Parkinson’s Stem Cell Therapy: Who Is It For, and How Is It Done?

Is There a Treatment for Parkinson's?

There is not yet a treatment that eliminates Parkinson's completely; but drugs, surgical methods and rehabilitation can reduce symptoms (WHO). The backbone of treatment is levodopa and the other dopamine drugs. Exercise and physical therapy complement them, and in the periods when the effect of the drug fluctuates, advanced options such as deep brain stimulation come into play (Armstrong and Okun, 2020).

You have tried many things and read many things before coming to this page; we know. So let us say it at the outset: stem cell treatment does not replace your drugs, your follow-up with your neurologist or deep brain stimulation; in patients who are found suitable, it is planned together with them.

Has a treatment for Parkinson's been found? New developments

A definitive solution has not yet been found, but truly important developments have taken place in the last two years. Behind news stories headed "A treatment for Parkinson's has been found", there are usually these three developments:

• New drug (tavapadon): The FDA approved this tablet, taken once a day, in September 2026 (FDA, 2026). In a Phase 3 study done in the early stage, the symptom score in 304 people improved 9.1 points more than with placebo; the rate of stopping because of side effects was 24% and 4% (Fernandez et al., 2026). It is a drug that eases symptoms; it is not claimed to cure the disease.
• Dopamine cells of iPS origin: In March 2026, Japan gave conditional and time-limited approval to a product called raguneprocel. It is based on a study of 7 people; the movement score improved in 4 of the 6 patients evaluated, and the average change at month 24 was 9.5 points (20.4%) (Sawamoto et al., 2025). Its use will be monitored for 7 years (Parkinson's UK, 2026).
• Dopamine cells of embryonic origin: In a Phase 1 study of 12 people done with bemdaneprocel, the movement score in the high-dose group improved by an average of 23 points at month 18 (Tabar et al., 2025). This study had no control group; the product is now being tested in a Phase 3 study in which it is compared with sham surgery (NCT06944522).

These methods, in which dopamine cells are placed in the brain by surgery, are not the method Gencell uses; we explain the difference in a table below.

What Is Parkinson's Disease?

Parkinson's is a neurodegenerative disease that progresses with the gradual loss of the nerve cells that produce dopamine in a region of the brain called the substantia nigra. The buildup of a protein called alpha-synuclein in these cells is one of the distinctive features of the disease. The four main signs are shaking (tremor), slowing of movement (bradykinesia), muscle stiffness, and difficulty with balance and walking. Non-motor symptoms such as sleep problems, depression, constipation and difficulty thinking can also be seen; one of these is Parkinson's disease dementia. More than 8.5 million people worldwide are estimated to live with this disease (WHO).

Parkinsonism is the general name for the conditions that lead to similar movement problems, and Parkinson's disease is the most common of them (Armstrong and Okun, 2020).

Which Methods Are Used to Treat Parkinson's?

Parkinson's treatment is planned by a neurologist according to the patient's symptoms and the stage of the disease. There is no single "best" method. In most patients, some of these methods are used together.

Sources: Armstrong and Okun, 2020, WHO, Katzenschlager et al., 2018.

On the question "What is best for Parkinson's?", we want to mention exercise separately, because it is supported by research and within your reach. A Cochrane review that combined 154 randomized studies shows that most types of exercise, including dance, walking and balance training, bring benefit in movement symptoms and quality of life (Ernst et al., 2024).

Does Parkinson's Get Better Completely, Has Anyone Recovered?

Medicine today does not describe a complete recovery from Parkinson's; but the course is not the same in everyone, and with the right treatment the symptoms can be eased. In about half of patients, the symptoms run a mild course, the response to drugs is good and the disease progresses slowly (Armstrong and Okun, 2020).

It is very natural to feel hopeful when you read stories such as "I got rid of Parkinson's". In these accounts, a decrease in symptoms and the disease going away are often confused with each other. The diagnosis is not always certain from the start either: in studies confirmed by autopsy, the accuracy of the clinical diagnosis is about 81% (Rizzo et al., 2016). This is why what one person goes through is not a prediction for someone else.

As for the question whether Parkinson's can be stopped, there is not yet a treatment that has been shown to stop the disease. Slowing progression is today the most important goal of research, and also one of the goals of stem cell treatment. The developments we listed above and the studies below show that this field is moving forward quickly.

How Does Stem Cell Therapy Work in Parkinson's?

