conditions to Closing; Stockholder Approval

Consummation of the transactions contemplated by the Amended Purchase Agreement (collectively, the “Transaction”) is subject to certain conditions, including the execution and delivery of the Amended and Restated Voting Agreement (“Amended Voting Agreement”), dated May 16, 2011, between the Company and Novogen Limited (“Novogen”), in its capacity as majority stockholder of the Company. On May 16, 2011, immediately after the execution of the Amended Purchase Agreement, pursuant to the terms of the Amended Voting Agreement, Novogen executed a written consent approving the Transaction, which approval will become effective 20 days after the Company has mailed a definitive information statement to its stockholders (the “Stockholder Approval”). Upon issuance of the Common Shares, Novogen’s ownership of the Company’s outstanding Common Stock will be reduced from approximately 65.1% to approximately 59.0%, subject to further reduction in the event any of the Warrants are exercised or any Adjustment Shares are issued. Novogen also owns 1,000 shares of the Company’s series A convertible preferred stock, par value $0.01, each share of which is convertible at any time and from time to time and without the payment of additional consideration into 4,827 shares of Common Stock. In addition, if a Phase II clinical trial involving the Company’s isoflavone technology has achieved a statistically significant result (p=0.05 or less) or a first patient is enrolled in a Phase III clinical trial involving the Company’s isoflavone technology, then any share of the series A convertible preferred stock not already converted may thereafter be converted into 9,654 shares of Common Stock.

Terms of Warrants

The Series A Warrants will be exercisable any time on or after the six month anniversary of the closing of the offering at an initial exercise price of $1.57 per share, subject to adjustment as provided in the Series A Warrants. However, unless and until such time as the Company obtains the Stockholder Approval, the exercise price for the Series A Warrants shall not be less than $1.57 per share. The number of shares of Common Stock issuable upon exercise of the Series A Warrants will be increased by an amount equal to 75% of the number of shares of Common Stock issued upon each exercise of the Series B Warrants. The Series A Warrants will expire on the fifth anniversary of the date on which the Series A Warrants first become exercisable.

The Series B Warrants will be exercisable by the holders at any time on or after the first date on which all of the following conditions are satisfied (or, in the case of clause (ii) or (iii), waived by the holder): (i) the Stockholder Approval has been obtained, (ii) all of the shares of Common Stock issuable upon exercise of the Series B Warrants are able to be resold without restriction or limitation pursuant to an effective registration statement and (iii) all of the Common Shares, the shares of Common Stock issuable upon exercise of the Warrants and the Adjustment Shares are able to be resold without restriction or limitation pursuant to an effective registration statement or Rule 144 under the Securities Act. The initial exercise price per share of the Series B Warrants is equal to the lower of (i) $1.333, and (ii) 85% of the arithmetic average of the lowest eight weighted average prices of the Common Stock during the 20 consecutive trading day period (a) in the case of a voluntary exercise by the holders, ending on the trading day immediately preceding the

date of delivery of a notice of exercise, and (b) in the case of the required exercise discussed below, immediately following the fifth trading day following the date of delivery of a notice of such required exercise. The Company may require the holders to exercise their Series B Warrants in the event of satisfaction of the conditions set forth in the first sentence of this paragraph, as well as certain other equity conditions, including certain minimum trading volume requirements. The Series B Warrants will expire on the first anniversary of the closing of the offering.

The Series A Warrants and the Series B Warrants are subject to certain anti-dilution adjustments, including, upon the sale or deemed sale by the Company after the date of the Amended Purchase Agreement of any shares of Common Stock at a price per share below the exercise price of the Series A Warrants or the Series B Warrants, the reduction of the exercise price of the applicable series of warrants to an amount equal to such lower price. In addition, if at any time after the date of the Amended Purchase Agreement the Company subdivides or combines any of its outstanding shares of Common Stock into a greater or lesser number of shares, the exercise price and the number of shares of Common Stock issuable upon exercise of each series of Warrants will be proportionately increased or decreased, as applicable. Each series of Warrants also contains a provision which limits each holder’s beneficial ownership to a maximum of 9.99% of the shares of Common Stock outstanding immediately after giving effect to any exercise of such Warrants.

