Last reviewed June 12, 2026 · AI-assisted, human-reviewed
Overview
Natural compounds with the strongest preclinical and emerging clinical evidence for adjunctive cancer support — never a replacement for oncologist-directed care. Many of these interact with chemotherapy and radiation; always coordinate with your oncology team before adding anything.
Cancer is a complex group of diseases characterized by the uncontrolled growth and spread of abnormal cells. It can originate in virtually any organ or tissue and affects millions worldwide, regardless of age, gender, or background. Individuals often seek support for managing symptoms, improving quality of life during treatment, and exploring strategies that may complement conventional therapies. The journey with cancer can involve various physical and emotional challenges.
Why it may help Cancer (Adjunctive Support): Studied (mostly as nabiximols, a THC:CBD spray) for cancer pain refractory to opioids; preliminary evidence for chemotherapy-related anxiety and sleep disruption.
High-dose CBD can inhibit CYP3A4 and CYP2C19 — relevant for many chemotherapies and supportive medications. Always disclose use to the oncology team.
Why it may help Cancer (Adjunctive Support): Vitamin C has been studied for its potential role in cancer as an adjunctive therapy due to several proposed mechanisms. It may act as an antioxidant, helping to reduce oxidative stress, and is also an essential cofactor for collagen synthesis. Preclinical research suggests that very high doses administered intravenously may exert a pro-oxidant effect, selectively targeting cancer cells.
Individuals with certain conditions, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, should avoid high-dose intravenous vitamin C due to the risk of hemolysis. Kidney function should be monitored, especially with high-dose regimens, given concerns about oxalate formation and kidney stones in susceptible individuals. Potential interactions with chemotherapy agents are a subject of ongoing research and require careful medical supervision.
Why it may help Cancer (Adjunctive Support): Multiple RCTs and meta-analyses show oral THC (dronabinol) and nabilone reduce chemotherapy-induced nausea and vomiting refractory to standard antiemetics, and improve appetite in advanced cancer.
Always coordinate with the oncology team. THC interacts with opioids, benzodiazepines, and CYP3A4-metabolized chemotherapies. Start low, go slow.
Why it may help Cancer (Adjunctive Support): Reishi mushroom contains compounds such as beta-glucans and triterpenes that have been studied for their potential to modulate immune activity, including natural killer (NK) cells and macrophages, which play a role in the body's defense mechanisms. In preclinical models, components of Reishi mushroom appear to inhibit tumor angiogenesis, suggesting a possible mechanism for adjunctive support in cancer care.
Individuals undergoing chemotherapy or radiation should exercise caution due to potential interactions or additive effects. Reishi may have anticoagulant properties; therefore, it should be used with caution in individuals using blood-thinning medications or prior to surgery. It may lower blood pressure, which could be a consideration for patients already experiencing low blood pressure.
Why it may help Cancer (Adjunctive Support): Turmeric, particularly its active compound curcumin, has been studied for its potential to modulate inflammatory pathways such as NF-kB and COX-2. These pathways are often dysregulated in various cancers, suggesting a potential role for turmeric in adjunctive support by influencing these biological processes.
Individuals undergoing chemotherapy or radiation should exercise caution due to potential interactions. High doses may cause gastrointestinal upset. Turmeric may have antiplatelet effects, which could be a consideration for patients at risk of bleeding or those on anticoagulant medications; consultation with a healthcare provider is important.
Why it may help Cancer (Adjunctive Support): In vitro studies suggest that certain compounds found in soursop, particularly Annonaceous acetogenins, may inhibit mitochondrial complex I specifically in cancer cells. This proposed mechanism could potentially disrupt energy production within cancerous cells, leading to their reduced viability. However, these effects have primarily been observed in laboratory settings and not reliably demonstrated in living organisms, especially humans.
Long-term or high-dose consumption of soursop, especially its leaves and seeds, has been associated with atypical parkinsonism due to annonacin neurotoxicity. Given the lack of human clinical evidence for anticancer efficacy, its use for this condition carries potential risks without demonstrated benefits. Individuals undergoing cancer treatment should consult their healthcare provider before considering soursop due to potential interactions or adverse effects.
Why it may help Cancer (Adjunctive Support): Green tea, particularly its primary catechin EGCG, has been studied for its potential anticancer properties. Research suggests that EGCG may interfere with cell proliferation, induce apoptosis in cancer cells, and inhibit angiogenesis. This is believed to occur through mechanisms that include antioxidant protection and inhibition of enzymes such as matrix metalloproteinases which are involved in pathways relevant to cancer progression.
