LAUSR

A multi-phase study was designed to examine the detectability of human growth hormone (GH) use in capillary dried blood spots (DBS). First, thirteen subjects self-injected a single, 2mg dose of somatropin and collected capillary DBS samples for 24 hours. Next, nine subjects self-injected 2mg somatropin, six times over the course of eleven days; DBS were collected intermittently following dosing. Finally, a non-drug, large-scale field study involved DBS collections from an athlete and staff population over three years. All DBS samples were self-collected using the Tasso M20 device and were analyzed for the presence of GH using the WADA-approved GH isoforms test. Following the single dose, positive detection within 12 hours of dosing was 86% and 56% sensitive on Kits 1 and 2, respectively. In the multi-dose study, detection within 12 hours was 85% and 69% sensitive on Kits 1 and 2, respectively. No positives were detected outside the 12-hour window following a single dose, wherein detection was 5.6% sensitive at 24-hours in the multi-dose study. Combining the 12-hour windows from both studies, 100% of samples had measurable recombinant (REC) and pituitary (PIT) GH concentrations above the assay LoD, 0.041 ng/mL. Finally, 1213 samples were collected in the large-scale field study: 189 showed REC and PIT concentrations above the LoD; none returned positive results. GH is detectable in capillary DBS using the isoforms method for 12-24 hours following use. While detection is short lived, transitioning to a DBS self-collection method can allow more frequent testing and increase deterrence to GH abuse.