Why Disc Research Is Its Own Field
Discogenic low back pain, the pain that research links to the intervertebral disc, has limited treatments.[1] Researchers have tried cell-based injections into the disc, which are theorized to have regenerative properties, to see whether they ease pain and disability without surgery.[1] The evidence is not yet well defined.[1] This guide reports what the studies measured and found, including the results that did not favor the cells.
For a plain-language introduction to the cells, read what stem cells are and what mesenchymal stem cells are on the GIOSTAR blog.
What the Reviews Find
A 2022 systematic review of intradiscal biologic treatments, which include stem cells and platelet-rich plasma, identified 12 studies and rated the overall evidence as very low. Its authors noted that a single stem cell trial in that set was negative.[1]
A 2023 meta-analysis of nine studies with 245 patients found that mesenchymal stem cell therapy significantly improved pain and Oswestry Disability Index scores. Its heterogeneity was 98%, which means the studies differed widely from one another.[2]
A 2018 systematic review and meta-analysis pooled six studies that had no control group. Pooled pain and disability scores improved, with heterogeneity of 99.4%, and no related adverse effects were reported. Because the design was single-arm, the authors called for randomized, double-blind trials with adequate sample sizes.[3]
A 2024 systematic review and meta-analysis of intradiscal regenerative therapies pooled randomized and observational studies. It rated the evidence as fair (Level III), with limited certainty, and noted a paucity of high-quality studies. Because it pooled platelet-rich plasma studies with stem cell studies, its conclusion is not specific to stem cells, so this guide does not report that conclusion.[4]
A 2026 meta-analysis of seven randomized trials found that mesenchymal stem cell injection reduced pain more than sham or placebo injection, with a mean difference of 6.67 points on visual analogue scale pain scores (95% confidence interval 4.02 to 9.31, in magnitude), and modest improvements in disability. It found no significant difference in treatment-emergent or serious adverse events. Its authors described the gains as modest.[5]
The Randomized Trials
Several randomized trials report mixed results.[6][7][8][9][10]
- RESPINE, 2024. This multicenter trial randomized 114 people with chronic low back pain to one injection of allogeneic bone marrow stromal cells or a sham procedure. The primary outcome at 12 months was not reached, at 74% in the cell group and 69% in the placebo group, with no significant difference (p=0.77). No serious adverse event related to the procedure occurred. The authors said the procedure was safe, but efficacy was not conclusively shown. It is registered as NCT03737461.[6]
- A 2021 trial of mesenchymal precursor cells. This randomized, placebo-controlled study enrolled 100 people with moderate disc degeneration across cell and hyaluronic acid groups, with a saline control. Through 36 months the cell groups had significantly better pain and disability scores than controls at several time points. The authors concluded the injection could be safe, effective and durable.[7]
- A 2025 trial of mesenchymal precursor cells with hyaluronic acid. This larger trial enrolled 404 people over 36 months. Its primary endpoint was not significant for either cell group against control, and none of the secondary endpoints differed significantly in all subjects. The cell group with hyaluronic acid did show significantly less low back pain than control at 12 and 24 months, with stronger effects in people whose pain had lasted less than 68 months.[8]
- A 2017 randomized trial. This study enrolled 24 people with chronic back pain and lumbar disc degeneration. One group received allogeneic bone marrow cells by intradiscal injection and the other a sham infiltration of the back muscles. The cell group improved quickly and significantly on the algofunctional indices, and the authors confirmed feasibility and safety. They reported that the benefit was restricted to a group of responders that included 40% of the cohort. It is registered as NCT01860417.[9]
- DREAM, 2025. This phase IIB trial randomized 52 people with chronic low back pain from moderate-to-advanced multilevel disc degeneration to autologous bone marrow cells or a sham procedure. Forty-six completed six months of follow-up. No major adverse events were reported. The cell group showed significant increases in disc height index and nonsignificant improvements in T2 relaxation times at 3 and 6 months, and modified Pfirrmann grades improved at 3 months but returned to baseline at 6 months. The authors reported no significant clinical advantage over the sham procedure, and they described the approach as safe and promising.[10]
Registered Studies
The registrations below are cited for their design and status only. A phase 2 study of autologous bone marrow mesenchymal stem cells in chronic low back pain from multilevel disc degeneration enrolled 48 workers and is listed as completed. It compared intradiscal injection with sham-treated controls.[11] The registration for the DREAM design lists a phase 2 study of 52 participants with an unknown status.[12] A phase 1 study of autologous adipose-derived mesenchymal stem cells with a hyaluronic acid derivative planned 10 patients, with one year of follow-up, and its status is listed as unknown.[13]
How to Read a Disc Study
- The control. Several trials use a sham procedure,[6][10] and a single-arm study has no comparison group at all.[3]
- The outcome. A primary endpoint can fail while secondary measures move. Read both, and read the endpoint the trial named before it began.
- The heterogeneity. A large I-squared value in a meta-analysis means the studies disagree. Check the reviews above for it.
- The size and follow-up. Published randomized trials range from 24 to 404 people, and some registrations list as few as 10.[8][9][13] Follow-up runs from 6 months to 36 months.[8][10]
Where to Find These Studies
Registered studies are listed publicly on ClinicalTrials.gov. Published results are on PubMed. Every source in this guide is listed under References with its PubMed, DOI and registry links.
For the general service, see stem cell therapy at GIOSTAR. For the joints, read stem cell research and osteoarthritis and stem cell research and the knee.
Further reading: the FDA's consumer page on regenerative medicine therapies, fda.gov (a regulator page; not a numbered reference).
Regulatory Status
Stem cell clinics and stem cell use are arguably subject to FDA oversight, and a 2026 review of biologics regulation says that oversight has been enforced unevenly.[14] Our stem cell therapy is not approved by the FDA.