While brewed green tea is generally safe, high-dose EGCG extracts have been associated with liver toxicity, which is a particular concern in individuals undergoing cancer treatments that may already impact liver function. Green tea may also interact with certain medications, including some chemotherapy drugs and anticoagulants. It is crucial for individuals with cancer to discuss green tea consumption with their healthcare provider.
Why it may help Cancer (Adjunctive Support): Resveratrol has been studied for its potential role in activating SIRT1 and mimicking caloric restriction pathways, which may influence cellular processes relevant to cancer. It appears to modulate inflammation and induce cell-cycle arrest in various cancer cell lines. These mechanisms suggest a potential adjunctive role in supporting conventional cancer treatments.
Individuals with hormone-sensitive cancers should exercise caution and consult their oncology team before using resveratrol, as its hormonal effects are complex. Potential interactions with chemotherapy drugs have been investigated, warranting professional medical advice. Mild gastrointestinal upset may occur at higher doses.
Why it may help Cancer (Adjunctive Support): Milk thistle, primarily its active compound silymarin, has been studied for its potential antioxidant and anti-inflammatory properties. These actions may help to stabilize hepatocyte membranes and scavenge free radicals, which could be beneficial in supporting liver function during conventional cancer treatments. Silymarin also appears to stimulate liver regeneration and may influence various cellular pathways relevant to cancer development and progression.
Individuals undergoing chemotherapy or radiation should exercise caution due to potential interactions; milk thistle may affect the metabolism of certain drugs. As milk thistle may exhibit estrogenic effects, it is generally advised to be cautious in individuals with hormone-sensitive cancers. Consultation with an oncologist or healthcare professional is crucial before use.
Why it may help Cancer (Adjunctive Support): Boswellia, specifically its boswellic acids, has been studied for its potential anti-inflammatory actions by inhibiting 5-lipoxygenase, which may be relevant in cancer progression. Research also indicates that compounds like AKBA (acetyl-11-keto-β-boswellic acid) appear to show pro-apoptotic activity in certain cancer cell lines, such as glioma and colorectal cancer, suggesting a possible role in adjunctive cancer support.
While generally well tolerated, boswellia may interact with certain chemotherapy drugs, particularly those metabolized by cytochrome P450 enzymes. Individuals undergoing active cancer treatment should consult their oncologist before use to assess potential interactions and contraindications. Its use in specific populations, such as pregnant or breastfeeding women, or those with severe liver or kidney disease, should be approached with caution.
Why it may help Cancer (Adjunctive Support): Sulforaphane, found in broccoli sprouts, appears to influence cellular pathways that are relevant to cancer development and progression. It may act through the activation of the Nrf2 antioxidant pathway, which can promote the detoxification of harmful compounds. Additionally, sulforaphane is studied for its ability to induce phase-II detoxification enzymes, potentially aiding in the elimination of carcinogens.
Individuals undergoing cancer treatment should discuss the use of broccoli sprouts or sulforaphane supplements with their oncologist, particularly due to potential interactions with chemotherapy or radiation therapy. High consumption of raw cruciferous vegetables may impact thyroid function, which could be a consideration for some cancer patients.
Hsu M, Shah A, Jordan A, Gold MS, Hill KP · JAMA · 2026
Approximately 27% of adults in the US and Canada report having ever used cannabis for medical purposes. An estimated 10.5% of the US population reports using cannabidiol (CBD), a chemical compound extracted from cannabis that does not have psychoactive effects, for therapeutic purposes.
Conditions for which cannabinoids have approval from the US Food and Drug Administration include HIV/AIDS-related anorexia, chemotherapy-induced nausea and vomiting, and certain pediatric seizure disorders. A meta-analysis of randomized clinical trials reported a small but significant reduction in nausea and vomiting from various causes (eg, chemotherapy, cancer) when comparing prescribed cannabinoids (eg, dronabinol, nabilone) with placebo or active comparators (eg, alizapride, chlorpromazine; standardized mean difference [SMD], -0.29 [95% CI, -0.39 to -0.18]). A meta-analysis of randomized clinical trials among patients with HIV/AIDS reported that cannabinoids had a moderate effect on increasing body
Häuser W, Welsch P, Radbruch L, Fisher E, Bell RF, Moore RA · The Cochrane database of systematic reviews · 2023 · n=10
Pain is a common symptom in people with cancer; 30% to 50% of people with cancer will experience moderate-to-severe pain. This can have a major negative impact on their quality of life. Opioid (morphine-like) medications are commonly used to treat moderate or severe cancer pain, and are recommended for this purpose in the World Health Organization (WHO) pain treatment ladder. Pain is not sufficiently relieved by opioid medications in 10% to 15% of people with cancer. In people with insufficient relief of cancer pain, new analgesics are needed to effectively and safely supplement or replace opioids.
