Show Notes

Glyphosate is the most widely used herbicide in the world, and there is a very good chance it is already inside your body.

In this solo episode of The Dr Kumar Discovery, Dr. Ravi Kumar takes a deep dive into glyphosate, the chemical sprayed on nearly every conventional farm field in America. From its strange origin as a failed antibiotic to its current status as a compound the US government has declared a matter of national security, this episode traces the science, the history, the politics, and the practical steps you can take to reduce your exposure.

In this episode, you will discover:

• The surprising history of glyphosate, from a shelved 1950s antibiotic experiment to an industrial pipe cleaner to the most heavily used agricultural chemical in US history
• How glyphosate works by blocking the shikimate pathway in plants, and why that same pathway exists in your gut bacteria
• The two routes glyphosate enters your food: GMO crop spraying and pre-harvest desiccation, a practice that produces much higher residue levels in oats, wheat, barley, and lentils
• Why the regulatory picture is split: the EPA says “not likely carcinogenic” while the WHO classifies glyphosate as “probably carcinogenic to humans”
• The 2023 UC Berkeley systematic review that found strong evidence for genotoxicity and endocrine disruption
• The 2025 Global Glyphosate Study by the Ramazzini Institute, the most comprehensive independent long-term animal study ever conducted, which found tumors, DNA damage, and endocrine disruption at doses regulators currently consider safe
• How glyphosate disrupts your gut microbiome and may reduce production of tryptophan, a precursor to serotonin
• Evidence linking glyphosate to endocrine disruption, liver damage, nonalcoholic fatty liver disease, and ALS risk
• Why the US government invoked the Defense Production Act in February 2026 to boost glyphosate production
• Five practical steps to reduce your glyphosate exposure, from buying organic to filtering your water

Key Takeaways

• Glyphosate is in your food right now. It has been detected in human urine, blood, and breast milk, and the FDA’s own testing found it on 63% of corn and 67% of soybean samples
• The shikimate pathway does not exist in human cells, but it does exist in your gut bacteria, which means glyphosate can disrupt the microbiome even though it was marketed as harmless to humans
• Pre-harvest desiccation, spraying glyphosate on crops right before harvest, produces much higher residue levels than growing-season application. This is why oat-based products consistently test high
• Over 100,000 people have sued the manufacturer claiming glyphosate caused their non-Hodgkin lymphoma, and over $10 billion in settlements have been paid
• Switching to organic oatmeal and organic grains is the single highest-impact dietary change for reducing glyphosate exposure
• Reverse osmosis water filtration effectively removes glyphosate from drinking water
• The precautionary argument is strong: when a compound has multiple plausible mechanisms of harm and biological evidence of harm at current exposure levels, the burden of proof should be on demonstrating safety

Transcript

[00:00 –> 00:16] Dr. Ravi Kumar: On this episode of the Doctor Discovery. By 2007, glyphosate was the most heavily used agricultural chemical in US history. This is not a chemical you can choose to opt out of. Glyphosate is in your food right now.

[00:16 –> 00:42] Dr. Ravi Kumar: And most people have no idea. Is glyphosate actually bad for our bodies? The history is genuinely fascinating and a little strange. It’s hard to look at the totality of this evidence and conclude that glyphosate is doing nothing to our biology. Our government is not just allowing this compound in our food supply, they’re actively pushing to make more of it.

[00:42 –> 01:20] Dr. Ravi Kumar: My name is Doctor Ravi Kumar. I’m a neurosurgeon in search of the causes of human illness and the solutions that help us heal and thrive. I want you to join me on a journey of discovery as I turn over every stone in search of the roots of disease and the mysteries of our resilience. The human body is a mysterious and miraculous machine with an amazing ability to self heal. Let us question everything and discover our true potentials. Welcome to the Doctor Kumar Discovery.

[01:20 –> 02:07] Dr. Ravi Kumar: Welcome to the Doctor Kumar Discovery Podcast. I’m Doctor Ravi Kumar. Today, we’re doing a deep dive on glyphosate. It is the most widely used herbicide in the world, and there’s a very good chance you have it inside your body right now. Now you might be asking yourself, why is a doctor doing an episode on a weed killer? And that’s a fair question, and here’s the answer. Glyphosate is sprayed on nearly every conventional farm field in America. It’s applied directly to crops that become your food, your cereal, your oatmeal, your bread, your cooking oil. And because of that, it has been detected in human urine, in blood, and in breast milk. This is not a chemical you can choose to opt out of just by not buying a bottle of it at your local garden center. It is likely already inside your body, and that is why we’re talking about it today.

