CDXC ChromaDex Corporation

EXPLANATORY STATEMENT .

This Amendment No. 4 to Schedule 13D (“ Amendment No.  4 ”) relates to shares of Common Stock of the Issuer (“ Shares ”) and is being filed on behalf of the Reporting Persons. This Amendment No. 4 amends and supplements the Amendment No. 3 to Schedule 13D previously filed with the Securities and Exchange Commission (the “ SEC ”) on November 7, 2017 (“ Amendment No.  3 ”), the Amendment No. 2 to Schedule 13D previously filed with the SEC on May 26, 2017 (“ Amendment No.  2 ”), the Amendment No. 1 to Schedule 13D previously filed with the SEC on May 11, 2017 (“ Amendment No.  1 ”), and the initial Schedule 13D previously filed with the SEC on May 8, 2017 (the “ Initial Schedule 13D ”, together with Amendment No. 1, Amendment No. 2, Amendment No. 3, and this Amendment No. 4, the “ Schedule 13D ”). This Amendment No. 4 is being amended to reflect certain changes to the aggregate amount of Shares beneficially owned by the Reporting Persons.

ITEM 4. PURPOSE OF TRANSACTION.

November 2017 Securities Purchase Agreement

On November 3, 2017, Pioneer Step Holdings Limited (“ Pioneer Step ”) and certain other purchasers named therein (each a “ November 2017 Purchaser ” and together, the “ November 2017 Purchasers ”) entered into a Securities Purchase Agreement with the Issuer (the “ November 2017 Purchase Agreement ”). Pursuant to the November 2017 Purchase Agreement, the Issuer agreed to issue and sell to the November 2017 Purchasers an aggregate of approximately $23 million of Common Stock (5,609,755 Shares) at a purchase price of $4.10 per share (the “ November 2017 Transaction ”). Pioneer Step, in its capacity as a November 2017 Purchaser, has agreed to purchase 487,805 Shares in the November 2017 Transaction. The November 2017 Transaction closed on November 17, 2017, at which closing the Issuer issued 487,805 Shares to Pioneer Step and 5,121,950 Shares to the other November 2017 Purchasers.

April 2017 Securities Purchase Agreement

On April 26, 2017, Pioneer Step Holdings Limited (“ Pioneer Step ”) and Champion River Ventures Limited (“ Champion River ”, each an “ April 2017 Purchaser ” and together, the “ April 2017 Purchasers ”) entered into a Securities Purchase Agreement with the Issuer (the “ April 2017 Purchase Agreement ”). Pursuant to the April 2017 Purchase Agreement, the Issuer agreed to sell and issue to the April 2017 Purchasers an aggregate of up to $25 million of its Common Stock at a purchase price of $2.60 per share in three tranches of approximately $3.5 million, $16.4 million and $5.1 million, respectively. The first tranche (the “ First Tranche ”) closed on April 27, 2017, at which closing the Issuer issued 538,462 Shares to Pioneer Step and 807,692 Shares to the other April 2017 Purchaser. Pursuant to the First Amendment to Securities Purchase Agreement, dated May 24, 2017 (the “ First Amendment ”), by and among the Issuer and the April 2017 Purchasers, the second tranche (the “ Second Tranche ”) closed on May 24, 2017, at which closing the Issuer issued 2,521,526 Shares to Pioneer Step and 3,782,288 Shares to the other April 2017 Purchaser. Pursuant to the First Amendment, following approval by the Issuer’s stockholders, the third tranche (the “ Third Tranche ”) closed on August 18, 2017, at which closing the Issuer issued 786,167 Shares to Pioneer Step and 1,179,250 Shares to the other April 2017 Purchaser.

Upon completion of the Second Tranche, the April 2017 Purchase Agreement required that the Issuer’s Board of Directors (the “ Board ”) increase the number of authorized directors so as to create two vacant seats on the Board, which vacancies were to be filled on a date following the Issuer’s 2017 Annual Meeting of Stockholders by one designee selected by each of the April 2017 Purchasers (the “ Purchaser Designees ”). As such, Pioneer Step exercised its right to designate for appointment an individual to fill one of the two new vacancies on the Issuer’s Board. Thereafter, on August 18, 2017, in connection with the closing of the Third Tranche, Wing Tak Wendy Yu was designated by the Reporting Persons and appointed by the Issuer as a director.

In addition, from and after the date of the April 2017 Purchase Agreement, upon prior written request thereof by any April 2017 Purchaser, the Issuer shall use reasonable efforts to enter into one or more voting agreements with one or more of the April 2017 Purchasers and such other substantial holders of Common Stock as reasonably requested by such April 2017 Purchaser(s) and agreed to by the Issuer in respect of the election of the Purchaser Designees.

November 2017 Registration Rights Agreement

Simultaneously with the execution of the November 2017 Purchase Agreement, the Issuer, Pioneer Step and the other November 2017 Purchasers entered into a Registration Rights Agreement, dated November 3, 2017 (the “ November 2017 Registration Rights Agreement ”) with respect to the Shares acquired under the November 2017 Purchase Agreement. The November 2017 Registration Rights Agreement grants Pioneer Step and the other November 2017 Purchasers customary shelf and piggyback registration rights.

