Don’t stop proper treatment to try folk remedies or supplements
For cancers that can be cured, the risk of death for people who only use alternative therapies and do not receive conventional treatment is 2.5 times that of those who receive conventional treatment. People who use complementary therapies along with treatment are more likely to refuse surgery, chemotherapy, and radiation, and this is where the excess deaths come from. Some herbs (such as Hypericum perforatum) can also weaken the effect of anti-rejection drugs and anticoagulants. If you want to take them, ask your doctor first.
No cost at all;
Two studies from US cancer registries examined nonmetastatic, potentially treatable breast, prostate, lung and…
No cost at all; you even save money you’d otherwise spend on supplements. It takes no extra time. The hard part is resisting repeated pressure from others to give it a try.
Two studies from US cancer registries examined nonmetastatic, potentially treatable breast, prostate, lung and colorectal cancers. The first examined people using alternative therapy alone, refusing surgery, chemotherapy, radiotherapy and hormone therapy. Compared with matched conventional-treatment patients, their risk of death was 2.5 times as high (hazard ratio HR 2.50, 95% CI 1.88–3.27, about 150% higher). For breast cancer it was 5.68 times (3.22–10.04), lung cancer 2.17 times (1.42–3.32) and colorectal cancer 4.57 times (1.66–12.61). The second examined complementary therapy alongside conventional treatment. Refusal rates were 7.0% versus 0.1% for surgery, 34.1% versus 3.2% for chemotherapy, 53.0% versus 2.3% for radiotherapy, and 33.7% versus 2.8% for hormone therapy. Five-year survival was 82.2% versus 86.6%; death risk was 2.08 times as high (hazard ratio HR 2.08, 1.50–2.90, about twice as high). After accounting for delay and refusal, complementary therapy itself showed no clear association with death (hazard ratio HR 1.39, 0.83–2.33). The authors concluded that excess deaths came from refusing conventional treatment. China's State Administration for Market Regulation requires health-food labels to state that health foods are not medicines and cannot replace medicines for treating disease. The US National Center for Complementary and Integrative Health (NCCIH) states that St John's wort reduces the effects of many medicines, including cyclosporine for transplant rejection prevention and the anticoagulant warfarin.
Johnson SB, Park HS, Gross CP, Yu JB (2018). Use of Alternative Medicine for Cancer and Its Impact on Survival. Journal of the National Cancer Institute, 110(1), 121-124. https://doi.org/10.1093/jnci/djx145；Johnson SB, Park HS, Gross CP, Yu JB (2018). Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers. JAMA Oncology, 4(10), 1375-1381. https://doi.org/10.1001/jamaoncol.2018.2487；国家市场监督管理总局 (2019). 市场监管总局就《保健食品标注警示用语指南》和《保健食品原料目录与保健功能目录管理办法》有关情况举办专题新闻发布会. https://www.samr.gov.cn/tssps/sjdt/tpxw/art/2023/art_4b658b824b1b4b0ba57c09a56cc93aad.html；National Center for Complementary and Integrative Health (2025). St. John's Wort. https://www.nccih.nih.gov/health/st-johns-wort
Open source linkRated only B. Both studies concerned cancer alone and followed registry data without randomized groups; people choosing alternatives may also differ in other ways. For stopping medicines for hypertension or diabetes, see item 1 (take the prescribed course). Tell your treating doctor before trying supplements. For whether health products are worth buying, see Section 6, item 10 (health products, herbal pastes and tonics).