DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2019	Feb. 28, 2019	Jul. 31, 2018
DOCUMENT AND ENTITY INFORMATION
Entity Registrant Name	BioPharmX Corp
Entity Central Index Key	0001504167
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 31, 2019
Current Fiscal Year End Date	--01-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 37.3
Entity Common Stock, Shares Outstanding		218,356,963
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2019
Trading Symbol	BPMX