To evaluate the benefits and harms of cannabis-based medicines, including medical cannabis, for treating pain and other symptoms in adults with cancer compared to placebo or any other established analgesic for cancer pain.
We used standard, extensive Cochrane search methods. The latest search date was 26 January 2023.
We selected double-blind randomised, controlled trials (RCT) of medical
Dykukha I, Malessa R, Essner U, Überall MA · Pain medicine (Malden, Mass.) · 2021 · n=1289
Pooled analysis of nabiximols and placebo in randomized controlled studies (RCTs) of chronic neuropathic pain.
Systematic review and meta-analysis.
A systematic literature search was conducted to identify double-blind placebo-controlled RCTs of nabiximols for chronic neuropathic pain. The clinical endpoint of interest was change from baseline in mean pain score on 11-point numerical rating scales. Mean difference (MD) and standardized mean difference (SMD, Hedges' g) were calculated using fixed effect (FE) and random effects (RE) models. Strength of evidence was assessed using the Cochrane Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. Risk of bias was assessed using the revised Cochrane risk-of-bias tool (RoB 2).
Nine RCTs with 1289 participants were included. Quality of evidence (GRADE) was moderate. One study had a high risk of bias (RoB 2) and five had some concerns. For the pooled endpoint of change from baseline in mean pain score, nabiximols w
Meta-AnalysisPubMedVery High Quality
Systematic Reviews(1)
Structured reviews of the full body of evidence (incl. Cochrane).
Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known.
The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational and public health elements, and future research recommendations. The systematic review of the literature was conducted during 2019, assessing the data from all case studie
Systematic ReviewPubMedVery High Quality
Clinical Guidelines(1)
Recommendations from medical societies (NICE, AHA, ADA, ACG, Endocrine Society…).
National Institute for Health and Care Excellence (NICE)
NICE guideline NG144 covers cannabis-based medicinal products for a range of conditions, including chronic pain, nausea and vomiting. It provides recommendations for prescribing and clinical use based on existing evidence.
Clinical GuidelineNational Institute for Health and Care Excellence (NICE)High Quality
Niño Cital S, Wakshlag J, Kennedy A, Tittle D, Petty M · Journal of feline medicine and surgery · 2025
The use of cannabinoids from hemp, which is classified as a cultivar of Cannabis sativa with up to 0.3% delta-9-tetrahydrocannabinol by USA federal definitions, is becoming increasingly popular in veterinary medicine. Owners frequently ask about their utility in a variety of conditions, including predominantly osteoarthritis, behavioral management, cancer, dermatitis and seizure disorders. Cannabinoid clinical utility, particularly cannabidiol (CBD) in dogs, is gradually emerging, while evidence for its use in cats remains limited. Several newer publications around the pharmacokinetics of CBD and cannabidiolic acid in cats show dramatic differences in bioavailability, elucidating that not all formulations are similar regarding serum or plasma concentrations. To date, although the pharmacokinetics look favorable, there are a handful of clinical studies on feline acute/chronic pain states and fear/anxiety/stress, alongside some pre-clinical studies where there is a potential for clinical
Grimison P, Mersiades A, Kirby A, Tognela A, Olver I, Morton RL · Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2024 · n=250
The aim of this randomized, placebo-controlled, two-stage, phase II/III trial was to determine the efficacy of an oral cannabis extract in adults with refractory nausea and/or vomiting during moderately or highly emetogenic, intravenous chemotherapy despite guideline-consistent antiemetic prophylaxis. Here, we report results of the prespecified combined analysis including the initial phase II and subsequent phase III components.
Study treatment consisted of oral capsules containing either tetrahydrocannabinol 2.5 mg plus cannabidiol 2.5 mg capsules (THC:CBD) or matching placebo, taken three times a day from days -1 to 5, in addition to guideline-consistent antiemetics. The primary measure of effect was the difference in the proportions of participants with no vomiting or retching and no use of rescue medications (a complete response) during hours 0-120 after the first cycle of chemotherapy on study (cycle A).
We recruited 147 evaluable of a planned 250 participants from 2016 to 2022.
Nayak MM, Chai P, Catalano PJ, Pirl WF, Tulsky JA, Tung SC · JAMA network open · 2024 · n=50
Early evidence from studies outside of oncology has suggested that cannabidiol (CBD) may have anxiolytic effects without neuropsychiatric risks. An understanding of oral CBD in patients with cancer-related anxiety is urgently needed.
