A Look at Usana Health Services for Resellers and for Customers. Usana Health Sciences are an interesting company with a long history, who dominated the vitamin scene even as recently as a decade ago. They had a high share value, and they had a presence in more than a dozen countries. But, more recently, Usana Health Sciences reviews have been mixed. They became the subject of a probe by the Securities and Exchange Commission back in 2007, who were concerned that their sales practices were less than perfect.