Staywell are contractually bound by their terms to pay participants of their research studies in two installments; after 25 and 75 days, allowing up to 10 days processing and postage. I have not received any payments and the final payment was due on 8 July 2014. There have also been reports on yelp that when they finally paid some participants, their checks bounced.
http://www.yelp.com/biz/staywell-research-northridge
Stay away from these people.