To determine whether a single 400-mg oral dose of a US Food and Drug Administration-approved CBD improves clinical anxiety in an oncologic population.
This phase II, double-masked, placebo-controlled, randomized clinical trial was performed at the Dana-Farber Cancer Institute's Breast Oncology Center from November 2, 2021, through March 1, 2023. Women aged 18 years or older with advanced breast cancer and baseline clinical anxiety were included.
Patients were randomized 1:1 to receive oral CBD, 400 mg, vs placebo within 48 hours before a scan assessing tumor burden.
The primary end point was a between-arm comparison of change scores on the afraid subscale of the Visual Analog Mood Scale (VAMS) before and 2 to 4 hours after study drug ingestion. The VAM
Randomized TrialPubMedHigh Quality
Observational Studies(52)
Cohort, case-control, and cross-sectional human studies.
Kim NY, Jung YY, Um JY, Ahn KS · IUBMB life · 2025
Pancreatic ductal adenocarcinoma (PDAC) is characterized by aggressive metastasis and poor response to chemotherapy, largely driven by epithelial-mesenchymal transition (EMT) and chemokine signaling. Cannabidiol (CBD), a non-psychoactive phytocannabinoid, has shown anticancer potential, yet its mechanisms in EMT regulation remain underexplored in PDAC. In this study, we demonstrate that CBD significantly suppresses the expression of CXCR4/CXCR7 and matrix metalloproteinases (MMP-2/9), leading to reduced migration and invasion of MIA PaCa-2, PANC-1, and AsPC-1 cells. Moreover, CBD reversed CXCL12-induced EMT by downregulating mesenchymal markers and restoring epithelial markers. Mechanistically, CBD inhibited the expression of the long non-coding RNA MALAT1, a known EMT regulator, and antagonized its pro-invasive effects. Overexpression of MALAT1 activated the PI3K/Akt/mTOR pathway and enhanced EMT-related protein expression, all of which were effectively reversed by CBD. Furthermore, t
Observational StudyPubMedLow Quality
Mechanistic Studies(1)
Lab and in-vitro work explaining how something might work.
Pongking T, Intuyod K, Thongpon P, Thanan R, Sitthirach C, Chaidee A · Journal of traditional and complementary medicine · 2024
Cholangiocarcinoma (CCA) is usually diagnosed at a late stage, leading to treatment failure. Cannabidiol (CBD), exhibits diverse anti-cancer effects in various cancers, offering avenues for improving CCA treatment. This study investigated the effects of CBD on human CCA cells and the underlying mechanisms in vitro and in vivo.
The effects of CBD on three CCA cell lines (KKU-213B, KKU-100, KKU-055) were assessed using the SRB assay, clonogenic assay, cell cycle arrest, and 3D holotomography. Morphological changes were examined using transmission electron microscopy, while mitochondrial ROS levels and mitochondrial membrane potential were studied using MitoSOX, JC-1, and DCFH-DA. Cellular senescence induction was evaluated via SA-β-gal staining. Protein associatedwith autophagy and cellular senescence were analyzed using Western blot and/or immunofluorescent assays. A xenograft model demonstrated the anti-tumor activity of CBD and the induction of cellular senescence through immun
Mechanistic StudyPubMedLow Quality
Animal Studies(4)
Preclinical animal research — not a substitute for human evidence.
Yang F, Duan S, Liu J, An Z, Liu W, Wang X · Phytomedicine : international journal of phytotherapy and phytopharmacology · 2025
Osteosarcoma remains a therapeutic challenge due to its aggressive behavior and high metastatic potential, necessitating exploration of novel treatment modalities. Cannabidiol (CBD), a non-psychoactive phytocannabinoid with emerging anticancer properties, has shown promise in preclinical cancer models. However, its mechanisms of action in osteosarcoma remain incompletely understood. This study systematically investigates the antitumor effects of CBD on osteosarcoma and elucidates its molecular targets within the TNF-α/NF-κB/CCL5 signaling axis.
The effective concentration of CBD was determined using the CCK-8 assay. Functional assays (EdU proliferation, Transwell migration/invasion, and scratch wound healing) evaluated its impact on osteosarcoma cell malignancy. A mouse xenograft model assessed in vivo efficacy. Network pharmacology and RNA-seq identified key pathways, which were validated via ELISA, qRT-PCR, and western blot. Molecular interactions were confirmed through
Sun Q, Bravo Iniguez A, Tian Q, Du M, Zhu MJ · Molecular nutrition & food research · 2024
Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the gut, accompanied by impaired epithelial integrity, increased macrophage infiltration, and enhanced colon cancer risk.
