It is widely accepted that extracts of St. John’s wort (Hypericum perforatum) improve depressive symptoms, and tinnitus patients commonly presented with either mild depression or anxiety. We investigated whether co-administration of St. John’s wort andGinkgo bilobaextracts can suppress tinnitus. Participants with subjective tinnitus aged 30–70 years were randomly assigned to the experimental (co-administration of St. John’s wort andGinkgo bilobaextract; n = 20) or control (Ginkgo bilobaextract only; n = 26) group for 12 weeks. Participants were blinded to the group assignments. After 12 weeks of treatment, no significant change in the minimum masking level on the tinnitogram was observed in either group. In the co-administration group, the Tinnitus Handicap Inventory (THI) score decreased from 34.7 (SD, 15.9) to 29.6 (16.0) (p= 0.102). However, the control group showed a significant decrease in THI score, from 30.5 (16.7) to 25.6 (17.1) (p= 0.046). Regarding the Short Form-36 Health Survey (SF-36), only the “Social Functioning” domain score changed significantly after extract co-administration, from 74.5 (21.5) to 83.9 (20.5) (p= 0.047). Co-administration of St. John’s wort andGinkgo bilobaextracts did not improve the symptoms of subjective tinnitus compared to administration ofGinkgo bilobaextract alone.