Organization and Basis of Presentation	9 Months Ended
Organization and Basis of Presentation	Sep. 30, 2017
Organization And Basis Of Presentation [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Evoke Pharma, Inc. (the “Company”) was incorporated in the state of Delaware in January 2007. The Company is a publicly-held specialty pharmaceutical company focused primarily on the development of drugs to treat gastroenterological disorders and disease. Since its inception, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure, and has not realized revenues from its planned principal operations. The Company does not anticipate realizing revenues for the foreseeable future. The Company’s activities are subject to the significant risks and uncertainties associated with any specialty pharmaceutical company that has substantial expenditures for research and development, including funding its operations. Going Concern The Company has incurred recurring losses and negative cash flows from operations since inception and expects to continue to incur net losses for the foreseeable future until such time, if ever, that it can generate significant revenues from the sale of its sole product, Gimoti™. The Company ended the third quarter of 2017 with approximately $10.4 million in cash and cash equivalents, and the Company anticipates that it will continue to incur losses from operations due to its plans to fund additional clinical development, including the analysis of data from the comparative exposure pharmacokinetic (“PK”) clinical trial, completion of a planned new drug application (“NDA”) submission for Gimoti, pre-approval and pre-commercialization activities, including marketing and manufacturing of Gimoti, and support its general and administrative costs to support operations. As a result, the Company believes that there is substantial doubt about its ability to continue as a going concern for one year after the financial statements are issued. The determination as to whether the Company can continue as a going concern contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. In its report on the Company’s financial statements for the year ended December 31, 2016, the Company’s independent registered public accounting firm included an explanatory paragraph expressing substantial doubt regarding the Company’s ability to continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company’s net losses may fluctuate significantly from quarter to quarter and year to year. The Company believes that its current cash and cash equivalents will be sufficient to meet estimated working capital requirements and fund operations through at least June 2018. The Company will need to raise additional debt or equity financing to fund future operations. There can be no assurance that additional financing will be available when needed on acceptable terms. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, and/or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations, financial condition and future prospects.