Rung Five
Diet and food finder
Unclear

Goji berries

wolfberry; dried berries, juice, tea and extracts. Vegetables & fruit.

Safety: People taking warfarin have had raised clotting-test results (INR) after drinking goji tea, and one man bled after drinking goji wine. Allergic reactions, including anaphylaxis, have been reported, mostly in people with certain food or pollen allergies.
Verdict
UnclearThere isn't enough human evidence to say either way.
How sure
Rung 1 · UnprovenLab or animal data only, or never directly tested in people.

The rung shows how sure the science is, not how big the effect is. How to read these ratings

Cancers affected

None shown in people

What the evidence shows

Despite marketing claims, Memorial Sloan Kettering says goji hasn't been tested in clinical studies for cancer. Its extracts slowed some cancer cells in lab studies. The only human data is one small observational study from 1994, which reported benefits when goji polysaccharides were added to an immune therapy; Memorial Sloan Kettering says well-designed trials are needed.

What to do

Fine as a fruit, but not as a cancer treatment. If you take warfarin or another blood thinner, avoid goji teas, juices, wine and extracts, and ask your doctor before eating the berries.

Sources

Memorial Sloan Kettering About Herbs: lycium (goji), December 2021
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Related

Every food we rated, or follow one cancer step by step: breast cancer, colorectal cancer, lung cancer and prostate cancer.