[02:07 –> 02:41] Dr. Ravi Kumar: And the reason it’s especially relevant right now is that in February 2026, the American president signed an executive order invoking the Defense Production Act. It’s a wartime statute that expands domestic glyphosate production and declares it a matter of national security. So our government is not just allowing this compound in our food supply, they’re actively pushing to make more of it. So that’s the situation.

[02:41 –> 03:13] Dr. Ravi Kumar: I do have an opinion on this, and I will share it, but my main goal here is to give you the actual facts. What glyphosate is, how it works, how it ends up in your body, and what the science really says about whether you should be concerned or not. I want you to walk away from this episode informed so that you can make your own decisions. Because right now, most people have heard the word glyphosate but have no idea what it actually is or what it does. And your doctor probably has not spent a lot of time on this either. So let’s fix that with this episode.

[03:13 –> 03:50] Dr. Ravi Kumar: But before we do, I just want to give you a quick disclaimer. I’m a medical doctor, but I’m not your doctor. This show is for informational purposes only. It’s not meant to diagnose or treat any medical condition, and it’s definitely not giving you any recommendations. My goal is to give you information and knowledge, because knowledge is power. And the more empowered you are, the more capable you are to take care of your own health. Also, this show is separate from my role as assistant professor at UNC. So let’s start from the very beginning. What actually is glyphosate?

[03:50 –> 04:34] Dr. Ravi Kumar: Chemically, it’s a compound called N-phosphomethylglycine, which is an organic molecule that works by blocking a specific enzyme in plants called EPSP synthase. That enzyme is part of what’s called the shikimate pathway, which plants use to produce three essential amino acids: tryptophan, tyrosine, and phenylalanine. If you block that pathway, the plant can’t make those amino acids, and it dies. Now here’s the argument that was used for decades to say that glyphosate is safe for humans: the shikimate pathway doesn’t exist in human cells. We don’t have that enzyme, so the logic was spray it on a plant, it kills a plant, but it doesn’t affect human biology. Except it’s not that simple. And this is where things get really interesting and a little bit worrisome. The shikimate pathway does exist in your body, in the bacteria that live in your gut.

[04:34 –> 05:02] Dr. Ravi Kumar: And your gut microbiome, the trillions of bacteria living in your intestines, are arguably one of the most important systems in your body. It regulates your immune system, produces vitamins, makes neurotransmitter precursors, and keeps inflammation in check. When glyphosate comes in and disrupts the shikimate pathway in those bacteria, you have a problem. Okay, so I want you to remember that little fact, because we’ll come back to it later when we start talking about the biological effects of glyphosate.

[05:02 –> 05:47] Dr. Ravi Kumar: Now here’s something I always say. If you want to understand the problem, start with the history. Ask, how did we get here? Because the answer to that question usually explains a lot about why things are the way they are right now. And with glyphosate, the history is genuinely fascinating and a little strange. So let’s start there. Glyphosate was not invented as a weed killer, not originally at least. The first synthesis of glyphosate actually dates back to 1950 at a small Swiss pharmaceutical company.

[05:47 –> 06:14] Dr. Ravi Kumar: A chemist made it when he was trying to develop a new antibiotic. It didn’t work as intended, and the research was shelved, literally put in a chemical storeroom and the data never published. Then in 1961, another company patented the compound in the US, not as an herbicide, but as a descaling and chelating agent. Chelating means it binds to metals. They used glyphosate to clean mineral deposits out of industrial boilers and pipes.

[06:14 –> 06:43] Dr. Ravi Kumar: So fast forward to 1970, a chemist was working on water softening compounds and discovered that glyphosate had potential herbicidal properties. His company patented glyphosate as an herbicide in 1971 and brought it to market in 1974. For the first decade or so, there was very little use in food systems. Glyphosate was nonselective, meaning it kills everything that’s green. So farmers couldn’t spray it on growing crops without killing those too.

