Nuwellis, Inc.

S-11 ny20073226x1_s1.htm S-1

As filed with the Securities and Exchange Commission on May 22, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

John L. Erb

Chief Executive Officer

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after the effective date of this registration statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

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

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission acting pursuant to said Section 8(a), may determine.

The information contained in this preliminary prospectus is not complete and may be changed. We may not sell these securities until the registration statement relating to these securities filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and they are not soliciting an offer to buy these securities in any jurisdiction where any such offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED May 22, 2026

PRELIMINARY PROSPECTUS

Up to 4,854,369 Shares of Common Stock

or

Pre-Funded Warrants to Purchase up to 4,854,369 Shares of Common Stock,

Series C Common Warrants to Purchase up to 4,854,369 Shares of Common Stock,

Series D Common Warrants to Purchase up to 4,854,369 Shares of Common Stock

and

Placement Agent Warrants to Purchase up to 145,631 Shares of Common Stock

Up to 14,708,738 Shares of Common Stock Issuable Upon Exercise of the Pre-Funded Warrants,

Series C Common Warrants, Series D Common Warrants and Placement Agent Warrants

We are offering, on a reasonable best efforts basis up to 4,854,369 shares of common stock (“common stock” or “Common Stock”), Series C common warrants (“Series C common warrants”) to purchase up to 4,854,369 shares of common stock and Series D common warrants (“Series D common warrants”, and together with the Series C common warrants, the “common warrants”) to purchase up to 4,854,369 shares of common stock at an assumed combined public offering price of $1.03 per share and accompanying common warrants, which was the last reported sale price of our common stock on the Nasdaq Capital Market (“Nasdaq”) on May 13, 2026. Each common warrant will have an exercise price of $ , and will be exercisable beginning on the effective date of stockholder approval of the issuance of the shares upon exercise of the common warrants (the “Warrant Stockholder Approval”), provided however, if the Pricing Conditions (as defined below) are met, the Warrant Stockholder Approval will not be required and the common warrants will be exercisable upon issuance (the “Initial Exercise Date”). The Series C common warrants and the Series D common warrants will expire eighteen months and five years, respectively, from the Initial Exercise Date or the Warrant Stockholder Approval, as applicable. As used herein “Pricing Conditions” means that the combined public offering price per share and accompanying common warrants is such that the Warrant Stockholder Approval is not required under the rules of The Nasdaq Stock Market LLC because either (i) the offering is an at-the-market offering under the rules of Nasdaq (the “Nasdaq Rules”) and such price equals or exceeds the sum of (a) the applicable “Minimum Price” per share under Nasdaq Rule 5635(d) plus (b) $0.125 per whole share of common stock underlying the Series C common warrants and Series D common warrants or (ii) the offering is a discounted offering where the pricing and discount (including attributing a value of $0.125 per whole share underlying the common warrants) meet the pricing requirements under the Nasdaq Rules. The shares of our common stock and the common warrants are immediately separable and will be issued separately, but they will be purchased together in this offering.

We are also offering to certain purchasers whose purchase of shares of common stock in this offering would otherwise result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock immediately following the consummation of this offering, the opportunity to purchase, if any such purchaser so chooses, pre-funded warrants to purchase shares of common stock (the “pre-funded warrants”), in lieu of shares of common stock. The purchase price of each pre-funded warrant (and accompanying common warrants) will be equal to the public offering price for the common stock (and accompanying common warrants) in this offering, minus $0.0001.

Each pre-funded warrant is exercisable for one share of our common stock and has an exercise price of $0.0001 per share. For each pre-funded warrant that we sell, the number of shares of common stock we are offering will be reduced on a one-for-one basis. Each pre-funded warrant will be exercisable at any time after the date of issuance and will not expire until exercised in full.

