If the hunt on Craigslist is not helping you find additive benefits to your income, you may consider other means. While in the clinical trial phase, medical and pharmaceutical companies offer clinical trial services. A couple websites provide search functions that permit easy access to a number of different studies that are being researched in your vicinity.
If you have a disease, dysfunction or simply the desire to test the latest drugs or techniques in medicine you may be interested in these resources. For your time, effort, and willingness to participate in clinical trials, companies are willing to compensate financially with cash. Clinical trial jobs are available to those who are willing.
These offerings are commonly worth hundreds of dollars depending on the length and participation of the study. Many do not post how much they are willing to pay, but if you contact the companies they can provide more information.