Beware Oleandrin, It is a Deadly Cardiac Poison, Not a COVID-19 Cure

At The Conversation, Cassandra Quave (Assistant Professor of Dermatology and Human Health; Herbarium Curator, Emory University) has written a helpful article expressing her concern that the dietary supplements industry may try to take advantage of the public’s fear of COVID-19 by developing supplements containing oleandrin.

Interestingly, oleandrin is a cardiac glycoside like digitalis. I’ve written a lot about my love for the foxglove plant from which digitalis is obtained. Like digitalis, oleandrin has the potential for lethal cardiac rhythm abnormalities and comes from a beautiful plant.

Supplements and vitamins of various sorts have been widely and wildly recommended during COVID-19 with little good data to support any particular one.

The Cleveland Clinic Journal of Medicine published a nice review on the topic published in June which concludes:

Ascorbic acid, zinc, vitamin D, and N-acetylcysteine have biologic plausibility for the prevention and treatment of COVID-19 and are candidates for clinical trials evaluating patients with these indications. Although there is likely little risk for patients taking labeled over-the-counter doses of these supplements, clinical evidence does not currently support routine use of any of these agents for the prevention or treatment of COVID-19. Unless a patient has a confirmed or suspected micronutrient deficiency, additional research is needed before providing doses of these agents higher than the recommended daily intake established by the US Department of Agriculture.

I’ve been watching this area closely and feel it remains a good summary as of today, August 18, 2020. I have to admit that I had been diagnosed with low Vitamin D levels a year ago but had not been consistently taking my Vitamin D pills. Once COVID-19 began and an apparent association between low Vitamin D levels and severity of disease emerged I began taking my pills as prescribed.

Please note that these four supplements present little risk but many other supplements interact with prescription medications which can cause life-threatening adverse effects. In addition, unlike prescription medications, the supplement industry is not regulated by the FDA and you have no guarantees of safety, efficacy or event the content of OTC supplements.

The Conversation article is below the dots.

With COVID-19 cases and deaths rising in the U.S. and globally, identifying new therapies to prevent and combat the virus is a top priority. Natural products from plants are an attractive option in the search for a cure. Approximately 374,000 plant species are on Earth; humans have used more than 28,000 of them as a form of medicine. 

But not all that is natural is necessarily safe. Scientists have not yet explored most of these species for their chemical makeup or therapeutic potential. 

As a medical ethnobotanist, I study the traditional uses of medicinal plants to discover promising leads for new drugs to fight infectious diseases. It’s vital to consider both the potential benefits and risks of plant extracts in such research. I am concerned by recent reports that a chemical found in the oleander plant is being touted as a potential treatment for COVID-19. 

About the Oleander plant

Nerium oleander is a highly toxic plant from the Apocynaceae family. Though renowned for its beauty and use in landscaping, this Mediterranean shrub is responsible for cases of accidental poisoning across the globe. All parts of the plant are poisonous. If eaten, it causes cardiac arrhythmias, or irregular heart rates, and can be lethal to both humans and animals. 

A drawing of the chemical structure of oleandrin.
The chemical structure for oleandrin, the toxic compound in the beautiful plant oleander. Casssandra Quave, CC BY-SA

Oleandrin is the chemical that causes the plant’s lethal toxicity. It is known by scientists as a cardiac glycoside, a class of organic compounds with a common feature: They exhibit powerful effects on heart tissue, often with deadly consequences.

A pre-print article – that is, an article not peer-reviewed by other scientists – is now online. It reports how, in a test tube, oleandrin reduces production of the virus responsible for COVID-19. But this does not take into account the well-known cardiac toxicity of the chemical when consumed by an animal or human.

Particularly worrisome is the idea that consumers may misinterpret any publicity surrounding oleander and try to self-medicate with this highly poisonous plant. I’m also concerned the dietary supplements industry may try to take advantage of the public’s fear of COVID-19 by developing supplements containing oleandrin. 

There are many other examples of natural plant extracts that are harmful. But oleander is particularly dangerous, because ingesting any part of the plant can lead to serious illness and possibly death. What’s more, there is no published scientific evidence on the safety of consuming oleandrin or its plant source, Nerium oleander. It is critical that the Food and Drug Administration and its commissioner, Dr. Stephen Hahn, make certain the public is protected from this poison.

I will definitely be steering clear of oleander supplements during COVID-19 but hope to add Nerium oleander to my garden of cardiologogic plants in the near future.

