See answer here - https://ttlc.intuit.com/community/retirement/discussion/income-question-does-income-from-a-medical-s...
Income for participating in a clinical trial or medical study is taxable. If the activity is infrequent, the income would not be self-employment income. The IRS discussed that position in the Internal Revenue Service's Private Letter Ruling 9106004 regarding a participant in a medical study for asthma.
What that means is that it would be subject to income taxes, but not subject to self-employment tax. It also would not qualify the participant for the earned income tax credit or any other tax benefit that is dependent on earned income such as an IRA deduction.