[06:43 –> 07:46] Dr. Ravi Kumar: That changed in 1996, when glyphosate-ready, genetically modified crops were introduced. These were soybeans, corn, cotton, canola that had been engineered with a bacterial gene making them resistant to glyphosate. Now, farmers could spray glyphosate directly on growing crops to kill the weeds, and the crops would survive. That was a game changer, and its use exploded. By 2007, glyphosate was the most heavily used agricultural chemical in US history. By 2012, the US alone was using approximately 280 to 290 million pounds of glyphosate. And today, in 2023’s data, 91% of corn, 95% of soybeans, and 94% of cotton grown in the United States are from strains genetically modified to tolerate glyphosate.

[07:46 –> 08:23] Dr. Ravi Kumar: Now, there are two main routes by which glyphosate ends up in the food supply. Route one is obvious. It’s sprayed on GMO crops during the growing season to control weeds. The crop absorbs some of it, and when you eat the grains from that crop, trace amounts of glyphosate enter your body. Route two is one that most people don’t know about, and it’s actually more concerning in terms of food residue levels. It’s called pre-harvest desiccation. This is the practice of spraying glyphosate directly onto non-GMO crops like oats, wheat, barley, and lentils right before harvest, not to kill weeds, but to kill the crop itself. When the crop dies, it dries out faster and more uniformly, making harvest easier and cheaper.

[08:23 –> 08:56] Dr. Ravi Kumar: The problem is that when you spray glyphosate onto grain that is about to be harvested and eaten, the residues are much higher than when it’s used earlier in the growing season. This is a common practice in growing oats. And that’s why glyphosate residues show up in much higher concentrations in oat-based products. The Environmental Working Group has conducted multiple rounds of testing on oat-based foods. In their first major testing round, glyphosate was found in nearly all conventional oat-based products that they tested, including popular breakfast cereals.

[08:56 –> 09:26] Dr. Ravi Kumar: And the FDA’s own testing, which notably excludes oats and wheat, found glyphosate on about 63% of corn samples and 67% of soybean samples. Even organic products are not completely immune, due to drift of glyphosate from neighboring fields or shared processing facilities. So the takeaway here is that glyphosate is in your food right now, and most people have no idea.

[09:26 –> 10:04] Dr. Ravi Kumar: Hey, guys. I created this podcast because there’s too much confusion out there. There’s too much noise, too many conflicting messages about our health. My goal was simple when I made this podcast. I wanna cut through all of that and give you information that you can actually use. If that resonates with you, here’s how you can help. Leave a rating and a review on Apple Podcasts. Share an episode that resonated with you with someone else that you care about, and that’s how this show grows. That’s how we reach more people who are searching for answers. Thanks for being a part of this, and I appreciate your help.

[10:04 –> 10:42] Dr. Ravi Kumar: Okay, the next question should be, is glyphosate actually bad for our bodies? Because both independent labs and government labs confirm that it is actually in our food supply. Now, this is the part I really want to spend time on because this is where the conversation gets both nuanced, and frankly, in my opinion, alarming. Let’s start with the regulatory picture, because you need this context. The US EPA currently classifies glyphosate as quote not likely to be carcinogenic to humans. And the European Food Safety Authority and European Chemicals Agency just renewed glyphosate’s approval in Europe for another ten years in late 2023, though that decision is being challenged in courts.

[10:42 –> 11:19] Dr. Ravi Kumar: On the other side, in 2015, the International Agency for Research on Cancer, which is the Cancer Agency of the World Health Organization, classified glyphosate as Group 2A, probably carcinogenic to humans. That classification was primarily based on evidence linking glyphosate exposure to non-Hodgkin lymphoma in humans, and on sufficient evidence of it being a carcinogen in animal studies. So we have a split at the regulatory level. Some are saying it’s probably not bad for you, and others are saying it’s probably bad for you. How do we make sense of this? Well, let’s look at what the actual science says. Let’s start with cancer.

[11:19 –> 12:17] Dr. Ravi Kumar: A 2023 systematic review published by researchers from UC Berkeley analyzed glyphosate using 10 key characteristics of carcinogen hazard identification. They found strong evidence for five of those 10 characteristics, with particularly strong and consistent findings for genotoxicity and endocrine disruption. The authors concluded that their findings “strengthen the mechanistic evidence that glyphosate is a probable human carcinogen.” And then, a 2023 pooled study analyzing three case control studies found a statistically significant association between glyphosate herbicide exposure and non-Hodgkin lymphoma, including a subtype called hairy cell leukemia. And in June 2025, the most comprehensive independent long-term animal study ever conducted on glyphosate was published.

