Common gym supplement could help fight cancer

A supplement long associated with gym-goers and muscle building could have an unexpected role in helping the immune system recognize and attack cancer.

Scientists at the University of California, Los Angeles (UCLA) Health Sciences found that creatine may support key immune cells involved in identifying tumors and activating the body’s cancer-fighting defenses.

The first author of the study, James Elsten-Brown, told Newsweek the findings, based on experiments in mice and human cells, revealed creatine may help certain immune cells work more effectively against cancer.

These cells help switch on the body’s cancer-fighting T cells, and when more creatine was available, both types of immune cells appeared better able to attack tumors.

Creatine’s Surprising Role in Cancer Immunity

An estimated 2.1 million people will be diagnosed with cancer in the U.S. in 2026, according to the National Cancer Institute, including more than 100,000 expected cases of melanoma, the most serious form of skin cancer.

Many modern cancer immunotherapies work by activating killer T cells—immune cells that can identify and destroy cancer. However, only about 20 to 40 percent of patients experience major benefits from these treatments.

The UCLA researchers found that dendritic cells—immune cells that help kick-start the body’s defense against cancer—appear to rely on creatine to work properly.

Dr. Selda Samakoglu, a medical oncologist and chief medical officer at Aveta Biomics, explained the importance of these cells to Newsweek.

“Simply, think of dendritic cells as military intelligence officers. They find the enemy (cancer), collect evidence, travel to headquarters (the lymph node), brief the soldiers (T cells), and direct the attack,” Samakoglu told Newsweek.

“Without these intelligence officers, the immune system may know something is wrong but cannot organize an effective, targeted assault against the tumor.”

In mice, the researchers found that dendritic cells inside tumors had high levels of a protein that helps them absorb creatine. When that protein was removed, the cells became weaker, survived for less time and were less able to activate cancer-fighting T cells. As a result, the T cells were less effective at recognizing and attacking tumors.

Lili Yang, the study’s senior author, a professor of microbiology, immunology and molecular genetics and a member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, said in a statement: “Creatine doesn’t just help the T cells fighting cancer—it also energizes the entire infrastructure supports and guides them. That makes creatine a promising supplement to holistically support the immune response that modern immunotherapies depend on.”

Elsten-Brown told Newsweek: “Our study suggests that this anti-tumor immune infrastructure would see a functional benefit from increased available creatine and promote a tumor immunoenvironment that is more favorable for immunotherapy, but we have yet to see a clinical study in which this is demonstrably the case.”

What the Researchers Found

To investigate how creatine affects the immune system, the researchers analyzed dendritic cells that had entered tumors in mice.

They found that these cells produced much higher levels of a protein called the creatine transporter, which moves creatine into cells. This suggested that dendritic cells may rely on creatine while operating inside the nutrient-poor environment of a tumor.

The team then engineered dendritic cells that could no longer absorb creatine. Without access to the compound, the cells were less active, did not survive as well and were much less effective at preparing T cells to recognize and attack tumors.

When these creatine-deficient dendritic cells were grown with T cells in laboratory experiments, the T cells multiplied less and produced fewer of the signaling molecules needed for a strong anti-cancer response.

The researchers next tested whether increasing creatine levels would have the opposite effect.

Daily creatine injections in mice with melanoma significantly slowed tumor growth. The treatment also increased the number of dendritic cells inside tumors and boosted their activity.

Researchers found that creatine increased levels of ATP, the molecule cells use as their primary source of energy. By increasing these energy stores, creatine helped dendritic cells maintain the inflammatory signaling needed to activate an immune response.

The scientists compared creatine to a rechargeable battery, allowing dendritic cells to store and release energy when needed—even while competing with rapidly growing cancer cells for nutrients.

Potential Applications Beyond Supplements

The researchers also examined the effects of creatine on human immune cells.

In laboratory experiments, creatine enhanced the activation of human dendritic cells and improved their ability to stimulate T cells against a cancer-related target.

The findings suggest creatine could eventually have two potential uses: helping boost immune responses in patients already receiving immunotherapy and improving dendritic cell-based cancer vaccines before they are given to patients.

“The potential we see here is that creatine could be used in two complementary ways: as a supplement to enhance the immune response of patients already receiving immunotherapy, and as a tool to improve the quality of dendritic cell-based vaccines before they’re administered,” said James Elsten-Brown, a co-first author and graduate student in Yang’s lab.

Overall, the results suggest creatine may strengthen the immune system’s anti-cancer defenses by supporting the cells that detect cancer and launch the body’s response.

“Understanding how to metabolically support dendritic cells is about supporting the entire anti-tumor response, not just the killer T cells at the end of it,” said Elliot Kang, a co-first author of the study and former undergraduate student researcher in Yang’s lab.

Important Limitation

Despite the promising findings, researchers stressed that the study is still in its early stages.

The work was conducted in mice and human cells grown in the laboratory, not in cancer patients. As a result, the findings do not show that taking creatine supplements improves cancer treatment outcomes in people.

Elsten-Brown told Newsweek: “There is not sufficient clinical data to definitively say that creatine supplementation will increase anti-tumor activity in human patients as would be suggested by our pre-clinical models.

“There are a wide variety of factors that can influence how the favorable bioenergetics we see in our dendritic cells grown in a dish may or may not translate into a patient taking creatine, even simply whether orally administered creatine would be sufficiently available to immune cells in and around the tumor immunoenvironment.”

Further research, including human studies, will be needed before doctors can determine whether creatine has a role in cancer care.

Contact Newsweek editors on this story: Kara Dolman and Emma Lee-Sang