Cannabidiol (CBD), a phytocannabinoid isolated from cannabis plants, is supplemented into mice diet, and its beneficial effects against dextran sulfate sodium (DSS)-induced experimental colitis is evaluated. Eight-week-old mice were fed a standard diet supplemented with or without CBD (200 mg kg-1 ) for 5 weeks. In the 4th week of dietary treatment, mice were subjected to 2.5% DSS induction for 7 days, followed by 7 days of recovery, to induce colitis. CBD supplementation reduced body weight loss, gross bleeding, fecal consistency, and disease activity index. In addition, CBD supplementation protected the colonic structure, promoted tissue recovery, and ameliorated macrophage infiltration in the colonic tissue, which was associated with the activation of cyclic AMP-protein kinase A, e
Xiong X, Chen S, Shen J, You H, Yang H, Yan C · Signal transduction and targeted therapy · 2022
The combination of immune checkpoint blockade (ICB) with chemotherapy significantly improves clinical benefit of cancer treatment. Since chemotherapy is often associated with adverse events, concomitant treatment with drugs managing side effects of chemotherapy is frequently used in the combination therapy. However, whether these ancillary drugs could impede immunotherapy remains unknown. Here, we showed that ∆9-tetrahydrocannabinol (THC), the key ingredient of drugs approved for the treatment of chemotherapy-caused nausea, reduced the therapeutic effect of PD-1 blockade. The endogenous cannabinoid anandamide (AEA) also impeded antitumor immunity, indicating an immunosuppressive role of the endogenous cannabinoid system (ECS). Consistently, high levels of AEA in the sera were associated with poor overall survival in cancer patients. We further found that cannabinoids impaired the function of tumor-specific T cells through CNR2. Using a knock-in mouse model expressing a FLAG-tagg
The WHO provides global health information and statistics on cancer, outlining key facts, risk factors, prevention strategies, and approaches to cancer care, including supportive interventions.
This section of the National Cancer Institute website provides extensive information and resources on coping with cancer, including emotional, practical, and social support. It covers topics such as managing side effects, financial issues, and communication with healthcare teams.
Government SourceNIH National Cancer InstituteHigh Quality
This section of the NCI website provides information on complementary and alternative medicine approaches for cancer patients, detailing their potential benefits and risks.
Government SourceNational Cancer Institute (NCI)High Quality
Clinical Trial Registries(41)
Registered ongoing or completed trials (ClinicalTrials.gov).
Aim of this phase III trial is to investigate the efficacy and safety of dronabinol (orally administered tetrahydrocannabinol (THC)) as adjuvant therapy to first-line standard chemotherapy in patients with metastatic pancreatic cancer for improvement of chemotherapy- and tumor-related symptoms applicated by individual titration up to the maximum tolerated dose.
This study was designed to evaluate the safety and efficacy of Cesamet™ in controlling pain in subjects experiencing pain due to chemotherapy-induced neuropathic pain in patients with cancer.
This will be a proof-of-concept, single arm study with a maximum of 20 patients to evaluate preliminary analgesic efficacy and safety of Trichomylin® in patients with advanced cancer (male and female) who suffer from moderate to severe chronic pain and who are taking a stable dose of long-acting opioid therapy for at least 1 week prior to screening.
Clinical TrialClinicalTrials.govModerate Quality
Evidence Summaries(7)
Curated cross-source summaries (TRIP Database and similar).
Cochrane provides systematic reviews and meta-analyses of healthcare interventions, offering high-quality evidence on various adjunctive therapies used in cancer care to support clinical decision-making.
The Cochrane Library provides high-quality, independent evidence to inform healthcare decision-making, including systematic reviews relevant to various aspects of cancer and adjunctive support.
The TRIP Database is a clinical search engine designed to allow users to quickly and easily find high-quality research evidence to support their practice, including numerous resources on cancer and its supportive care.
Evidence SummaryTRIP DatabaseHigh Quality
Working alongside conventional care
Conventional cancer care typically involves a multi-modal approach, which may include surgery, chemotherapy, radiation therapy, immunotherapy, and targeted drug therapies. Diagnoses are commonly established through biopsies, imaging studies, and blood tests, with treatment plans tailored to the specific type, stage, and location of the cancer. These treatments aim to remove, destroy, or control cancer cells.
Related conditions
Chemotherapy-induced nausea and vomitingCancer-related fatigueCancer painCachexiaPeripheral neuropathyLymphedema
The information provided is for educational purposes only and should not be considered medical advice. Always consult with your oncology team before starting, stopping, or changing any adjunctive therapies, as they can interact with conventional treatments.
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