| Cover | Dec. 15, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | On December 21, 2023, Onconetix, Inc. (the “Company”) filed a Current Report on Form 8-K (the “Original Form 8-K”) with the Securities and Exchange Commission in connection with the Company’s acquisition of Proteomedix AG (“Proteomedix”), which Original Form 8-K was amended on December 27, 2023 and February 27, 2024 to, among other things, include the historical audited and interim financial statements of Proteomedix required by Item 9.01(a) of Form 8-K (the “Proteomedix Financial Statements”) and the pro forma combined financial information required by Item 9.01(b) of Form 8-K that were not included in the Original Form 8-K (together with the Proteomedix Financial Statements, the “Proteomedix Financial Information”) in reliance on the instructions to such item. This Amendment No. 3 on Form 8-K/A further amends the Original Form 8-K to add as an exhibit required by Item 9.01(d) a consent from BDO AG, Proteomedix’s independent registered public accounting firm (“BDO”) to incorporate by reference BDO’s audit report included in the Proteomedix Financial Information into certain of the Company’s registration statements. Except as described above, all other information in the Original Form 8-K remains unchanged. |
| Document Period End Date | Dec. 15, 2023 |
| Entity File Number | 001-41294 |
| Entity Registrant Name | Onconetix, Inc. |
| Entity Central Index Key | 0001782107 |
| Entity Tax Identification Number | 83-2262816 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 201 E. Fifth Street |
| Entity Address, Address Line Two | Suite 1900 |
| Entity Address, City or Town | Cincinnati |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 45202 |
| City Area Code | 513 |
| Local Phone Number | 620-4101 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.00001 per share |
| Trading Symbol | ONCO |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
