Profusa, Inc.

As filed with the Securities and Exchange Commission on April 28, 2026.

Registration No. 333-[●]

**UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

**FORMS-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

**626 Bancroft Way,

Suite A

Berkeley, CA 94710

(925) 997-6925

**(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Ben C. Hwang

Chief Executive Officer

**626 Bancroft Way,

Suite A

Berkeley, CA 94710

(925) 997-6925

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

**Ralph V. De Martino, Esq.

Marc Rivera, Esq.

ArentFox Schiff LLP

1717 K Street, NW

Washington, DC 20006

Phone: (202) 724-6847

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

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, please 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, 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 the provisions of 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 in this preliminary prospectus is not complete and may be changed. The selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell, nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED April 28, 2026.

PRELIMINARY PROSPECTUS

179,272,293 Shares of Common Stock for Resale by the Selling Stockholders

This prospectus relates to the resale, from time to time, by the Selling Stockholders identified in this prospectus under the caption “Selling Stockholders,” of up to 179,272,293 shares of common stock, par value $0.0001 per share, of the Company (the “Common Stock”), comprising:

In our registration statements, filed on August 22, 2025 (declared effective on August 25, 2025), October 9, 2025 (automatically effective on October 29, 2025 pursuant to Section 8(a) of the Securities Act of 1933), and February 17, 2026 (declared effective on February 17, 2026), we previously registered the resale of up to 119,611, 562,820 and 333,333 shares, respectively, by Ascent pursuant to the ELOC Purchase Agreement. This prospectus registers the resale of up to an additional 150,568,827 shares of Common Stock (the “Purchase Shares”) that we may, in our sole discretion, elect to sell to Ascent, from time to time over a period of up to 36 months from and after the Effective Date (defined below) pursuant to the ELOC Purchase Agreement. Ascent is deemed to be an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended, or the Securities Act.

The Ascent Conversion Shares to which this prospectus relates have been or may be issued by us to Ascent pursuant to a securities purchase agreement, dated as of February 11, 2025 and subsequently amended on August 25, 2025, December 22, 2025, December 29, 2025 and April 2, 2026, we entered into with Ascent, which we refer to in this prospectus as the PIPE Subscription Agreement. Pursuant to the PIPE Subscription Agreement, the Company has issued senior secured convertible promissory notes consisting of an initial tranche note in an aggregate principal amount of $10,000,000 on July 11, 2025, a second tranche note in the principal amount of $2,222,222 on September 30, 2025, a third tranche note in the principal amount of $555,555.55 on April 2, 2026, and a fourth tranche note in the principal amount of $1,111,111.11 on April 20, 2026. In addition, pursuant to the PIPE Subscription Agreement, the Company may request to sell additional convertible promissory notes (the “Additional Notes”) having an aggregate principal amount not to exceed $12,222,222 to Ascent for a purchase price that reflects at least a 10% original issue discount. The Additional Notes, together with the first, second, third, and fourth tranche notes that have already been issued as of the date of this prospectus, are referred to herein as the Ascent Notes. In our registration statement, filed on September 16, 2025 and declared effective on September 26, 2025, we previously registered the resale of up to 2,962,962 shares issuable upon conversion of the Ascent Notes. This prospectus registers the resale of up to an additional 20,027,859 Ascent Conversion Shares.

As an inducement for Ascent agreeing to execute Amendment No. 4 to the PIPE Subscription Agreement on April 2, 2026 and to participate in the closing of the third tranche note, the Company issued to Ascent a warrant dated April 20, 2026 to purchase 3,333,333 shares of Common Stock (the “Ascent Inducement Warrant”) at an initial exercise price of $0.50 per share, subject to adjustment. The Ascent Inducement Warrant may be exercised for cash or on a cashless basis and contains anti-dilution and fundamental transaction provisions. The Ascent Inducement Warrant is subject to a 120-day lock-up.

On or about April 27, 2023, the Company issued a promissory note (the “Sponsor Note”) to Sponsor for certain working capital needs in an amount of up to $2.5 million. The Sponsor Note was amended and restated on May 31, 2024 and amended on March 20, 2026. On April 24, 2026, the Company entered into a debt modification and conversion agreement (the “Modification Agreement”) pursuant to which the Sponsor may elect to convert the $1,869,796 principal balance under the note at any time or from time to time on or after the date of this prospectus at a conversion price equal to the greater of (a) 95% of the closing price of our Common Stock on the date that the Registration Statement of which this prospectus forms a part is declared effective and (b) a floor price of $0.35 per share subject to a 4.99% beneficial ownership limitation.

