CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating expenses:
Research and development	$ 34,996	$ 27,045	$ 66,755	$ 35,137
General and administrative	4,571	920	12,527	2,657
Total operating expenses	39,567	27,965	79,282	37,794
Loss from operations	(39,567)	(27,965)	(79,282)	(37,794)
Other income (expense):
Interest expense	(239)	(93)	(906)	(93)
Interest income	10		10
Change in fair value of warrant liability	(2,426)	2	(5,509)	2
Change in fair value of derivative liability		(129)	512	(105)
Change in fair value of contingent equity liability			(13,082)
Loss from equity method investment	(638)	(75)	(1,204)	(75)
Total other income (expense), net	(3,293)	(295)	(20,179)	(271)
Loss before provision for income taxes	(42,860)	(28,260)	(99,461)	(38,065)
Provision for income taxes	55		647
Net loss and comprehensive loss	(42,915)	(28,260)	(100,108)	(38,065)
Net (income) loss attributable to non-controlling interests		50		69
Accretion of beneficial conversion feature on Series A preferred shares			(12,006)
Net loss attributable to common shareholders of Biohaven Pharmaceutical Holding Company Ltd.	$ (42,915)	$ (28,210)	$ (112,114)	$ (37,996)
Net loss per share attributable to common shareholders of Biohaven Pharmaceutical Holding Company Ltd.-basic and diluted	$ (1.19)	$ (2.16)	$ (4.47)	$ (3.05)
Weighted average common shares outstanding-basic and diluted	35,930,698	13,050,446	25,102,920	12,447,153