Conditions to Issuance of Adjustment Shares

The initial Adjustment Date for the issuance of Adjustment Shares will be the date that is the 26th trading day after the earliest of (1) the date that all Registrable Securities (as defined in the Amended RRA) and the Adjustment Shares have been registered pursuant to an effective registration statement that is available for the resale of all such Registrable Securities and Adjustment Shares, (2) the date that the holder can sell all of the Adjustment Shares pursuant to Rule 144 without any restrictions or limitations and (3) the six-month anniversary of the date of the closing of the offering. However, in the event the Stockholder Approval has not been obtained by the earliest of such dates, in lieu of delivering the Adjustment Shares, the Company will pay to each holder an amount in cash equal to the number of Adjustment Shares otherwise deliverable upon such date multiplied by the weighted average price of the Common Stock on such Adjustment Date. If, following the initial Adjustment Date, the Company fails to maintain the effectiveness of any such registration statement or the public information required by Rule 144 during a period of 60 days after the prior Adjustment Date, there may be either one or two additional Adjustment Dates, the last of which would be the one year anniversary of the closing of the offering. In addition, Adjustment Shares will be issuable, subject to limitations on the number of Adjustment Shares described above, upon the occurrence of an Allowed Subsequent Placement (as defined below).

Lock-up Agreements; Restrictions on Additional Offerings

In connection with the Amended Purchase Agreement, Novogen and each of the officers and directors of the Company have entered into amended and restated lock-up agreements (the “Amended Lock-up Agreements”) pursuant to which such person has agreed not to sell, transfer or otherwise dispose of any shares of Common Stock or securities convertible or exchangeable for shares of Common Stock owned by such person until, in the case of Novogen, December 24, 2011, and, in the case of the officers and directors of the Company, until the earlier of (i) 90 days after the date on which all of the securities required to be registered pursuant to the Amended RRA, as well as the Adjustment Shares, have either been registered pursuant to an effective registration statement or can be sold pursuant to Rule 144 without any restrictions or limitations, and (ii) the date that is thirteen months after the date of the closing of the offering.

The Company has also agreed generally not to make any further offers or sales of any of its equity securities until the earlier of (i) 90 days after the date on which all of the securities required to be registered pursuant to the Amended RRA have been so registered and (ii) the date that is thirteen months after the date of the closing of the offering. However, certain offers and sales are excluded from the foregoing restriction, including the offer and sale of a specified amount of additional Common Stock and warrants to purchase Common Stock (an “Allowed Subsequent Placement”) during the period beginning on the later of (a) 120 days after the closing of the offering, and (b) the earlier of the date on which the Common Shares have been registered pursuant to an effective registration statement or can be sold pursuant to Rule 144 without any restrictions or limitations.

The foregoing description of the Amended Purchase Agreement, the Amended RRA, the Amended Voting Agreement, the Amended Lock-up Agreements and the Warrants does not purport to be complete and is qualified in its entirety by reference to the full text of those documents or the forms thereof that are included as Exhibits 10.1, 10.2, 10.3, 10.4, 10.5 and 10.6 hereto, respectively, and incorporated herein by reference.

This description does not constitute an offer to sell or the solicitation of an offer to buy any securities. The Common Shares, the Warrants, the shares of Common Stock issuable upon exercise of the Warrants and the Adjustment Shares have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements under the Securities Act or applicable state securities laws.

The disclosures set forth under Item 1.01 of this Current Report on Form 8-K are incorporated herein by reference.

The disclosures set forth under Item 1.01 of this Current Report on Form 8-K are incorporated herein by reference.

(d) Exhibits

Signature

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.

Dated: May 16, 2011

Exhibit Index