Note 2 - Summary of Significant Accounting Policies - Revenues and Accounts Receivable From Major Distribution Partners and Customers (Details) - Customer Concentration Risk [Member]	3 Months Ended			12 Months Ended
	Mar. 31, 2020		Mar. 31, 2019	Dec. 31, 2019
Revenue from Contract with Customer Benchmark [Member] | Avenova Direct [Member]
Distribution or collaboration partners	41.00%
Revenue from Contract with Customer Benchmark [Member] | Distributor A [Member]
Distribution or collaboration partners		[1]	26.00%
Revenue from Contract with Customer Benchmark [Member] | Distributor B [Member]
Distribution or collaboration partners		[1]	17.00%
Revenue from Contract with Customer Benchmark [Member] | Distributor C [Member]
Distribution or collaboration partners		[1]	14.00%
Accounts Receivable [Member] | Avenova Direct [Member]
Distribution or collaboration partners	12.00%			20.00%
Accounts Receivable [Member] | Distributor A [Member]
Distribution or collaboration partners	24.00%			28.00%
Accounts Receivable [Member] | Distributor B [Member]
Distribution or collaboration partners	10.00%			13.00%
Accounts Receivable [Member] | Distributor C [Member]
Distribution or collaboration partners	19.00%			19.00%

[1] Not greater than 10%