Introduction: It has been shown that growth hormone (GH) exerts regulatory effects on hemorheology and other metabolic functions. GH stimulates the production of insulin-like growth factor I (IGF-I) and GH-IGF-I system has profound effects on body fluid status. There are speculations that GH has become widely used as a performance enhancing drug among athletes of various sports. The present study evaluated the possible hemorheological effects of short term administration of human recombinant growth hormone (rhGH) in healthy young males. Methodology: Thirty young healthy males (27 ± 9) participated in a 29 days study where it was administered either 0.9% sodium chloride or 1 mg of human rhGH from day 1 to day 7. The participants were randomly assigned into either placebo (C) n = 15 or rhGH 1 mg/day (rhGH) group n = 15. This study evaluated plasma fibrinogen levels, red blood cell (RBC) aggregation, deformability and serum IGF-I levels between and within the groups along 29 days. Results: There was a significant increase in erythrocytes aggregation index post injection (day 8), in accordance to an increase in serum IGF-I.