The proliferation of supplements alongside their widespread and acclaimed benefits is an important clinical and socio-economic issue. The study aimed at assessing the safety and efficacy of cannabidiol (CBD) oil in users based on the drug’s clinical impact on chronic health conditions. A follow-up questionnaire was developed to relate telephone conversations with participants to EQ-5D and EQ-VAS instruments’ relevant data biweekly. Patients were divided into 9 groups (hypertensive, diabetic, arthritis, inflammatory/pain, glaucoma, cancer, peptic ulcer disease, epilepsy, and asthma) based on their previously diagnosed clinical conditions. Index scores were calculated with a follow-up period of 8 weeks. A total of 157 participants across southern Nigeria states were recruited for the study. The response rate was 75.8% with 119 participants (49, 41.2 % male and 70, 58.8 % females). The medical classifications of participants in the study were cardiology (13, 11%), endocrinology (16, 13%), gastroenterology (15, 13%), oncology (8, 7%), psychiatry (13, 11%), ophthalmology (9, 8%) and others (48, 40%). The hypertensive and diabetes groups revealed improved QoL based on the statistically significant higher EQ-5D indices relating to clinical manifestations over the follow-up periods compared with the baseline features. Other groups similarly presented statistically improved health-related QoL. The study revealed the safety and efficacy of CBD in the various groups studied.