Digitallicly Yours,



24 thoughts on “Beware Oleandrin, It is a Deadly Cardiac Poison, Not a COVID-19 Cure”

  1. ACP: did I answer your questions adequately that you needed? BTW, in contrast to what you implied I said, I am NOT interested in going back to the bad old days. But information from the past can be helpful. The human biology is 90% ideally organic whole foods vegan wi anything once in a while. Check out our salivary enzyme, grinding/not slicing jaw action, lack of fangs & claws, inability to digest rotten meat,… Just because we can I want for you to my cable is isdo whatever does not mean we should. What do you think the non-HDL cholesterol, triglycerides, percent body fat, BUN, magnesiuQuestion supposedly IN the and is as is is is is is is is is is is is is ism, blood pressure, … Is in vegan’s? All those numbers in vegans (as difficut as that is, are at the level where risk regresses to zero for the simultaneous prevention of multiple diseases.

  2. In 1967, freshly returned from Vietnam, a veteran was celebrating with his family in Santa Barbara. They were roasting hot dogs when the veteran became ill. He was taken to the hospital but subsequently died. Cause of death: Oleander poisoning from the branch he had cut to roast his hot dog. Having returned myself at nearly the same time the irony of having cheated death in war only to fall victim at a welcome home party is something I have never forgotten.

    I think Dr. Pearson’s “Heads up” warning is appropriate and a public service.


  3. I take the supplements you mention (except Oleandrin) and a few more. You forgot to mention taking enough pharmaceutical grade omega 3 to get your AA/EPA ratio between 1 and 3. Americans consume way too many pro-inflammatory omega 6 fatty acids from the vegetable oils in highly processed food. As you know, COVID-19 thrives on total body inflammation, so both before getting sick and after getting ill, suppressing inflammation is critical. I learned much of what I know about this topic from my good friend Barry Sears of Zone Diet fame. I don’t think his diet makes sense, but Barry is a biochemist by training and he knows inflammation inside and out. His last book “The Resolution Zone” is an excellent resource on this issue. By the way, congratulations on the new job. Soon I will be starting three part time jobs and that’s not too bad for a 72 year old Family Physician with a 6 year old daughter!

    • By the way, you must know the reason no controlled studies are done on supplements. It’s because Big Pharma can’t patent supplements, so they can’t make and money. The exception is the only vitamin approved by the FDA to treat a disease–L-methyfolate (the active form of folic acid) is approved to treat depression under the name Deplin. Combining L-methylfoate, pyridoxal 5′-phosphate, methyl-cobalamin and trimethylglycine is a very effective way to lower homocysteine, and as you likely know, high homocysteine is very toxic to your circulation and brain.

      • It’s odd you should mention methylfolate. My homocysteine levels are persistently high so I recently purchased a bottle.

        • You might get methyl malonic acid & anti-parietal Ab lab tests to be certain u do not have Pernicious Anemia. If those tests are negative, then ask yourself “What about my diet is the likely cause of my high homocysteine?” There probably is an answer as well as the solution in what I said above about the human biology. Almost all Western diseases have causes that are often correctable naturally. Just by-the-by, I am NOT entirely vegan.

          • I have normal methyl malonic acid.slightly low B 12 which is mostly related to having a large segment of ileum removed.

    • Oleander is well known along the “Low Country” of the Carolinas & Georgia for being toxic. In years past a “get out of the draft” tea was brewed from oleander which if properly dosed caused arrhythmias. Unfortunately, the oleander tea did cause some deaths.

  4. From the Sloan Kettering website: “Experiments suggest that a combination of Anvirzel (an oleander extract) and cisplatin may be more effective than cisplatin monotherapy (28). In an earlier study, Anvirzel appeared safe in humans when injected intramuscularly, although adverse effects such as injection site pain, fatigue, and other GI symptoms were reported (12).

  5. Here is the article that started the oleandrin discussion about he Rx of CoV2-19: note th low concentration

    Prophylactic and Therapeutic Inhibition of In Vitro SARS-CoV-2 Replication by Oleandrin
    Kenneth S. Plante, Jessica A. Plante, Diana Fernandez, Divya Mirchandani, Nathen Bopp, Patricia V. Aguilar, K. Jagannadha Sastry, Robert A. Newman, View ORCID ProfileScott C. Weaver
    This article is a preprint and has not been certified by peer review [what does this mean?].


    With continued expansion of the COVID-19 pandemic, antiviral drugs are desperately needed to treat patients at high risk of life-threatening disease and even to limit spread if administered early during infection. Typically, the fastest route to identifying and licensing a safe and effective antiviral drug is to test those already shown safe in early clinical trials for other infections or diseases. Here, we tested in vitro oleandrin, derived from the Nerium oleander plant and shown previously to have inhibitory activity against several viruses. Using Vero cells, we found that prophylactic oleandrin administration at concentrations down to 0.05 μg/ml exhibited potent antiviral activity against SARS-CoV-2, with an 800-fold reduction in virus production, and a 0.1 μg/ml dose resulted in a greater than 3,000-fold reduction in infectious virus production. The EC50 values were 11.98ng/ml when virus output was measured at 24 hours post-infection, and 7.07ng/ml measured at 48 hours post-infection. Therapeutic (post-infection) treatment up to 24 hours after infection of Vero cells also reduced viral titers, with the 0.1 μg/ml dose causing greater than 100-fold reductions as measured at 48 hours, and the 0.05 μg/ml dose resulting in a 78-fold reduction. The potent prophylactic and therapeutic antiviral activities demonstrated here strongly support the further development of oleandrin to reduce the severity of COVID-19 and potentially also to reduce spread by persons diagnosed early after infection.

