Company: INTS
Filing Date: 2025-06-12
Form Type: 424B5
Source: 0001628280-25-031040
Chunk: 83

Company: INTENSITY THERAPEUTICS, INC.
Filing Date: 2025-06-12
Form: 424B5
Chunk 83
---
 is filed and not furnished;

• our Definitive Proxy Statement on Schedule 14A, filed with the SEC on June 4, 2024 (but only with respect to information required by Part III of our Annual Report on Form 10-K for the year ended December 31, 2023, which information updated and superseded information included in Part III of our Annual Report on Form 10-K for the year ended December 31, 2023); and

• the description of our common stock contained in our Registration Statement on Form 8-A filed with the SEC on November 30, 2021 , as amended on December 2, 2021 .

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial filing of the registration statement of which this prospectus is a part

<div align='center'>30</div>

and prior to effectiveness of such registration statement, until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus and will become a part of this prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

You may request, orally or in writing, a copy of any or all of the documents incorporated herein by reference. These documents will be provided to you at no cost, by contacting:

<div align='center'>Intensity Therapeutics, Inc.

1 Enterprise Drive, Suite 430

Shelton, CT 06484

(203) 221-7381

Attention: Joseph Talamo, Chief Financial Officer

31</div>

#### 6,675,000 Shares of Common Stock

### PROSPECTUS SUPPLEMENT
| ThinkEquity |

<div align='center'>June 11, 2025</div>