Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Sep. 30, 2023
Feb. 14, 2024
Mar. 31, 2023
Document Information [Line Items]      
Entity, Registrant Name ARCH THERAPEUTICS, INC.    
Document, Type 10-K/A    
Document, Annual Report true    
Document, Period End Date Sep. 30, 2023    
Current Fiscal Year End Date --09-30    
Document, Fiscal Period Focus FY    
Document, Fiscal Year Focus 2023    
Document, Transition Report false    
Entity, File Number 000-54986    
Entity, Incorporation, State or Country Code NV    
Entity, Tax Identification Number 46-0524102    
Entity, Address, Address Line One 235 Walnut Street, Suite 6    
Entity, Address, City or Town Framingham    
Entity, Address, State or Province MA    
Entity, Address, Postal Zip Code 01702    
City Area Code 617    
Local Phone Number 431-2313    
Title of 12(g) Security Common Stock, par value $0.001 per share    
Entity, Well-known Seasoned Issuer No    
Entity, Voluntary Filers No    
Entity, Current Reporting Status Yes    
Entity, Interactive Data, Current Yes    
Entity, Filer Category Non-accelerated Filer    
Entity, Small Business true    
Entity, Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document, Financial Statement Error Correction Flag false    
Entity, Shell Company false    
Entity, Public Float     $ 4,000,000
Entity, Common Stock Shares, Outstanding   4,742,363  
Auditor Name Weinberg & Company, P.A.    
Auditor Location Los Angeles, California    
Auditor Firm ID 572    
Amendment Description Arch Therapeutics, Inc. (the “Company”) is filing this Amendment No. 1 (this “Amendment”) to its Annual Report on Form 10-K for the fiscal year ended September 30, 2023, which was originally filed with the Securities and Exchange Commission (“SEC”) on February 15, 2024 (the “Form 10-K”) solely to correct and replace the disclosure in connection with the beneficial ownership of shares and voting power held by certain shareholders, directors, and officers included in Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.   Except for the items described above or contained in this Amendment, this Amendment continues to speak as of the date of the Form 10-K, and does not modify, amend or update any other item or disclosures in the Form 10-K, including the financial information. Accordingly, this Amendment should be read in conjunction with the Form 10-K and the Company’s other filings with the SEC.    
Amendment Flag true    
Entity, Central Index Key 0001537561