    IMPORTANCE COVID-19, a pandemic disease caused by infection with SARS-CoV-2, has swept around the world to cause millions of infections and hundreds-of-thousands of deaths due to the lack of vaccines and effective therapeutics. We tested oleandrin, derived from the Nerium oleander plant and shown previously to reduce the replication of several viruses, against SARS-CoV-2 infection of Vero cells. When administered both before and after virus infection, nanogram doses of oleandrin significantly inhibited replication by up to 3,000-fold, indicating the potential to prevent disease and virus spread in persons recently exposed to SARS-CoV-2, as well as to prevent severe disease in persons at high risk. These results indicate that oleandrin should be tested in animal models and in humans exposed to infection to determine its medical usefulness in controlling the pandemic.

    • So problems as pointed out by Dr. Quave are
      1. This is a preprint. It has not been reviewed by anybody for its scientific validity
      2. It reduces viral production in Vero cells. Not in humans. Or any animals. Clorox bleach is also effective.
      3. The dosage for any effect in humans is totally unknown and I suspect will never be known.

  6. The concern, of course, is that the influence of the office of the POTUS (Such as it is) might very well exacerbate this oleander temptation for certain trusting people. Why not just say as much?

  7. It is always important not to jump to conclusions. As usual, ACP presents important information. However he does not present information that taking oleandrin may be entirely safe and helpful if taken in the proper dose. I often chide him to present his information with more humility. What is the correct dose? I do not have the answer to that and I urge caution in the use of oleandrin as with ANY medication or supplement, but I do not advise black-and-white positions such as ACP has taken here. Fauci has waffled and mislead on too many issues. He is a political activist and NOT to be trusted re the corona virus. The arrival of a more balanced MD = Scott Atlas to the White House Covid team is entirely welcome. HRS, MD, FACC

    • In reply to Dr. Silverstein,
      Are there references for the assertion that taking oleandrin may be helpful in the treatment of Covid-19 in the proper dose. (Something more than the test-tube replication inhibition mentioned above…that counts for next to nothing). Myself, I knew nothing about the political activism of Fauci or Atlas. What little looking around I did led on the me to find lots of political activity by Atlas and none by Fauci. (I am not arguing that one or both of them may or may not have some political agenda…how could I now?…but Atlas has an overtly political history.) As a clinician, I can appreciate the waffling of Fauci, because it reflects the uncertainty of our knowledge here and now. While I appreciate some of the arguments Atlas has made (despite him making his arguments with a certainty that makes me suspicious. Actually, I wish he would waffle more!). Also, I do tend to favor the advice of someone who has trained in internal medicine and viral disease and immunology over someone who trained in neuroradiology when it comes to managing a viral outbreak.

      Hopefully it didn’t bias me too much, but I did care for a patient in the ER who died after ingesting oleander tea for cold symptoms. Clearly, if there is a “correct dose”, she went way over that. People do need to be careful in any case. Thanks.

      • It would appear Dr. Silverstein would like us to harken back to the days of William Withering who learned by trial and error how much of the foxglove his patients could tolerate before vomiting or displaying dangerously low heart rates. Fortunately after centuries of research and study, digoxin has emerged from the foxglove in dosing forms that are mostly safe and reliable.
        One conclusion I am always willing to jump to is that we should not administer drugs/supplements to patients until we have good information on their safety and efficacy. Such is the case clearly for oleander.
        I’m afraid I know nothing about Atlas but I am in total agreement that Fauci’s waffling is totally understandable and laudable, much more so than false confidence.

  8. Interesting. I’ve been supplementing myself with 10 grams of ascorbic acid, lysine, and proline daily, for several years before COVID-19’s ascension. I also supplement with 5000 IU D3, along with my 6.25mg Carvedilol (twice daily) and 10mg Atorvastatin (once daily) which I take due to hypertension and a high calcium score, with a slightly elevated LDL. So far, no problems (knock on wood) contracting COVID.

  9. I enjoy reading your skeptical views on COVID therapies.

    Having debunked so many therapies, what is your advice for an at-risk person the day he notices possible symptoms.

    If I’m not mistaken, Dr. Fauci’s advice is W&S (wait & see).

    Does anyone offer any anti-hospitalization strategies?


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