Chronic muscle pain is one of the most prevalent clinical challenges in sports medicine, significantly affecting training capacity, competitive performance, and quality of life in athletes.

The endocannabinoid system has emerged as a promising therapeutic target for pain modulation in the sports context.

This prospective, comparative, non-randomized observational study aims to evaluate whether adjuvant topical application of a cannabinoid balm (CBD:THC 3:1 - Papa & Barkley) provides additional reduction in chronic muscle pain intensity in athletes, compared to systemic CBD oil alone, over 90 days of follow-up in a real-world clinical practice setting.

Sixty adult athletes (amateur or professional) with established chronic muscle pain (≥3 months) who receive clinical indication for cannabinoid therapy will be followed in two observational cohorts: Cohort A (n=30), receiving only systemic CBD oil (60 mg/day oral/sublingual), and Cohort B, (n=30) receiving systemic CBD oil plus the topical cannabinoid balm (CBD:THC 3:1, applied twice daily to the affected muscle area).

Treatment allocation is based exclusively on the clinical decision of the principal investigator, reflecting routine medical practice. The primary outcome is the change in Brief Pain Inventory (BPI) scores from baseline (D0) to end of follow-up (D90). Secondary outcomes include pain intensity (NRS), sleep quality (PSQI), quality of life (SF-36), perceived muscle recovery (TQR scale), functional capacity (LEFS/UEFI), rescue analgesic use, and safety/tolerability of the topical formulation.

The study aims to generate real-world evidence on the effectiveness and safety of adjuvant topical cannabinoid therapy in athletes with chronic muscle pain in the Brazilian clinical practice setting.