Following the report of beneficial effects of co-infection by GB virus C (GBV-C) for HIV-infected patients, we have studied synthetic GBV-C peptides and their relationship with HIV type-1. This paper reports the design and synthesis of new forms of presentation of two peptide inhibitors corresponding to the envelope proteins E1 and E2 of GBV-C, together with a study of their anti-HIV-1 activity. Homogeneous and heterogeneous multiple antigenic peptides (MAPs), lipophilic derivatizations, cyclization and peptide-gold conjugations are the chemical design strategies adopted. Our aim is to enhance the anti-viral potency of the GBV-C peptide domains. Of all the GBV-C peptide derivatives studied, peptide-gold complexes derived from the (22-39) sequence of the GBV-C E1 protein were the most active entry inhibitors. These results support the putative modulation of HIV-1 infection by the GBV-C E1 protein and open new perspectives for the development of novel peptide-derived HIV-1 entry inhibitors.