Nutraceutical Supplementation Combined With Physiotherapy for Rotator Cuff Tendinopathy

Rotator cuff tendinopathy is a common cause of shoulder pain and functional impairment. Exercise-based physiotherapy represents a cornerstone of conservative treatment, while nutraceutical supplementation has been proposed as a potential adjunctive strategy. This prospective, randomized, assessor-blinded study evaluated the effects of adding a nutraceutical formulation containing bioactive collagen peptides, astaxanthin, trans-resveratrol, and vitamin C (Doltendix®) to physiotherapy in patients with rotator cuff tendinopathy without partial- or full-thickness tendon tears. Forty-two participants were randomly allocated in a 1:1 ratio to physiotherapy plus nutraceutical supplementation or physiotherapy alone. Pain, shoulder function, upper-limb disability, and health-related quality of life were assessed over a 120-day follow-up period

Inclusion Criteria: * Age between 18 and 60 years. * Clinical diagnosis of rotator cuff tendinopathy assessed by musculoskeletal ultrasonography, with magnetic resonance imaging performed when clinically required to exclude tendon tears. * Shoulder pain lasting at least 3 months. * Visual Analog Scale (VAS) pain score greater than 4 at enrollment. * Previous physiotherapy for rotator cuff tendinopathy for at least 1 month before enrollment. Exclusion Criteria: * Partial- or full-thickness rotator cuff tear. * Other causes of shoulder pain, including acromioclavicular osteoarthritis, adhesive capsulitis, or subacromial bursitis. * Previous proximal humeral or glenoid fracture. * Rheumatologic disease. * Psychiatric disease. * Cardiovascular disease. * Renal or hepatic failure. * Pregnancy. * Known hypersensitivity to one or more components of the nutraceutical formulation. * Treatment with antiepileptic, anticoagulant, antidepressant, or opioid medications.