Use shoulder studies to ask what people actually felt

Ask whether people hurt less or moved better

Human research comparing PRP with cortisone often found similar relief early on. Some reviews found slightly less soreness or easier arm use around six months. Other reviews found that the difference was too small for people to notice.

Early and later results aren't always the same. An average result also can't predict exactly how your shoulder will respond. Ask whether people slept, dressed, reached, or lifted more easily after treatment.

Keep results from surgery tied to surgery

PRP has also been used during repair of the rotator cuff, the muscles and tendons surrounding the shoulder. In those human studies, later scans showed fewer repaired tendons torn again. People didn't always report less soreness or easier use.

That finding belongs to an operation where a surgeon repaired the tendon. It doesn't prove that an office procedure rebuilds a tendon that never had surgery. The type of care matters as much as the treatment name.

Match a scan finding with the exam

Shoulder scans often show wear or small tears in people who feel no soreness. A tear matters more when it matches weakness, lost movement, and the clinician's exam. A scan by itself doesn't identify why you hurt.

A scan is useful when someone claims that tissue inside the shoulder grew or healed. Less soreness must be measured by what people feel and can do. One result shouldn't be used as proof of the other.

Sources

1. A 2026 meta-analysis of 10 randomized trials (n=591) found PRP and corticosteroid indistinguishable at 3-6 weeks and 3 months, with PRP pulling ahead at 6 months: ASES +10.8 (95% CI 4.71-16.80), Constant-Murley +10.7 (1.21-20.27) and VAS pain -0.8 (-1.45 to -0.18), plus fewer adverse events (RR 0.66, 0.44-0.99). The authors describe the benefit as statistically significant but CLINICALLY MODEST.

   Yuwarungsikul C, et al. — Platelet-rich plasma provides modest but durable functional benefit over corticosteroid for rotator cuff tendinopathy: A systematic review and meta-analysis of randomized controlled trials.. Knee Surg Sports Traumatol Arthrosc, 2026. DOI: 10.1002/ksa.70416.

2. A meta-analysis of nine randomized trials (469 patients) found corticosteroid superior to PRP in the SHORT term on Constant, Simple Shoulder Test and ASES scores, no difference at mid-term, and PRP superior in the LONG term on Simple Shoulder Test and ASES. The authors state explicitly that none of these differences reached the minimal clinically important difference.

   Peng Y, et al. — Comparison of the effects of platelet-rich plasma and corticosteroid injection in rotator cuff disease treatment: a systematic review and meta-analysis.. J Shoulder Elbow Surg, 2023. DOI: 10.1016/j.jse.2023.01.037.

3. A meta-analysis of 36 randomized trials and 2,443 patients found that PRP used as augmentation during surgical rotator cuff repair significantly REDUCES the retear rate (p<0.001) while producing NO benefit on any clinical outcome at short or medium/long term; PRP injected in conservatively treated patients showed no clear advantage at all, with high heterogeneity.

   Feltri P, et al. — Platelet-rich plasma does not improve clinical results in patients with rotator cuff disorders but reduces the retear rate. A systematic review and meta-analysis.. Knee Surg Sports Traumatol Arthrosc, 2023. DOI: 10.1007/s00167-022-07223-9.

4. A systematic review and meta-analysis of randomized trials found that augmenting arthroscopic rotator cuff repair with platelet-rich plasma reduces the retear rate and improves clinical function scores, whereas platelet-rich FIBRIN gives no clinically meaningful benefit - with the authors cautioning about the small number and heterogeneity of studies. The shoulder's best biologic evidence is for PRP used ALONGSIDE a repair operation, not as a substitute for one.

   Peng Y, et al. — Efficacy of platelet-rich plasma and platelet-rich fibrin in arthroscopic rotator cuff repair: A systematic review and meta-analysis.. PM & R : the journal of injury, function, and rehabilitation, 2023. DOI: 10.1002/pmrj.13049.

5. FDA states verbatim that stem cell, stromal vascular fraction, umbilical cord blood, Wharton's jelly, amniotic fluid and exosome products 'have [not] been approved for the treatment of any orthopedic condition, such as osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain, or shoulder pain.' The only FDA-approved stem cell products in the United States are blood-forming (hematopoietic progenitor) cells from umbilical cord blood, approved only for disorders of blood production, and there are currently NO FDA-approved exosome products.

   U.S. Food and Drug Administration — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. FDA (Center for Biologics Evaluation and Research), 2020.

6. FDA states plainly that no stem cell, exosome, stromal vascular fraction, umbilical cord blood, Wharton's jelly or amniotic-fluid product has been approved for the treatment of ANY orthopedic condition - it names osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain and shoulder pain individually. The only FDA-approved stem cell products in the United States are cord-blood-derived blood-forming stem cells for disorders of the hematopoietic system, and there are currently no FDA-approved exosome products.

   US Food and Drug Administration, Center for Biologics Evaluation and Research — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. FDA, 2020.

7. In a nationally representative Finnish population sample of 602 adults aged 41-76 who had bilateral 3-Tesla shoulder MRI regardless of symptoms, rotator cuff abnormalities were found in 98.7% of participants (25% tendinopathy, 62% partial-thickness tear, 11% full-thickness tear). Abnormalities were present in 96% of ASYMPTOMATIC shoulders. Only full-thickness tears were more common in symptomatic shoulders, and that difference all but disappeared after adjustment (absolute difference 0.8%, 95% CI -3.4% to 6.0%).

   Ibounig T, et al. — Incidental Rotator Cuff Abnormalities on Magnetic Resonance Imaging.. JAMA Intern Med, 2026. DOI: 10.1001/jamainternmed.2025.7903.

8. A four-arm, multicentre, single-blind phase 2/3 randomized trial of 480 knee OA patients (KL II-IV) compared autologous bone marrow aspirate concentrate, autologous adipose stromal vascular fraction and allogeneic umbilical-cord-tissue mesenchymal stromal cells against a corticosteroid injection control. At 12 months NONE of the three orthobiologic injections was superior to another, or to the corticosteroid control, and none of the four groups showed a significant change in MRI osteoarthritis score from baseline. No procedure-related serious adverse events occurred.

   Mautner K, et al. — Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial.. Nature medicine, 2023. DOI: 10.1038/s41591-023-02632-w.

9. A 2026 systematic review and meta-analysis of 28 randomized trials of intra-articular mesenchymal stem cell-based therapies in knee OA found significant improvements in several pain and function measures (delta-VAS MD -1.67; KOOS pain MD 15.37) but NO significant difference in WOMAC, KOOS quality of life or the Lequesne index, and MRI-based WORMS scores were non-significant - indicating no consistent structural benefit. Its own conclusion: these therapies serve a primarily SYMPTOM-modifying rather than STRUCTURE-modifying role, with higher frequencies of local reactions to weigh against the symptomatic benefit.

   Awad G, et al. — Efficacy and safety of intra-articular mesenchymal stem cell-based therapies in knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials.. Clinical rheumatology, 2026. DOI: 10.1007/s10067-026-08042-w.