In the recent US-Core ballot, there was an issue raised about the use of the MedicationRequest and MedicationStatement. The resolution to that issue effectively changed the scope of the MedicationRequest resource.

The MedicationRequest resource is an Order resource and represents an actual order for a medication for a patient. It can be "patient-reported" but that is just the patient reporting that they received an order for a medication that might not have been formally ordered in a clinician's system.

It definitely can not be used to represent what is more commonly understood as a "Patient-reported medication" which is when a patient wants to communicate "I am taking/plan to take/did take this medication". That is the scope of the MedicationStatement resource which is an Event resource.