With mesenchymal stem cells, the goal is for the cells to reduce inflammation in the brain (neuroinflammation) and to support nerve cells through the factors they release. This effect is called the paracrine effect. In animal studies, these cells reduced the activity of inflammatory cells and supported the survival of dopamine cells. Because 80 to 90% of the cells given through a vein are held in the lungs, most of the effect is thought to come from these secretions (Schiess et al., 2025).

The first signs from humans point the same way: in a Phase 1 study with five patients, the inflammation markers in the spinal fluid of the patients who were sampled fell in the days after the procedure, and the dopamine level rose (Zhuo et al., 2024).

The difference between mesenchymal cells and dopamine cell transplantation

Although the news often describes them as a single "stem cell therapy", these are two separate approaches. The method we use is the mesenchymal cell approach.

Why are donor cells used?

In Parkinson's, we do not use the patient's own cells; we prefer cells taken from healthy donors (allogeneic), that is, mesenchymal stem cells (WJ-MSC) obtained from umbilical cord tissue (Wharton's jelly). This is because the capacity of adult mesenchymal cells to multiply decreases with age (Zhou et al., 2008), while umbilical cord tissue cells have a structure that stimulates the immune system less (Weiss et al., 2008).

How are the cells prepared?

We do not produce the cells ourselves; we work with Turkey's leading large stem cell producers under state supervision. The GMP (Good Manufacturing Practice) standard, donor screening and the quality control tests are carried out at the producers we work with.

What Do Studies of Parkinson's Stem Cell Therapy Show?

Published studies show that the procedure can be carried out safely, and in some studies encouraging improvements in movement symptoms are reported; the results vary from study to study. In the table, UPDRS is the scale that scores Parkinson's symptoms, and a fall in the score means that the symptoms have eased. We write the results as they are, so that you can make the decision with the most accurate information.

The most encouraging signal comes from the Schiess study, in which three infusions were given. This group improved 2.3 points more than placebo, and the researchers calculated the probability of a real difference as 87.8%. At week 88, the proportion of those who reached a large improvement of at least 11 points was 42 percentage points higher in this group than with placebo, and the quality of life score also differed in its favor. In the same study, however, the group that received two infusions fell behind placebo. The authors also list the difference between cell batches among the possible reasons.

The 14.6-point improvement in the placebo group is an important piece of information: in Parkinson's, expectation itself can also ease symptoms for a while. This is why studies with no control group and changes seen in a short time need to be read with care. The Vij study found no difference from placebo. In this small study, the scores of both groups were preserved, and the authors state that the study was not designed with the power to prove efficacy.

The umbilical cord MSC data come from open-label controlled studies and small studies. In our search, we did not find a double-blind, placebo-controlled Parkinson's study done with cord tissue cells. A 2026 review that brings together stem cell studies in neurological diseases also evaluates the procedure in Parkinson's as being at an early stage, favorable in terms of safety and with clinical evidence that is still limited (Jamali et al., 2026). The FDA has not approved any stem cell product for Parkinson's (FDA). The field is developing quickly, and we update this table as new studies come out.

No one can guarantee you a full recovery. Do not trust anyone who says they can.

Who Is Parkinson's Stem Cell Therapy For?

Parkinson's stem cell therapy is evaluated in patients diagnosed with Parkinson's, after their file has been reviewed by our Scientific Council. The patient's current clinical condition, the neurology report, the response to drugs and brain imaging determine the decision together. We explain the reason to our patients who are not found suitable.

Which documents are needed for the evaluation?

You can make an evaluation request by sending the documents through the contact form.

How Is Parkinson's Stem Cell Therapy Done?

Parkinson's stem cell therapy proceeds in four steps, from the review of the documents to the procedure and follow-up.

Step 1: Preliminary evaluation

The documents above and the video are sent to us, and a medical file is opened in your name. You do not need to come to the center at this stage.

Step 2: Evaluation by our Scientific Council

Physicians from different specialties on our Scientific Council review the file. If it is not found suitable, we share the reason with you. If it is found suitable, we hold an online video meeting with you and talk about the course of the disease, what can be expected from the treatment and the process.

Step 3: Personalized protocol and Ministry approval

The total number of cells, the route of administration and the number of sessions are set according to your condition; the cost also becomes clear according to this protocol. For our patients who are Turkish citizens, the consents are completed, the file is sent to the Ministry of Health for a stem cell treatment permit, and the schedule is finalized after the Ministry's approval. For our patients who are not Turkish citizens, the Ministry of Health's patient-by-patient approval process is not required. Once the medical history forms are filled in and informed consent is obtained, the schedule is planned.