April 2017 Registration Rights Agreement

At the closing of the First Tranche, the April 2017 Purchase Agreement required that the Issuer and the April 2017 Purchasers promptly enter into a Registration Rights Agreement in form and substance reasonably acceptable to the April 2017 Purchasers (the “ April 2017 Registration Rights Agreement ”) with respect to the Shares acquired under the April 2017 Purchase Agreement. The Issuer and the April 2017 Purchasers entered into the April 2017 Registration Rights Agreement on April 29, 2017. The April 2017 Registration Rights Agreement grants the April 2017 Purchasers customary shelf and piggyback registration rights.

The foregoing descriptions of the November 2017 Purchase Agreement, the April 2017 Purchase Agreement, the November 2017 Registration Rights Agreement, the April 2017 Registration Rights Agreement, and the First Amendment are not complete and are qualified in their entirety by reference to the full text of the November 2017 Purchase Agreement, the April 2017 Purchase Agreement, the November 2017 Registration Rights Agreement, the April 2017 Registration Rights Agreement, and the First Amendment, which are incorporated by reference into this Schedule 13D pursuant to Exhibits 99.2, 99.3, 99.4, 99.5, and 99.6 of Item 7 hereof.

Pioneer Step acquired the Shares pursuant to the April 2017 Purchase Agreement and the November 2017 Purchase Agreement as investments in its ordinary course of business.

In connection with the foregoing, and as may be appropriate from time to time, each of the Reporting Persons may consider the feasibility and advisability of various alternative courses of action with respect to its investment in the Issuer, including, without limitation: (a) the acquisition or disposition by the Reporting Persons of Shares, including through derivative transactions which may include security-based swaps and short sales; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) changes in the present board of directors or management of the Issuer; (e) a material change in the present capitalization or dividend policy of the Issuer; (f) other material changes in the Issuer’s business or corporate structure; (g) changes in the Issuer’s articles of incorporation or bylaws or other actions that may impede the acquisition of control of the Issuer by any person; (h) causing any class of the Issuer’s securities to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) causing a class of equity securities of the Issuer to become eligible for termination of registration pursuant to Section 12 of the Exchange Act; or (j) any action similar to those enumerated above.

Except as described in Item 6 and this Item 4 and any plans or proposals that may from time to time be discussed or considered by the directors of the Issuer, including the Purchaser Designee, in her fiduciary capacity as a director of the Issuer, the Reporting Persons do not currently have any plans or proposals that relate to or would result in any of the actions specified in clause (a) through (j) of this paragraph.

The Reporting Persons reserve the right, based on all relevant factors and subject to applicable law or other restrictions, at any time and from time to time, to acquire additional Shares, dispose of some or all of the Shares, in each case in open market or private transactions, block sales or otherwise, and review or reconsider their position, change their purpose, take other actions (including actions that could involve one or more of the types of transactions or have one or more of the results described in clauses (a) through (j) of the foregoing paragraph of this Item 4) or formulate and implement plans or proposals with respect to any of the foregoing. Except as set forth in this Schedule 13D, no contract, arrangement, relationship or understanding (either oral or written) exists among the Reporting Persons as to the acquisition, disposition, voting or holding of Shares.

The Reporting Persons intend to review their investment in the Issuer from time to time on the basis of various factors, including the Issuer’s business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer’s stock in particular, as well as other developments.

ITEM 5. INTEREST IN SECURITIES OF THE ISSUER.

(a) and (b) As of November 21, 2017, Pioneer Step beneficially owned and had sole voting and dispositive power with respect to 4,333,960 Shares, representing approximately 8.1% of the 53,797,053 outstanding Shares as of the date of this Schedule 13D, based on 48,187,298 Shares reported by the Issuer to be issued and outstanding as of November 8, 2017, as set forth in the Issuer’s quarterly report on Form 10-Q, for the quarter ended September 30, 2017, as filed with the Securities and Exchange Commission on November 9, 2017, plus 5,609,755 Shares issued in the November 2017 Transaction to Pioneer Step and the other November 2017 Purchasers pursuant to the November 2017 Purchase Agreement, described in Item 4 of this Schedule 13D.

As of November 21, 2017, Solina Chau, by virtue of being the sole shareholder of Pioneer Step, may be deemed to beneficially own and have sole voting and dispositive power with respect to the Shares beneficially owned by Pioneer Step.

The share ownership reported by Pioneer Step on this Schedule 13D does not include any Shares owned by other November 2017 Purchasers, and each of Pioneer Step and the other Reporting Person on this Schedule 13D disclaims beneficial ownership of any Shares owned by any other person.

(c) Information with respect to all transactions in the Shares beneficially owned by the Reporting Persons that were effected during the past sixty days is set forth in Item 4 and incorporated herein by reference.

(d) Not applicable.

(e) Not applicable.

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief, the undersigned certifies that the information set forth in this Statement is true, complete and correct.

Dated: November 21, 2017

EXHIBIT INDEX