Note 5 - Warrants and Equity (Tables)

12 Months Ended

Dec. 31, 2024

Notes Tables

Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]

	Number of Shares Under Outstanding Warrants at December 31, 2024		Number of Shares Under Outstanding Warrants at December 31, 2023		Weighted Average Exercise Price at December 31, 2024		Remaining Contractual Life at December 31, 2024 (Years)
Liability Classified Warrants (1)
Issued March 2019		—		17,573	$	—		—
Issued April 2019		—		58,336		—		—
Issued February 2020		67,670		67,670		94.50		0.6
Issued December 2023		939,316		939,316		2.57		4.8
Issued August 2024		5,056,054		—		2.24		3.4
		6,063,040		1,082,895	$	3.32
Equity Classified Warrants
Issued April 2020 - Consulting		—		1,112	$	—		—
Issued December 2020 - Consulting		556		556		70.80		1.0
Issued April 2021 - Consulting		4,767		4,767		54.45		1.3
Issued August 2021 - Consulting		16,667		16,667		46.20		6.6
Issued June 2022 - Consulting		3,334		3,334		22.35		7.5
Issued September 2022 - Consulting		16,667		16,667		18.60		7.7
Issued June 2023 - Consulting		10,001		10,001		9.00		8.5
Issued August 2023 - Consulting		6,667		6,667		9.30		3.6
Issued December 2023 - Pre-Funded Warrants		—		229,506		—		—
Issued March 2024 - Consulting		3,334		—		9.15		9.2
Issued August 2024 - Pre-Funded Warrants		1,649,000		—		0.001		n/a
Issued October 2024 - Consulting		36,000		—		2.36		9.8
		1,746,993		289,277	$	0.99
Balance outstanding		7,810,033		1,372,172	$	2.80

Schedule of Warrants or Rights, Assumptions Used [Table Text Block]

	Year Ended December 31,
	2024		2023
Risk-free interest rate		4.2% to 4.4%		3.8% to 5.4%
Volatility		76.9% to 99.4%		79.5% to 108.7%
Expected life (years)		0.6 to 4.8		0.3 to 5.0
Dividend yield		—%		—%

Schedule of Warrant Activity [Table Text Block]

	Number of Shares Under Warrant			Range of Warrant Exercise Price per Share	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)
Outstanding at December 31, 2023		1,082,895		9.60 to 157.50	$	24.32		5.1
Granted		5,056,054		2.23 to 2.79	$	2.24		3.4
Expired		(75,909	)	99.00 to 157.50	$	143.96		—
Outstanding at December 31, 2024		6,063,040		2.23 to 94.50	$	3.32		3.5
Vested and Exercisable at December 31, 2024		6,063,040		2.23 to 94.50	$	3.32		3.5