Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Taxes

Schedule of reconciliation of statutory federal income tax rate

	Year Ended December 31,
	2018		2017
Tax at statutory federal rate	(21.0)	%	(34.0)	%
State taxes, net of federal benefit	(1.7)		(1.4)
Stock-based compensation	1.5		(0.8)
Nondeductible executive compensation	0.9		—
Change in valuation allowance	20.6		(34.2)
Federal tax rate change	—		70.2
Other	(0.3)		0.2
Provision for income taxes	(0.0)	%	(0.0)	%

Schedule of tax effects of temporary differences and carryforwards

The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands):

	December 31,
	2018		2017
Deferred tax assets:
Net operating loss carryforwards	$	25,359	$	22,586
Inventory		1,442		1,520
Accruals		760		401
Depreciation and amortization		88		60
Limitation on business interest		96		—
Stock-based compensation		1,416		1,228
Gross deferred tax assets		29,161		25,795
Valuation allowance		(29,073)		(25,721)
Deferred tax assets		88		74
Deferred tax liabilities:
Prepaid expenses		(88)		(74)
Deferred tax liabilities		(88)		(74)
Net deferred tax assets	$	—	$	—