We are registering the offer and sale and/or resale of these securities to satisfy certain registration obligations we have and certain registration rights we have granted. The Selling Stockholders may offer all or part of the Resale Securities for resale from time to time through public or private transactions, at either prevailing market prices or at privately negotiated prices. The Resale Securities are being registered to permit the Selling Stockholders to sell Resale Securities from time to time, in amounts, at prices and on terms determined at the time of offering. The Selling Stockholders may sell the Resale Securities through ordinary brokerage transactions, in underwritten offerings, directly to market makers of our securities or through any other means described in the section entitled “Plan of Distribution” herein. In connection with any sales of Resale Securities offered hereunder, the Selling Stockholders, any underwriters, agents, brokers or dealers participating in such sales may be deemed to be “underwriters” within the meaning of the Securities Act, or the Exchange Act. We are registering the Resale Securities for resale by the Selling Stockholders, or their donees, pledgees, transferees, distributees or other successors**-**in-interest selling our Common Stock received after the date of this prospectus from the Selling Stockholders as a gift, pledge, partnership distribution or other transfer.

We will not receive any of the proceeds from the sale of Common Stock by the Selling Shareholders. However, we may receive up to $100,000,000 in aggregate gross proceeds from sales of the Purchase Shares to Ascent that we may, in our discretion, elect to make, from time to time after the date of this prospectus, pursuant to the Purchase Agreement. Additionally, we will receive proceeds from any cash exercise of the Ascent Inducement Warrants, which, if exercised in cash with respect to all of the 3,333,333 Ascent Inducement Warrant Shares would result in aggregate gross proceeds to us of $1,666,666.50; however, we cannot predict when and in what amounts or if the Ascent Inducement Warrants will be exercised and it is possible that the Warrants may be exercised on a cashless basis or may expire and never be exercised, in which case we would not receive any cash proceeds.

The Selling Stockholders may sell the shares of our Common Stock offered by this prospectus from time to time on terms to be determined at the time of sale through ordinary brokerage transactions or through any other means described in this prospectus under the caption*“Plan of Distribution.”* The shares of Common Stock may be sold at fixed prices, at market prices prevailing at the time of sale, at prices related to prevailing market price or at negotiated prices.

We will pay the expenses incurred in registering under the Securities Act the offer and sale of the shares of Common Stock to which this prospectus relates by the Selling Stockholders, including legal and accounting fees. See*“Plan of Distribution — Offer and Resale of Common Stock by the Selling Stockholders”* beginning on page 126.

Our Common Stock is listed on Nasdaq under the symbol “PFSA.” On April 23, 2026, the last sale price for our Common Stock as reported on Nasdaq was $0.60 per share.

On February 9, 2026, the Company effected a reverse stock split of all our outstanding shares of Common Stock at a ratio of 1-for-75 (the “Reverse Stock Split”). Unless the context expressly indicates otherwise, all references to share and per share amounts referred to herein give effect to the Reverse Stock Split.

We are a “smaller reporting company” as defined under the federal securities laws and an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”) and, as such have elected to comply with certain reduced public company disclosure and other requirements for this prospectus that are otherwise applicable to public companies. See further discussion below.

Investing in our securities involves a high degree of risk. See the section entitled*“Risk Factors”* appearing on page 10 of this prospectus for a discussion of information that should be considered in connection with an investment in our securities.

Neither the Securities and Exchange Commission nor any other regulatory body 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.

The date of this prospectus is__________, 2026

TABLE OF CONTENTS

You should rely only on the information contained in this prospectus or any amendment or supplement to this prospectus. This prospectus is an offer to sell only the securities offered hereby, but only under the circumstances and in jurisdictions where it is lawful to do so. Neither we nor the Selling Stockholders have authorized anyone to provide you with information different from that contained in this prospectus or any amendment or supplement to this prospectus. Neither we nor the Selling Stockholders take any responsibility for, or can provide any assurance as to the reliability of, any information other than the information in this prospectus or any amendment or supplement to this prospectus. The information in this prospectus or any amendment or supplement to this prospectus is accurate only as of its date, regardless of the time of delivery of this prospectus or any amendment or supplement to this prospectus, as applicable, or any sale of the securities offered by this prospectus. Our business, financial condition, results of operations and prospects may have changed since that date.

For Investors Outside the United States: The Selling Stockholders are offering to sell, and seeking offers to buy, the securities offered by this prospectus only in jurisdictions where offers and sales are permitted. Neither we nor the Selling Stockholders have done anything that would permit this offering or the possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the securities offered by this prospectus and the distribution of this prospectus outside of the United States.

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