Step 4: The procedure and follow-up

The cells are given through a vein or by the intrathecal procedure into the spinal fluid through the lower back; our Scientific Council decides which route will be chosen. Before the procedure, specialists in the relevant fields carry out the examination and the final evaluation, and the blood tests are checked. The procedure is done in a hospital setting and under observation.

What Should You Expect After the Treatment?

The change after the treatment can differ from patient to patient; in a treatment started with a realistic goal, we follow every step gained together with you. Before the treatment begins, we also talk openly with you about the possibility of no benefit at all. Levodopa and your other drugs continue during this process, and the decision on the dose belongs to your neurologist.

How is the change evaluated?

It is soundest to follow the change together with your neurologist, with the same scales: the UPDRS score, movements in the periods with and without medication, daily living and quality of life. This is why we attach importance to the measurement before the treatment. In a published study, the change in the group that received three infusions was seen in the first 9 weeks (Schiess et al., 2025), but because the placebo effect is also strong in the first period, we recommend that you make the main evaluation over a longer follow-up.

Is Parkinson's Stem Cell Therapy Safe?

In published studies, most side effects were mild and temporary; still, the procedure is not risk-free and requires a physician's supervision. In a meta-analysis of 71 records that combined cell therapies in neurodegenerative diseases, the frequency of serious side effects was found to be 0.03 and did not differ from the control groups (Van den Bos et al., 2022). The details in the Parkinson's studies are as follows:

• Through a vein: In the study of 45 people, 10 mild, temporary events such as fatigue, flu-like complaints, headache and vomiting were reported, and no severe event was seen (Schiess et al., 2025). In the study of 24 people, the only serious event was assessed as unrelated to the product (Vij et al., 2026).
• Intrathecal procedure: No serious side effect was seen in the Parkinson's study of 5 people (Zhuo et al., 2024). In an intrathecal study of 5 people done in autism with cord tissue cells, temporary fever was seen in all of them and vomiting in four, and the complaints passed in a short time (Khodadoust et al., 2026). We talk about the risk of the procedure in detail in the meeting.
• Dopamine cell transplantation (a different method): It carries the risks of surgery and of immunosuppressive treatment. In one study, involuntary movements increased (Sawamoto et al., 2025); in another study of 8 people, one patient died of a lung infection, and the death was attributed not to the product but to the immunosuppressive treatment (Paul et al., 2026).

Long-term safety data are limited. Our physician talks with you in the evaluation meeting about the risk of side effects, on the basis of your file and the route of administration to be chosen.

Which Hospitals Offer Parkinson's Stem Cell Therapy, and How Is It Done?

Parkinson's stem cell therapy is done at contracted, approved private medical centers in Istanbul, in a hospital setting and by teams of specialist physicians. It is not done in public hospitals. Physicians from different specialties on our Scientific Council review your file, and your follow-up continues with your neurologist. The facilities we work with comply with the 2025 Regulation on Products Obtained from Human Tissues and Cells, and for Turkish citizens a Ministry of Health approval is obtained for every procedure. If you live in another city, the preliminary evaluation can be done remotely. You need to come to Istanbul for the procedure.

What Determines the Price of Parkinson's Stem Cell Therapy?

The price of Parkinson's stem cell therapy becomes clear once our Scientific Council sets the personalized protocol; this is why we do not give a figure without seeing the file. The main factors that determine the price are the number of cells to be given, the route of administration and the number of sessions. SGK (Turkey's public health insurance) and private health insurance do not cover stem cell therapies. Whichever center you talk to, we recommend that you ask for the quote in writing, item by item.

You can make an evaluation request by sending your file through the contact form.

Which Questions Should You Ask Before Deciding?

Our patients and their relatives can come across very different claims when making this decision. The International Society for Stem Cell Research also recommends asking questions of this kind before deciding (ISSCR, 2024). We recommend that you ask every center you talk to, including us, the following:

• Which cell will be used, which producer does it come from, and how is quality control done?
• How will the Ministry of Health approval process work?
• Who will do the procedure, and how will they work with my neurologist?
• What will happen to my drugs, which side effects can be seen, and whom will I contact afterwards?
• Is this procedure part of a registered clinical trial?
• With which scale and when will the change be evaluated?
• What happens if there is no benefit at all?
• What is included in the price?

