Document And Entity Information - USD ($)	12 Months Ended
	Jul. 31, 2017	Oct. 10, 2017	Jan. 31, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jul. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Entity Registrant Name	OPIANT PHARMACEUTICALS, INC.
Entity Central Index Key	0001385508
Current Fiscal Year End Date	--07-31
Entity Filer Category	Smaller Reporting Company
Trading Symbol	OPNT
Entity Common Stock, Shares Outstanding		2,037,888
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 14,844,588