Watch out: Mexican poppy plant doesn't cure cancer, might poison you
IN SHORT: Social media posts claim that a common weed known as Mexican poppy can cure multiple types of cancer and sexually transmitted infections, with one video instructing viewers to eat the plant or drink tea made from it. But there is no research to back this up, and all parts of the Mexican poppy plant are considered toxic.
"If you are struggling with prostate cancer and kidney, please try this remedy. I tell you, it's not dangerous, as people are saying in the comments section."
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This is according to the narrator of a popular video circulating on Facebook in December 2025. The video shows a spiky weed-like plant with yellow flowers, identified as a Mexican poppy.
Other posts suggest the plant can treat a range of conditions, from gout to HIV, or human immunodeficiency virus, and other sexually transmitted infections (STIs). But multiple comments on the video post also warn that the plant is dangerous. We took a closer look at the science.
Traditional use of Mexican poppy
The video suggests a few methods of consumption, instructing people to "take the leaves, roots, boil them and drink", dry them and use them as teabags, or "burn them and eat the powder".
The plant is indigenous to the Americas but is found in many countries worldwide. In South Africa, it is also known as "ugudluthukela" in isiZulu and "geelblombloudissel" in Afrikaans.
Its use in traditional medicine is widely documented, including for malaria, skin disorders, wound healing, pain relief, and the treatment of eye, liver and dental issues.
Traditional medicine generally focuses on nature-based treatments to "restore balance of mind, body and environment". It is usually thought of as distinct from medications that have been scientifically proven, though many of the most commonly prescribed medicines, like contraceptives, anti-cancer and anti-malaria drugs, are based on traditional knowledge and come from nature.
So what does scientific research say about this plant?
Research into medical use
Popular health claims are often based on research but remain scientifically unproven. This happens because in medical research, different types of studies are designed to test different ideas.
To test whether a substance can become an effective treatment, researchers conduct basic research in a lab to evaluate what the substance does and how it works. If it seems promising, researchers will assess what it does to individual cells and to animals in a laboratory, to evaluate its effectiveness and safety.
Eventually, after many studies involving human participants, a medicine might be approved for use if it is proven to be safe and effective. This process takes a long time, and very often medicines that start in lab studies don't show enough potential to move on to more studies.
We can see this with the Mexican poppy plant. Some plant-derived ingredients have shown promise in killing colon cancer cells in the lab or in delaying tumour formation in mice. But there are no similar studies in humans, yet.
Other studies have found that the plant, or its specific ingredients, might help fight malaria, including in humans, supporting this traditional use. But using this plant can also be extremely harmful.
All parts of the plant are toxic
Because the seeds of the Mexican poppy plant look very similar to mustard seeds, there have been many cases of mustard cooking oil being mixed with Mexican poppy oil, which makes the mixture poisonous.
There have been major outbreaks of a condition called epidemic dropsy after people consumed mustard oil mixed with oil made from the poppy. This has previously been reported in South Africa, India and other areas, where many people have become ill or died after consuming the oil.
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Specific ingredients in the plant have also been found to be highly toxic in scientific research on animals. In South Africa, the plant is also listed as poisonous to farm animals, including sheep, chickens and cattle. All parts of the plant are considered toxic.
While some ingredients in the plant may have promising future uses and its use in malaria treatment is well documented, this does not mean that consuming any part of the plant will help treat cancer, gout, STIs and the many other conditions suggested on social media. And it is well known that some ingredients in the plant can be dangerous, even deadly.
It is important to speak to a medical professional before trying this remedy. Evidence-based medicines are available to treat or cure these conditions.