The common stock (or pre-funded warrants) and the common warrants will be sold in combination, with each share of common stock (or pre-funded warrant to purchase one share of common stock) accompanied by common warrants each to purchase one share of our common stock. This prospectus also relates to the offering of common stock issuable upon exercise of the pre-funded warrants and common warrants. We collectively refer to the shares of common stock, pre-funded warrants and common warrants offered hereby, including the shares of common stock underlying the pre-funded warrants and common warrants, as the “securities.”

The securities will be offered at a fixed price and are expected to be issued in a single closing. This offering will terminate on June 30, 2026, unless the offering is fully subscribed before that date or we decide to terminate the offering (which we may do at any time in our discretion) prior to that date. We will deliver all securities to be issued in connection with this offering delivery versus payment or receipt versus payment, as the case may be, upon our receipt of investor funds. Accordingly, neither we nor the placement agent have made any arrangements to place investor funds in an escrow account or trust account since the placement agent will not receive investor funds in connection with the sale of the securities offered hereunder.

We have engaged Ladenburg Thalmann & Co. Inc., (the “placement agent”), to act as our exclusive placement agent in connection with this offering. The placement agent may be deemed to be an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended. The placement agent has agreed to use its reasonable best efforts to arrange for the sale of the securities offered by this prospectus. The placement agent is not purchasing or selling any of the securities we are offering and the placement agent is not required to arrange the purchase or sale of any specific number of securities or dollar amount. We have agreed to pay to the placement agent the placement agent fees set forth in the table below. There is no arrangement for funds to be received in escrow, trust or similar arrangement. There is no minimum offering requirement as a condition of closing of this offering. We may sell fewer than all of the securities offered hereby, which may significantly reduce the amount of proceeds received by us. Because there is no escrow account and no minimum number of securities or amount of proceeds, investors could be in a position where they have invested in us, but we have not raised sufficient proceeds in this offering to adequately fund the intended uses of the proceeds as described in this prospectus.

Our common stock is listed on Nasdaq under the symbol “NUWE.” On May 13, 2026, the last reported sale price of our common stock on Nasdaq was $1.03 per share. The actual public offering price per share of common stock and accompanying common warrants will be determined between us, the placement agent, and the investors in the offering at the time of pricing and may be at a discount to the assumed public offering price. Therefore, the assumed public offering price used throughout this prospectus may not be indicative of the final public offering price. All share numbers included in this prospectus are based upon an assumed public offering price of $1.03 the closing price of our common stock on Nasdaq on May 13, 2026. There is no established trading market for the pre-funded warrants or common warrants, and we do not expect a market to develop. We do not intend to apply for a listing of the pre-funded warrants or common warrants on any securities exchange or other nationally recognized trading system. Without an active trading market, the liquidity of the pre-funded warrants or common warrants will be limited.

We have agreed to issue to the placement agent, or its designees, warrants to purchase the number of shares of common stock equal to 3.0% of the aggregate number of shares of common stock and/or pre-funded warrants sold in this offering (the “Placement Agent Warrants”). The Placement Agent Warrants will have an exercise price of $ (equal to 165% of the combined public offering price per share of common stock and accompanying common warrants) and will be exercisable for five years from the commencement of sales of the offering.

Delivery of securities to purchasers in the offering is expected to be made on or about , 2026, subject to the satisfaction of customary closing conditions.

We are a “smaller reporting company” as defined under U.S. federal securities laws and, as such, have elected to comply with reduced public company reporting requirements. See “Prospectus Summary — Implications of Being a Smaller Reporting Company.” This prospectus complies with the requirements that apply to an issuer that is a smaller reporting company.

An investment in our securities involves a high degree of risk. Before making any investment decision, you should carefully read the discussion of the material risks of investing in our securities in “Risk Factors” beginning on page 6 of this prospectus and under similar headings in any amendment or supplement to this prospectus or in any filing with the Securities and Exchange Commission that is incorporated by reference herein.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Ladenburg Thalmann

The date of this prospectus is , 2026