Human monkeypox virus became a burgeoning global health issue when outbreaks were identified in over 100 countries beginning in early 2022. We describe the case of a 38-year-old male with acquired immunodeficiency syndrome who presented one month after the development of painful anal lesions, subsequently confirmed to be monkeypox. The patient was unsuccessfully treated outpatient with multiple courses of oral tecovirimat before presenting to the emergency department for continual lesion progression. Given his AIDS, the patient was at-risk for poor response to oral treatment due to the potential for malabsorption from disruptions in his gut microbiome as well as inability to consume the recommended 25 grams of fat per dose needed for absorption. The identification of patients at-risk for severe disease is imperative as this population may be better suited for intravenous tecovirimat treatment due to the difficult parameters required for optimal absorption of oral therapy.