Influencer Ellie Grey makes unsupported claims about cancer cures

8 August 2023
What was claimed

THC, IV vitamin C, essiac tea, LDN, mistletoe therapy, apricot kernels, alkaline diets are all cancer cures.

Our verdict

None of these have been shown to be effective in treating cancer in humans.

An Instagram post by influencer Ellie Grey contains the claim that there are “hundreds of cures” for cancer and gives examples of these—none of which have been shown to be effective against the disease.

The list given is “THC, IV vitamin C, essiac tea, LDN, mistletoe therapy, apricot kernels, alkaline diets”.

We contacted Ms Grey to ask for clarification. She did not respond to us directly, but acknowledged our message and posted screenshots of various scientific studies on Instagram and in a now-deleted Facebook post. None of these show that the treatments listed are safe and effective cancer “cures”. They are mostly animal or cell studies, which are generally considered to be among the least robust kinds of scientific evidence

We have previously fact checked false health claims made by Ms Grey.

False, misleading or unevidenced claims about cancer can cause harm if people make treatment decisions based on them. We have written about claims that certain foods or alternative therapies can cure or prevent cancer many times before, including some on this list. Delays in getting effective cancer treatment can have life-threatening results.

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THC (or tetrahydrocannabinol) is the psychoactive compound in cannabis. We have previously fact checked claims that cannabis cures cancer, and while it can improve quality of life for people on conventional cancer treatments, the evidence for impact on the actual disease is scarce.

Professor Edzard Ernst, emeritus professor at the University of Exeter, previously told Full Fact: “Cannabinoids have been shown to reduce the size of prostate cancers in animal models. Isolated case reports have yielded encouraging findings also in human cancers, for instance, acute lymphoblastic leukaemia. 

“However, case reports cannot be considered reliable evidence, and there is currently no data from rigorous clinical trials to suggest that cannabis products will alter the natural history of any cancer.”

Ms Grey posted a screenshot [ninth slide] of an article about cannabis and cancer, titled “Cannabis Use in Patients With Cancer: A Clinical Review”. The review is positive about cannabis use for symptom control (especially nausea and low appetite). 

She also highlights a section on anti-proliferative effects (reducing cell growth or spread) of cannabinoids (CBs—another type of compound in cannabis that is not the same as THC). It references other studies that have shown this effect with breast cancer cells (although it should be noted some of these studies have found the CBs to increase cell growth). It also refers to a study that showed some breast cancer cells had receptors that interact with CBs, but this doesn’t mean they affect the cells. 

The section ends noting “there are not yet clinical data evaluating the effect of [...] CBs on treatment outcomes or disease prognosis of any breast cancer subtype”.

On anti-cancer action, the review notes that a National Academy of Sciences committee found that “there is insufficient evidence to support or refute the conclusion that cannabinoids are an effective treatment for cancers”, but that lab and animal studies “suggest additional clinical research needs to be conducted”.

The review doesn’t provide evidence that cannabis or THC cures cancer.

In the now-deleted Facebook post, Ms Grey also included a screenshot of an American Cancer Society webpage that says “More recently, scientists reported that THC and other cannabinoids such as CBD slow growth and/or cause death in certain types of cancer cells growing in lab dishes. Some animal studies also suggest certain cannabinoids may slow growth and reduce spread of some forms of cancer.”

However, the webpage also goes on to say that the studies so far “do not show that [cannabinoids] help control or cure the disease” and makes no mention of THC having any anti-cancer effect in humans or even animals.

IV Vitamin C

We have previously fact checked whether vitamin C can cure cancer, finding it to be an area of ongoing research.

The US National Cancer Institute details the available evidence, which does not show effectiveness for IV vitamin C alone, and mixed results in combination with other drugs (such as conventional chemotherapy). This evidence is far from showing that the substance effectively contributes to treating cancer when used with other medications, and there is no evidence that it does this on its own.

Essiac tea

Essiac is a blend of herbs that has been marketed as an alternative cancer treatment for around 100 years. The overall evidence from animal and lab studies are very mixed, with findings of positive and negative impacts as well as no effect.

The US National Cancer Institute says that: “No results of clinical studies with people of Flor Essence [a brand of essiac tea] have been reported. In addition, no reports of clinical trials of Essiac have been reported in peer-reviewed scientific journals.”

Ms Grey shared [slide 10] a study titled “Essiac tea: scavenging of reactive oxygen species and effects on DNA damage”. The paper, from 2005, references some of the lab studies we’ve mentioned that showed some anti-cancer activity. However, as we’ve also said, other studies showed the opposite or no effect. 

