this trial showed no significant difference of HCQ in outpatient setting
April 22, 2021 Effect of Early Treatment With Hydroxychloroquine or Lopinavir and Ritonavir on Risk of Hospitalization Among Patients With COVID-19 The TOGETHER Randomized Clinical Trial
Nov 2020 Do Zinc Supplements Enhance the Clinical Efficacy of Hydroxychloroquine?: a Randomized, Multicenter Trial
this trial showed no benefit adding Zinc
I am not saying these articles are decisive. for example, first article showed 10% improvement, below statistical significance. But to claim that there are no such studies is not correct.
Again, I would be curious to know how you came to conclusion that such studies do not exist –
did you check clinical trial database yourself; did you search duck-duck-go; or did you read this claim somewhere and accepted?