Exhibit 4.1

DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

As of the date of the Annual Report on Form 10-K of which this exhibit forms a part, the only class of securities of Perspective Therapeutics, Inc. (“we,” “us” and “our”) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is our common stock, $0.001 par value per share.

The following description of our common stock summarizes provisions of our Amended and Restated Certificate of Incorporation (the “Certificate of Incorporation”), our Amended and Restated Bylaws (the “Bylaws”) and the Delaware General Corporation Law (the “DGCL”). For a complete description, refer to our Certificate of Incorporation and our Bylaws, which are incorporated by reference as exhibits to the Annual Report on Form 10-K of which this exhibit is a part, and to the applicable provisions of the DGCL.

General

We are authorized to issue up to 750,000,000 shares of common stock, par value $0.001 per share.

The holders of our common stock have no preemptive or other subscription rights, and there are no conversion rights or redemption or sinking fund provisions with respect to such shares of common stock. All of the outstanding shares of our common stock are, and the shares of our common stock when issued will be, fully paid and nonassessable.

Voting. Holders of our common stock are entitled to one vote per share of common stock on all matters to be voted on by our stockholders, provided, however, that, except as otherwise required by law, holders of common stock are not entitled to vote on any amendment to the Certificate of Incorporation that relates solely to the terms of one or more outstanding series of preferred stock if the holders of such affected series are entitled, either separately or together as a class with the holders of one or more other such series, to vote thereon pursuant to the Certificate of Incorporation. The Bylaws provide that except as otherwise provided by applicable law, the Certificate of Incorporation, or the Bylaws, the presence, in person or by proxy, of the holders of a majority of the voting power of all outstanding shares of stock entitled to vote at the meeting constitutes a quorum.

Dividends. Our Board of Directors (the “Board”), in its sole discretion, may declare and pay dividends on our common stock, payable in cash or other consideration, out of funds legally available, if all dividends due on the preferred stock have been declared and paid. We have not paid any cash dividends on our common stock and do not plan to pay any cash dividends on our common stock for the foreseeable future.

Liquidation, Subdivision, or Combination. In the event of any liquidation, dissolution or winding up of us or upon the distribution of our assets, all assets and funds remaining after payment in full of our debts and liabilities, and after the payment to holders of any then outstanding preferred stock of the full preferential amounts to which they were entitled, would be divided and distributed among holders of the common stock.

Registration Rights

In connection with the Merger Agreement, on January 31, 2023, we entered into a Registration Rights and Lock-Up Agreement with each of the stockholders of Viewpoint (the “Registration Rights Agreement”). Pursuant to the Registration Rights Agreement (i) we agreed to file a resale registration statement for the Registrable Securities (as defined therein) no later than 30 days following the closing of the merger, and to use commercially reasonable efforts to cause it to become effective as promptly as practicable following such filing, (ii) the stockholders have been granted certain piggyback registration rights with respect to registration statements filed subsequent to the closing of the merger, and (iii) the Lock-Up Holders (as defined in therein) agreed, subject to certain customary exceptions, not to sell, transfer, or dispose of any of our common stock until the earlier of (a) six months, or (b) the date on which we complete a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of our stockholders having the right to exchange their shares of common stock for cash, securities, or other property.

Anti-Takeover Provisions

Section 203 of the Delaware General Corporation Law

Pursuant to the Certificate of Incorporation, we elected not to be governed by Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, with certain exceptions.

Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws

Because our stockholders do not have cumulative voting rights, stockholders holding a majority of the shares of common stock outstanding are able to elect all of our directors. The Bylaws provide that directors may be removed by the stockholders with or without cause upon the vote of a majority of the shares then entitled to vote at an election of directors. Furthermore, the authorized number of directors may be changed only by resolution of our Board, and vacancies and newly created directorships on our Board may, except as otherwise required by law or the Certificate of Incorporation, only be filled by a majority vote of the directors then serving on our Board, even though less than a quorum.

The Bylaws also provide that stockholders seeking to present proposals before a meeting of stockholders to nominate candidates for election as directors or any other business to be properly brought at a meeting of stockholders must provide timely advance notice in writing and specify requirements as to the form and content of a stockholder’s notice.

The Certificate of Incorporation provides our Board the authority, without further action by our stockholders, to issue up to 7,000,000 shares of preferred stock in one or more series, with any rights, preferences and privileges as they may designate, including the right to approve an acquisition or other change in control.

The combination of these provisions makes it more difficult for our existing stockholders to replace our Board as well as for another party to obtain control of us by replacing our Board. Since our Board has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management. In addition, the authorization of undesignated preferred stock makes it possible for our Board to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to change control of us.

These provisions are intended to enhance the likelihood of continued stability in the composition of our Board and its policies and to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to reduce our vulnerability to hostile takeovers and to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and may have the effect of delaying changes in our control or management. As a consequence, these provisions may also inhibit fluctuations in the market price of our stock that could result from actual or rumored takeover attempts. We believe that the benefits of these provisions, including increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure our company, outweigh the disadvantages of discouraging takeover proposals, because negotiation of takeover proposals could result in an improvement of their terms.

Choice of Forum

Our Bylaws provide that, unless we consent in writing to the selection of an alternative forum, the sole and exclusive forum for any claim or counterclaim, including without limitation (i) any derivative action or proceeding brought on behalf of the us, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers or other employees to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the DGCL, or (iv) any action asserting a claim governed by the internal affairs doctrine, shall be a state or federal court located within the State of Delaware, in all cases subject to the court having personal jurisdiction over the indispensable parties named as defendants. While the Delaware courts have determined that such choice of forum provisions are facially valid, a stockholder may nevertheless seek to bring a claim in a venue other than those designated in the exclusive forum provisions. In such instance, we would expect to vigorously assert the validity and enforceability of the exclusive forum provisions of our Bylaws. This may require significant additional costs associated with resolving such action in other jurisdictions and there can be no assurance that the provisions will be enforced by a court in those other jurisdictions.

These exclusive forum provisions may result in increased costs for investors to bring a claim. Further, these exclusive forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers, or other employees, which may discourage lawsuits against us and our directors, officers and other employees. If a court were to find the exclusive-forum provision in our Bylaws to be inapplicable or unenforceable in an action, we may incur further significant additional costs associated with resolving the dispute in other jurisdictions, all of which could seriously harm our business.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A . The transfer agent’s address is 462 South 4th Street, Suite 1600, Louisville, Kentucky 40202, and its telephone number is (800) 962-4284.

Listing

Our common stock is listed on the NYSE American under the trading symbol “CATX.”