You can ask for our Scientific Council's evaluation by sending your file through the contact form.

Frequently Asked Questions

Is stem cell therapy good for Parkinson's?

It is not possible to say this for every patient. In an analysis that combined controlled studies, symptom scores fell in favor of stem cells, in a placebo-controlled study of 45 people the group that received three infusions improved slightly more than placebo, and in another small study no difference was found. It is also possible that no benefit is seen.

Does stem cell therapy replace drugs or deep brain stimulation?

No, it does not replace them. Levodopa, the other drugs, deep brain stimulation and follow-up with a neurologist continue. Stem cell treatment is planned alongside them in patients who are found suitable. Do not stop or reduce your drugs without consulting your physician.

How many years does the effect of stem cell therapy last?

We cannot give a definite duration for this. In the meta-analysis, it was reported that the effect could last at least 12 months, while the period after 12 months was not followed sufficiently. In the placebo-controlled study of 45 people, the difference in the group that received three infusions was still present at week 88.

Has a Parkinson's vaccine come out?

There is not yet an approved Parkinson's vaccine, but research is continuing. PD01A, which targets alpha-synuclein, was found safe in a Phase 1 study of 24 patients and created an antibody response (Volc et al., 2020). UB-312 also created an antibody response in a Phase 1 study of 20 patients, and no difference was found on clinical scales (Eijsvogel et al., 2024). Further studies are needed to show its benefit.

What can be done so that Parkinson's does not progress?

There is not yet a treatment that has been shown to stop progression; still, you have strong tools in your hands. Regular exercise improves movement symptoms and quality of life, and regular follow-up with a neurologist makes it possible to adjust treatment as needed. Research aimed at slowing it is also continuing.

What happens if Parkinson's is not treated?

Symptoms can increase over time, and daily tasks can become harder. But the course varies greatly from person to person. Some forms progress fast and others slowly. It is not right to predict a time span for individual patients. Because treatment eases symptoms and makes daily life easier, early planning with a neurologist is important.

Is the treatment covered by SGK (Turkey's public health insurance) or private insurance?

No. Neither SGK nor private health insurance covers stem cell therapies. The cost becomes clear once our Scientific Council sets the protocol, and you are told what it is.

Is it done in public hospitals?

No. Parkinson's stem cell treatments are not done in public hospitals. We plan them at contracted, approved private medical centers in Istanbul.

