While there’s evidence to support the use of several nutrients and supplements in the fight against COVID-19, oleandrin, a compound from the oleander plant, is not one of them.
Rumors about the possibility of an oleandrin remedy have been swirling in recent weeks following the posting of a study1 on the preprint server bioRxiv, in which oleandrin was found to inhibit the replication of SARS-CoV-2 in vitro. According to the authors:2
“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 …
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.”
Do Not Attempt to Use Oleander as a Home Remedy
It’s important to note that this was an in vitro test, meaning these results were observed in cell culture. It has not been tested on animals or humans. The reason this is a crucial distinction is that the oleander plant is well-known for its extreme toxicity.
The fact that it killed the virus in a cell culture does not suggest it would be an effective remedy for the simple fact that its high toxicity just might kill the patient along with the virus. So, please, DO NOT attempt to use this plant as a home remedy against COVID-19.
Oleander grows well in subtropical climates such as Florida and is toxic to pets. I strongly advise against growing oleander in your yard if you have pets or small children (and if you do, make sure they’re supervised around the plant), or harvesting the plant as a potential remedy. The results could be lethal.
This is definitely an instance in which we must allow scientists to methodically work through the scientific process to determine if, in fact, there’s a way to turn oleandrin into a useful drug.
American Botanical Council Issues Advisory
Among those who have issued urgent advisories against the use of oleander is the American Botanical Council (ABC), also known as the Herbal Medicine Institute — an independent, nonprofit research and education organization.3
When it comes to plants, herbs, and botanicals, they are a premier expert resource. In an August 18, 2020, advisory, the ABC warns consumers against producing oleander-based home-remedies due to the plant’s extreme toxicity:4
“ABC warns consumer not to ingest any parts of the plant, or capsules, tablets, teas, or extract preparations made from leaves or other parts of the oleander plant because it contains chemicals that can cause serious effects to the human heart, including death …
Oleander is a large white- or pink-flowering bush or small tree that is grown as an ornamental plant in many parts of the United States and elsewhere, including north Africa, the Mediterranean, and southwestern Asia.
All parts of the plant contain a poisonous substance called oleandrin, known technically as a cardiac glycoside, and other similarly toxic constituents. The structure of oleandrin and its activity are similar to digoxin, a glycoside from the equally toxic foxglove plant … Digoxin is a pharmaceutical drug used in conventional cardiology for heart failure and irregular heartbeat.
ABC does not know of any extracts or dietary supplement products sold in the U.S. that contain oleander. Oleander plant parts and its extracts are not sufficiently safe to be sold in dietary supplements …
According to ABC Founder and Executive Director Mark Blumenthal, ‘To be clear, ABC applauds appropriate scientific research into medicinal plants and fungi as sources of new medicines. We also acknowledge the very promising medical research conducted by Phoenix Biotechnologies and their oleandrin formulations.
However, ABC emphasizes the distinction between a scientifically studied, chemically-defined experimental new drug compound from a widely known poisonous plant and a simple home-made pill, tea, or extract made from the plant’s various parts.
With respect to oleander, all parts of the plant are highly toxic, dangerous, and life-threatening when ingested. Consumers should not, ever, try to make a home-made remedy from or self-treat with oleander.’”
Extreme Toxicity of Oleander
To get an idea of just how toxic oleander can be, consider this 2006 case report5 of two individuals who came down with several adverse symptoms, including nausea, vomiting, diarrhea, and abnormal cardiac sinus rhythm, after eating a stew made with snails that had consumed the plant.
Their symptoms were diagnosed as being the result of toxic exposure to oleandrin and oleandrigenin, the presence of which was found in the snails. Other medical case reports have noted that:
• Oleandrin causes arrhythmia by interfering with the sodium-potassium pump of your heart. Ingestion of any part of the oleander plant is also associated with gastrointestinal effects, such as nausea, vomiting, and diarrhea.
Both cardiac and gastrointestinal effects appear approximately four hours after ingestion. Even the smoke of the plant, when burned, is toxic. As noted by the authors, “Practicing physicians should understand the potential lethal properties of oleander and its availability throughout the world.”6
• According to a 1982 case report, 4 grams of oleander leaves provided a fatal dose of toxic glycosides.7
• A 2019 paper reported a fatal case of self-poisoning through the voluntary ingestion of oleander leaves. Toxic blood levels of oleandrin were estimated at 1 ng/mL to 2 ng/mL. Levels above 9.8 ng/mL are thought to be fatal.8
The authors of that 2019 paper point out that while oleander poisoning is typically accidental, knowledge about the plant’s toxicity could be used as a method for suicide (or homicide, for that matter).
Considering the fact that rates of depression, anxiety, and suicide are currently higher than ever,9,10 putting this information out there is a bit of a double-edged sword. If you are depressed, I urge you to seek professional help.
Oleandrin Is a Cardiac Toxin
On August 18, 2020, an article published by The Conversation,12 medical ethnobotanist Cassandra Quave also warns against self-medicating with oleander, noting that while more than 28,000 plant species are recognized for their medicinal value, not all plants are safe.
The oleander plant in particular has been responsible for poisonings all around the world.13 Again, all parts of the plant, including the smoke when burned, are poisonous. “If eaten, it causes cardiac arrhythmias, or irregular heart rates, and can be lethal to both humans and animals,” Quave warns.
Other potential side effects14 include dizziness, blurred vision or other vision disturbances, low blood pressure, drowsiness or fainting, and headache. In nonlethal instances, symptoms can last up to three days, and frequently require hospitalization due to their severity. Quave adds:15
“Oleandrin 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 … 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.”
So, in closing, as reviewed in “Essential Nutrition to Protect Yourself From Coronavirus” and many other articles, there are several nutritional supplements that have significant scientific backing for their use against respiratory infections, including COVID-19. Oleander is not a safe medicinal plant, and I strongly advise against any attempt to use any part of the plant to self-medicate against any condition whatsoever.