Chronic cervical radiculopathy (CR) is a common cause of pain and disability in adults. The primary objective of our study was to evaluate the efficacy of a structured, multimodal rehabilitation program, with or without adjunct neurotrophic supplementation, in chronic cervical radiculopathy; secondarily, this study investigates which patients are most likely to benefit from neurotrophic supplementation and aims to assess effects on pain, cervical mobility, disability, and daily activities to guide individualized care. Patients and Methods: In this prospective, randomized controlled trial, 82 patients with chronic CR were allocated to a study group (SG, n = 42) receiving a three-month multimodal rehabilitation program plus daily neurotrophic supplementation (named PHSD) or a control group (CG, n = 40) receiving the same rehabilitation alone. Outcome measures included the Visual Analogue Scale (VAS), Neck Disability Index (NDI), cervical mobility indexes (CSI—Chin-Sternum Index; OWI—Occiput-Wall Index; TAI—Tragus-Acromion Index), and Katz ADL (Activity of Daily Living) Index, assessed at baseline and after three months. Results: Both groups showed significant improvements, but the SG demonstrated greater reductions in pain (median VAS change: 8.16 ± 0.72 vs. 5.11 ± 0.70, p < 0.001) and disability (mean NDI change: 24.71 ± 5.13 vs. 20.90 ± 4.49, p < 0.001). Cervical mobility indexes improved in both groups, with larger gains in the SG (p < 0.01), supporting the potential benefits of adding neurotrophic supplementation. Conclusions: A structured multimodal rehabilitation program significantly improves pain, mobility, and disability in chronic CR, while combining it with PHSD may enhance these effects. Further randomized trials are needed to confirm these findings and establish standardized conservative treatment protocols.