Company: SHPH
Filing Date: 2025-04-21
Form Type: DEFR14A
Source: 0001641172-25-005474
Chunk: 0

Company: Shuttle Pharmaceuticals Holdings, Inc.
Filing Date: 2025-04-21
Form: DEFR14A
Chunk 0
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<div align='center'>UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule 14a - 101)

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934</div>

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

| ☐ | Preliminary                                                         
 Proxy Statement                                                     |
| ☐ | Confidential,                                                       
 for Use of the Commission Only (as permitted by Rule 14a - 6(e)(2)) |
| ☒ | Definitive                                                          
 Proxy Statement                                                     |
| ☐ | Definitive                                                          
 Additional Materials                                                |
| ☐ | Soliciting                                                          
 Material Pursuant to §240.14a - 12                                  |

<div align='center'>SHUTTLE PHARMACEUTICALS HOLDINGS, INC.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)</div>

Payment of Filing Fee (Check all boxes that apply):

| ☒ | No                                                                                              
 fee required                                                                                    |
| ☐ | Fee                                                                                             
 paid previously with preliminary materials                                                      |
| ☐ | Fee                                                                                             
 computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a–6(i)(1) and 0–11 |

<div align='center'>Explanatory Note</div>

This Amendment No. 1 to Schedule 14A (this “Amendment”)
is being filed to amend and replace the Definitive Proxy Statement filed by Shuttle Pharmaceuticals Holdings, Inc. (the “Company”)
with the Securities and Exchange Commission on March 31, 2025 (the “Proxy Statement”). After filing the original
Proxy Statement, the Company determined that it needed to include an additional matter to be voted on by stockholders. Therefore,
this Amendment is being filed herewith to add in Proposal No. 6, approval of an issuance in excess of 19.99% of the Company’s common
stock at a price less than the “Minimum Price” as defined in Nasdaq Listing Rule 5635(d) to allow for the conversion of convertible
notes issued to investors in the Company’s October 2024 convertible note and warrant offering. In addition, this Amendment No.
1 modifies Proposal No. 4 to increase the range and