Creatine, the over-the-counter supplement used by millions of athletes and gym-goers to build muscle and improve performance, may also help the immune system fight cancer, according to new research from UCLA published in the journal iScience.
The study, highlighted by ScienceDaily on July 8, 2026, found that creatine fuels a critical class of immune cells called dendritic cells — specialized sentinels that detect tumor fragments and direct the body's cancer-killing T cells to attack. When creatine was supplied to mice with melanoma, tumor growth slowed, and the number of dendritic cells inside tumors increased. In human dendritic cells tested in a laboratory dish, creatine also enhanced activation and improved the cells' ability to prime T cells for an immune attack.
The researchers say the finding could eventually help make cancer immunotherapy work for more patients — but it has not yet been tested in people.
Why This Matters
Most approved cancer immunotherapies work by unleashing or strengthening killer T cells — the immune system's primary weapon against tumors. But only about 20% to 40% of cancer patients respond to current immunotherapy treatments, a limitation researchers have struggled to overcome.
One reason is that dendritic cells — which must first detect the tumor, capture fragments of it, and then activate T cells to attack — are often poorly equipped inside the nutrient-starved environment of a tumor. Without enough energy to function, dendritic cells cannot effectively coordinate the immune response that immunotherapy drugs are designed to amplify.
The UCLA study suggests creatine may be able to address that energy gap directly. In the tumor microenvironment, UCLA researchers found, dendritic cells significantly upregulate their creatine transporter — essentially ramping up their intake of creatine to meet the energy demands of mounting an immune response. Supplying additional creatine enhanced their survival, their activation, and their ability to prime T cells.
This builds on prior work from the same UCLA lab, led by Professor Lili Yang, which found that creatine also boosts killer T cells directly. The new study adds a second layer to the picture: creatine may support both the T cells doing the attacking and the dendritic cells coordinating the attack.
What We Know So Far
The study, led by Elliot Kang, Lili Yang, and colleagues at UCLA's Department of Microbiology, Immunology and Molecular Genetics and the Parker Institute for Cancer Immunotherapy, was published in iScience (DOI: 10.1016/j.isci.2026.115436) and covered by the UCLA Health newsroom.
Key findings confirmed in the study:
- Dendritic cells inside tumors strongly upregulate the creatine transporter (CrT), indicating they actively seek out creatine as an energy source in the tumor microenvironment
- Dendritic cells engineered to lack the creatine transporter entirely showed impaired survival, reduced activation, and a weaker ability to prime T cells
- Supplementing mice with melanoma with 10.5 mg/day of creatine for 13 days suppressed tumor growth and increased the number of dendritic cells within each tumor
- Human dendritic cells from healthy donors, when treated with creatine in lab dishes, showed enhanced activation markers and a greater ability to activate T cells
A patent application covering the potential therapeutic strategy has been filed by the UCLA Technology Development Group on behalf of the Regents of the University of California — an indication that UCLA sees commercial potential in the approach.
Where the Potential Impact Is Highest
If creatine supplementation is ultimately found to enhance immunotherapy responses in human clinical trials, the patients most likely to benefit would be those who currently do not respond to checkpoint blockade and other immunotherapy drugs — the roughly 60% to 80% of patients for whom existing immunotherapies do not work.
Melanoma was the cancer model used in this study, and melanoma is one of the cancers for which immunotherapy has already shown meaningful clinical success. Whether creatine's effects on dendritic cells extend to other cancer types — and how they might interact with existing immunotherapy drugs — are open questions that the research team has identified as priorities for future investigation.
Researchers at UCLA said their next goal is to work with oncologists to design clinical trials that test whether creatine supplementation actually improves outcomes for people undergoing immunotherapy. No trial is currently registered or underway as of the date of this publication.
What Researchers Say
"Creatine is widely known as a sports supplement, but new UCLA research suggests it could also help the immune system fight cancer," the UCLA Health newsroom stated in its description of the study.
The study's senior author, Professor Lili Yang, has framed the finding as an extension of her lab's broader interest in the metabolic support of anti-tumor immune cells. In the resource-depleted environment inside a tumor, immune cells must compete with cancer cells for nutrients. Creatine, which functions as a rapid energy storage molecule — converting into phosphocreatine to regenerate ATP — appears to give dendritic cells the metabolic advantage they need to survive, activate, and function effectively inside that hostile environment.
The finding also points toward a potential application in dendritic cell-based cancer vaccines, where creatine might be used to improve the function of dendritic cells before they are reinfused into a patient — an approach that would not require patients to take the supplement directly.