In any case, these researchers were looking at the effect on mouse immune cells that they had exposed to chemicals to cause damage, and seeing if exposing them to essiac tea prevented some of this damage, which it seemed to. The study does not tell us whether essiac could cure cancer.


This refers to low dose naltrexone, with naltrexone being a medication that has been used for decades to treat opioid and alcohol addiction. Memorial Sloan Kettering Cancer Center notes that there is little evidence for its use outside of these conditions, though it is being promoted by some as a treatment for many diseases, including cancer.

Ms Grey posted two studies regarding this. The first was “Naltrexone at low doses (LDN) and its relevance to cancer therapy” [slide 3] and the second was the abstract of “Naltrexone’s Impact on Cancer Progression and Mortality: A Systematic Review of Studies in Humans, Animal Models, and Cell Cultures” [slides 4 and 5].

The first is a review that is generally positive about the possible uses of LDN to treat cancer and other diseases like psoriasis and Crohn’s, but notes “there have been no significant randomized studies to date” and points to “anecdotal reports of activity”, citing only case reports in humans. The authors say these “support clinical trials of LDN in cancer, especially when given in combination with certain chemotherapy” and suggest a need to “explore LDN in a range of oncological conditions”. They do not at any point suggest naltrexone is a proven treatment for cancer either alone or with other drugs—much less a cure.

The second is a systematic review looking at a wide range of studies (as referred to in the title). It found one human randomised control trial (or RCT, the gold standard type of study for health interventions) and one crossover randomised trial (similar to an RCT, but during the trial people given the treatment are swapped to the control and vice versa) as well as other, lower quality evidence such as case reports. 

The RCT is from 1993 with 21 patients. The crossover trial was looking at blood test results (but no clinical outcomes) in 14 patients with untreatable cancers. Both did find ‘positive’ results, but both did use other treatments (radiotherapy and chemotherapy respectively), and the small numbers used limit how much we can conclude from them.

Indeed, the review authors only say: “While definitive conclusions or recommendations cannot be made at this time, this review suggests potential beneficial effects of LDN on cancer progression for oncology patients.”

Mistletoe therapy

Ms Grey posted a screenshot [slide 7] of the website of the US university and medical research centre Johns Hopkins about mistletoe extract. The article  describes a phase I trial that aimed to find out the highest tolerable dose that could be given to people who had already received multiple other cancer therapies. The article is clear that changes in tumour size “did not meet official criteria for partial response”, meaning it did not have enough of an effect on the tumour size to say that the cancer responded to treatment.

A 2020 Cochrane review, often considered the best form of evidence for medical treatments, found that the evidence from randomised control trials (the ‘gold standard’ for medical trials) was weak, for impact on survival, improved ability to fight cancer or to withstand anticancer treatments.

It did find “some evidence that mistletoe extracts may offer benefits on measures of [quality of life] during chemotherapy for breast cancer, but these results need replication”. 

It did not find proof that mistletoe treatment is a cure for cancer.

Apricot kernels

We have previously fact checked claims that the compound amygdalin in apricot kernels cures cancer. 

A Cochrane review found that anti-cancer claims are “not currently supported by sound clinical data”, and carry a significant risk of harm from cyanide poisoning. 

After Full Fact contacted her, Ms Grey posted on Instagram a screenshot [slide 6 and 8] of the abstract of a study which purports to outline the “possible role of naturally occurring amygdalin in fight against cancer and mistaken belief about cyanide toxicity causing potential of amygdalin [sic]”.

It includes reference to lab studies on cells and potential anti-cancer action of amygdalin. However, when it then goes on to reference actual clinical studies, the authors conclude that “Amygdalin trials were conducted 35 years ago and study design did not comply with today’s standards, therefore, a well-designed clinical trial will now be valuable.”

It also notes one trial conducted by the National Cancer Institute which found “there was definite elevation of cyanide in blood” in patients given oral amygdalin. This is the only study of cyanide levels it references, so it’s not clear what the authors are referring to in the abstract conclusion when it says cyanide toxicity is a “mistaken belief”.

We have contacted the researchers involved to ask about this discrepancy, and have not received a response at time of writing.

Alkaline diets

And finally, we have also previously fact checked claims that alkaline diets can cure cancer. As we said at the time, a 2016 systematic review in the British Medical Journal  found no evidence that an alkaline diet can change the likelihood of getting cancer, or the outcomes after diagnosis.

Featured image courtesy of formulatehealth

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