Essiac (herbal cancer tea)

A four-herb tea linked to a 1922 patient cancer-cure story; the FTC alleged in 2000 that one seller marketed Essiac Tea for cancer and other diseases, and Essiac products are sold today as over-the-counter dietary supplements.

The National Cancer Institute's own current summary states that no controlled data from human studies suggest Essiac or Flor Essence can be effective in treating cancer patients, and that the FDA has not approved either product for cancer or any other medical condition. In 1978 a Canadian corporation filed a Health Protection Branch preclinical new drug submission and received permission to conduct clinical safety and efficacy studies; authorities withdrew that permission in 1982 after the corporation failed to meet its commitments to control manufacturing consistency, isolate and characterize active substances, and design and execute appropriate clinical trials. A retrospective review of 86 cancer patients who received Essiac under Canada's Emergency Drug Release Program between 1978 and 1982 found no clear evidence of improved survival. A 2006 retrospective cohort of 510 Ontario breast-cancer patients found Essiac did not significantly improve quality of life or mood, and Essiac users scored worse on physical well-being than non-users. A controlled animal study found no significant hepatoprotective, hypoglycemic, or immunomodulatory effect. Most strikingly, a controlled laboratory study found that 1%-8% concentrations of Essiac and the distinct eight-herb Flor-Essence product stimulated human breast cancer cell growth in vitro; in MCF-7 cells, 16% Flor-Essence did not differ significantly from controls and 32% was cytotoxic, and the authors noted that human target-cell concentrations were unknown. Cancer Research UK's 2022-reviewed monograph states there is no evidence to use Essiac as a cancer treatment, while Memorial Sloan Kettering's 2021-updated monograph says Essiac has not been shown to treat or prevent cancer.