References

1. Armstrong MJ, Okun MS. Diagnosis and Treatment of Parkinson Disease: A Review. JAMA, 2020;323(6):548-560. https://doi.org/10.1001/jama.2019.22360
2. World Health Organization. Parkinson disease (fact sheet). https://www.who.int/news-room/fact-sheets/detail/parkinson-disease
3. Eijsvogel P, Misra P et al. Target engagement and immunogenicity of an active immunotherapeutic targeting pathological α-synuclein: a phase 1 placebo-controlled trial. Nat Med, 2024;30(9):2631-2640. https://doi.org/10.1038/s41591-024-03101-8
4. Ernst M, Folkerts AK, Gollan R et al. Physical exercise for people with Parkinson's disease: a systematic review and network meta-analysis. Cochrane Database Syst Rev, 2024;4:CD013856. https://doi.org/10.1002/14651858.CD013856.pub3
5. FDA. Approved Drug Products (Orange Book), September 2026 list, tavapadon. https://www.fda.gov/media/71502/download
6. FDA. Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes, 2020. https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/consumer-alert-regenerative-medicine-products-including-stem-cells-and-exosomes
7. Fernandez HH, Bhatia P, Cloud L et al. Safety, tolerability, and efficacy of flexible-dose tavapadon for Parkinson's disease (TEMPO-2). Lancet Neurol, 2026;25(8):721-730. https://doi.org/10.1016/S1474-4422(26)00215-2
8. International Society for Stem Cell Research. Patient Handbook on Stem Cell Therapies, February 2024. https://www.isscr.org/s/ISSCR_PatientHandbook_v12_Feb2024_Redesign_v4b.pdf
9. Jamali et al. Advances in the clinical application of mesenchymal stem cells for neurological disorders. Stem Cell Res Ther, 2026;17:285. https://doi.org/10.1186/s13287-026-05229-5
10. Katzenschlager R, Poewe W, Rascol O et al. Apomorphine subcutaneous infusion in patients with Parkinson's disease with persistent motor fluctuations (TOLEDO). Lancet Neurol, 2018;17(9):749-759. https://doi.org/10.1016/S1474-4422(18)30239-4
11. Khodadoust E et al. Three repeated intrathecal injections of allogenic umbilical cord-derived mesenchymal stromal cells in autism spectrum disorder: a Phase I clinical trial. Stem Cell Res Ther, 2026;17(1). https://doi.org/10.1186/s13287-026-05122-1
12. NCT06944522. A Study to Investigate the Efficacy and Safety of Bemdaneprocel in Adults Who Have Parkinson's Disease. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT06944522
13. Parkinson's UK. Stem cell treatment for Parkinson's approved in Japan, 25 March 2026. https://www.parkinsons.org.uk/news/2026/stem-cell-treatment-for-parkinsons-approved-japan
14. Paul G, Bjartmarz H et al. Human embryonic stem cell-derived dopaminergic cells for Parkinson's disease: a phase 1/2 open-label trial. Nat Med, 2026;32(9):3449-3457. https://doi.org/10.1038/s41591-026-04525-0
15. Rizzo G, Copetti M, Arcuti S et al. Accuracy of clinical diagnosis of Parkinson disease: A systematic review and meta-analysis. Neurology, 2016;86(6):566-576. https://doi.org/10.1212/WNL.0000000000002350
16. Sawamoto N, Doi D et al. Phase I/II trial of iPS-cell-derived dopaminergic cells for Parkinson's disease. Nature, 2025;641(8064):971-977. https://doi.org/10.1038/s41586-025-08700-0
17. Schiess MC, Suescun J, Martinez-Lemus JD et al. Allogeneic Bone Marrow-Derived Mesenchymal Stem Cells for Parkinson's Disease: A Randomized Trial. Mov Disord, 2025;40(12):2688-2699. https://doi.org/10.1002/mds.70028
18. Tabar V, Sarva H et al. Phase I trial of hES cell-derived dopaminergic neurons for Parkinson's disease. Nature, 2025;641(8064):978-983. https://doi.org/10.1038/s41586-025-08845-y
19. Van den Bos J, El Ouaamari Y et al. Are Cell-Based Therapies Safe and Effective in the Treatment of Neurodegenerative Diseases? A Systematic Review with Meta-Analysis. Biomolecules, 2022;12(2):340. https://doi.org/10.3390/biom12020340
20. Vij R, Kim H, Park H et al. Evaluation of Multiple Intravenous Infusions of Autologous Adipose-Derived Mesenchymal Stem Cells in Parkinson's Disease: A Randomized, Double-Blind Clinical Trial. Parkinsons Dis, 2026:9934417. https://doi.org/10.1155/padi/9934417
21. Volc D, Poewe W, Kutzelnigg A et al. Safety and immunogenicity of the α-synuclein active immunotherapeutic PD01A in patients with Parkinson's disease. Lancet Neurol, 2020;19(7):591-600. https://doi.org/10.1016/S1474-4422(20)30136-8
22. Weiss ML, Anderson C, Medicetty S et al. Immune properties of human umbilical cord Wharton's jelly-derived cells. Stem Cells, 2008;26(11):2865-2874. https://doi.org/10.1634/stemcells.2007-1028
23. Zhao J, Qu K, Jia S et al. Efficacy and efficacy-influencing factors of stem cell transplantation on patients with Parkinson's disease: a systematic review and meta-analysis. Front Neurol, 2024;15:1329343. https://doi.org/10.3389/fneur.2024.1329343
24. Zhou S, Greenberger JS, Epperly MW et al. Age-related intrinsic changes in human bone-marrow-derived mesenchymal stem cells and their differentiation to osteoblasts. Aging Cell, 2008;7(3):335-343. https://doi.org/10.1111/j.1474-9726.2008.00377.x
25. Zhuo Y, Li WS, Lu W et al. TGF-β1 mediates hypoxia-preconditioned olfactory mucosa mesenchymal stem cells improved neural functional recovery in Parkinson's disease models and patients. Mil Med Res, 2024;11(1):48. https://doi.org/10.1186/s40779-024-00550-7
26. Regulation on Products Obtained from Human Tissues and Cells and the Centers Related to These Products (İnsan Doku ve Hücrelerinden Elde Edilen Ürünler ve Bu Ürünler ile İlgili Merkezler Hakkında Yönetmelik). Official Gazette (Resmî Gazete), 4 September 2025, No. 33007.