In Nigeria, the use of herbal medicines to complement diabetes treatment is common, though their impact on treatment outcomes is not well understood. This cross-sectional questionnaire study, conducted in Jos metropolis, Nigeria, assessed the prevalence of herbal medicines use among 141 diabetes patients and its relationship with treatment outcomes. Most of the study participants were females (60.3%) with a family history of diabetes (70%). The findings showed that 58.9% of participants used herbal remedies like Moringa oleifera, Vernonia amygdalina and Allium sativum to complement treatment for diabetes mellitus without guidance from conventional clinicians. There were higher incidences of hospitalizations and hypoglycemia in the group that complemented their treatments with herbal medicines (P <0.05). However, fasting blood glucose levels remained unaffected (P > 0.05). The study highlights the common use of herbal medicines in Nigeria and underscores both the prospect for herbal medicine integration and the challenges of poor clinical data to inform ration use.