What the Evidence Shows — and What It Does Not
This research was conducted in a single mouse melanoma model (B16-OVA) and in human dendritic cells isolated from healthy adult donors and tested in laboratory dishes. The study authors specifically noted this as a key limitation: results from one mouse model and from cell culture experiments do not automatically translate to clinical benefit in human cancer patients with different tumor types, stages, or immunological profiles.
No cancer patients were enrolled in this study. No clinical trial has been registered or announced. The FDA has not evaluated or approved any use of creatine as a cancer treatment.
The finding that creatine increases dendritic cell activation is biologically meaningful and consistent with what is known about creatine's role in energy metabolism — but it is an early-stage discovery.
MedicalDaily Evidence Check
- Study type: Preclinical study in mouse melanoma model + human dendritic cell laboratory experiments
- Published: March 21, 2026, iScience (DOI: 10.1016/j.isci.2026.115436); ScienceDaily highlighted July 8, 2026
- Institution: UCLA Department of Microbiology, Immunology and Molecular Genetics; Parker Institute for Cancer Immunotherapy
- What it found: Creatine fuels dendritic cells' survival and activation; creatine supplementation suppressed tumor growth in mice; human dendritic cells showed enhanced T cell activation after creatine treatment
- What it did not find: Clinical benefit in human cancer patients; no human trials have been conducted
- Key limitation: Single mouse model used; human cell experiments conducted in lab dishes; clinical translation uncertain
- What readers should know: Creatine supplementation is not a cancer treatment; do not alter cancer treatment plans based on this finding; consult an oncologist before combining supplements with any cancer therapy
Who Could Benefit Most?
If clinical trials eventually confirm that creatine enhances immunotherapy response in humans, the populations most likely to benefit are:
- Cancer patients who do not currently respond to checkpoint inhibitor immunotherapy (pembrolizumab, nivolumab, and others)
- Patients with melanoma, where dendritic cell-mediated immunity has been studied most extensively
- Potentially, patients enrolled in dendritic cell vaccine programs, where ex vivo creatine enhancement of dendritic cells before reinfusion might improve vaccine potency
For healthy readers who already take creatine as a supplement: while this study suggests a possible secondary immune benefit, it does not confirm that current supplementation doses in healthy people produce meaningful immune effects. Clinical dosing for potential cancer applications would need to be determined separately.
What You Can Do Now
For most readers, this research does not require any immediate action. For patients currently undergoing cancer treatment:
- Do not start, stop, or change any supplement without consulting your oncologist. Creatine and many other supplements can interact with cancer drugs, affect kidney function under chemotherapy, or influence tumor microenvironment in ways not yet understood.
- Ask your oncologist about immunotherapy eligibility. If you have a cancer type where immunotherapy is used — including melanoma — ask whether you are a candidate and what factors might affect response.
- Watch for clinical trial announcements. The UCLA team has stated its next goal is clinical trial design. Check Clinicaltrials.gov periodically for any registered trials combining creatine and immunotherapy.
- Stay skeptical of early research claims. The supplement industry has a long history of overstating preliminary findings. This is promising preclinical research, not a proven cancer treatment.
Cost and Access: What Patients Should Know
Creatine monohydrate is one of the most affordable and widely available supplements on the market, typically costing between $0.10 and $0.25 per serving. It is sold in powder and capsule form at pharmacies, grocery stores, and online retailers without a prescription.
However, buying creatine off the shelf for cancer-related purposes is explicitly not recommended based on this research alone. The doses, timing, formulations, and clinical contexts needed to achieve any anti-cancer benefit in humans are entirely uncharacterized. Any future use of creatine in a cancer treatment context would occur within a clinical trial under medical supervision.
What Happens Next
The UCLA research team's stated next step is designing clinical trials in collaboration with oncologists to determine whether creatine supplementation improves outcomes for patients receiving immunotherapy. Designing, funding, and conducting such a trial is a multi-year process. No estimated start date has been announced.
The Parker Institute for Cancer Immunotherapy, which is affiliated with this research, has a track record of advancing cancer immunology discoveries into clinical trials across multiple cancer types. MedicalDaily will monitor for trial registration and update this story when relevant developments emerge.
The Bottom Line
A UCLA study found that creatine — the gym supplement widely used for muscle building — also fuels dendritic cells, the immune system's tumor-detection sentinels. In mice with melanoma, creatine supplementation slowed tumor growth. In human dendritic cells, it enhanced immune activation. The research is early-stage and has not been tested in human cancer patients. It does not mean creatine treats or prevents cancer. But it adds a biologically credible new direction to the search for ways to extend immunotherapy's reach to patients who do not currently respond — and it comes from a well-regarded lab with prior work supporting the same mechanism.
