Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Reserved for Future Issuance

Schedule of common stock reserved for future issuance

	December 31,	December 31,
	2021	2020
Series X Preferred Stock	5,242,501	—
Warrants for the purchase of common stock	1,530,380	1,032,291
Options outstanding to purchase common stock	1,346,733	227,846
Options available for future issuance to purchase common stock	1,633,736	322,695
Shares reserved for the employee stock purchase plan	30,904	24,825
Total	9,784,254	1,607,657

Summary of Series X preferred stock or warrants to purchase

The following table presents information about warrants that are issued and outstanding at December 31, 2021:

Year Issued	Equity Instrument	Warrants Outstanding	Exercise Price		Date of Expiration
2015	Common Stock	204	$	732.72	3/30/2022
2018	Common Stock	699,962	$	72.00	6/21/2023
2019	Common Stock	331,858	$	37.50	2/7/2024
2021	Common Stock	498,356	$	2.10	12/14/2030
Total		1,530,380
Weighted average exercise price			$	41.84
Weighted average life in years					4.05