[12:17 –> 13:06] Dr. Ravi Kumar: This is the Global Glyphosate Study led by the Ramazzini Institute in Italy, and it involved research teams from multiple countries. The study exposed rats to glyphosate from prenatal development through their lives, and at doses that fall within what European regulators currently consider safe. They found evidence of multiple types of cancers, genotoxicity, which again is DNA damage, endocrine disruption, and microbiome harm at these safe dose levels. The authors state that the results “demonstrate tumorigenic potential of glyphosate and glyphosate-based products at dose levels considered safe.”

[13:06 –> 13:32] Dr. Ravi Kumar: Over 100,000 people have sued the manufacturer of glyphosate, claiming that it caused their non-Hodgkin’s lymphoma. And well over $10,000,000,000 in settlements have been paid. The company continues to maintain that glyphosate is safe, but the fact that a corporation pays that kind of money to settle cases is worth noting. Next, let’s talk about the microbiome. This is, in my view, one of the most important and underappreciated concerns. I mentioned earlier that while human cells don’t have the shikimate pathway, our gut bacteria do.

[13:32 –> 14:26] Dr. Ravi Kumar: And research published in peer-reviewed journals has documented that glyphosate disrupts the composition of the gut microbiota. A 2023 study found dose-dependent alterations in gut microbiome composition following glyphosate exposure at doses within the currently accepted safe limits. And the formulated product, with its added surfactants, showed even more pronounced effects than glyphosate alone. Because the shikimate pathway is disrupted in gut bacteria exposed to glyphosate, there’s a downstream effect on the production of tryptophan, tyrosine, and phenylalanine, the very amino acids that the gut microbiome helps supply to your body, and tryptophan is a precursor to serotonin. If your gut bacteria are not producing adequate tryptophan because glyphosate is inhibiting that pathway, you could have downstream effects on mood, cognition, and brain function.

[14:26 –> 14:59] Dr. Ravi Kumar: That’s speculative at the human population level, but it’s mechanistically plausible. Additionally, the surfactants in glyphosate formulations have been shown to cause gut inflammation and may disrupt the gut lining independent of glyphosate itself. Now to be fair, not every study points in the same direction. A 2017 animal study found limited microbiome effects even at doses up to fifty times the European accepted daily intake. But that’s one study against a growing body of evidence pointing the other way.

[14:59 –> 15:32] Dr. Ravi Kumar: Science is rarely black and white, especially without large, well-controlled human clinical trials. But what I can tell you is that the weight of evidence across multiple independent research groups, multiple animal models, and multiple methodologies consistently point towards glyphosate disrupting the microbiome. Now here’s something else that genuinely concerns me, especially as someone who thinks about kids’ health. Glyphosate has been identified as a potential endocrine disruptor. That means it may interfere with hormone signaling in the body.

[15:32 –> 16:18] Dr. Ravi Kumar: And in kids, that’s a major deal. Hormones are the chemical messengers that control growth, development, puberty, metabolism, mood, and reproduction. When you’re talking about children eating conventional oatmeal and sandwich bread every single day during the years when their bodies are literally being built, the idea that there is a compound in that food that may be interfering with hormone signaling should give every parent pause. Studies in human cell lines have found endocrine-disrupting effects at low doses, including interference with estrogen and androgen signaling. And the Global Glyphosate Study, the most comprehensive independent animal study ever done on this compound, confirmed endocrine-disrupting effects at doses currently considered safe by regulators.

[16:18 –> 16:59] Dr. Ravi Kumar: Okay, moving on, glyphosate also disrupts the liver. A 2023 prospective cohort study found associations between glyphosate metabolite levels in the urine of children and markers of liver damage indicative of nonalcoholic fatty liver disease and metabolic syndrome. Other studies have also associated glyphosate with nonalcoholic fatty liver disease, which strengthens the suspicion that glyphosate is not good for our livers. There are also neurological concerns with glyphosate. A 2021 large nationwide study found statistically significant associations between glyphosate exposure and increased risk of ALS.

[16:59 –> 17:46] Dr. Ravi Kumar: And other research has investigated links between glyphosate and anxiety-like behaviors in animal models, potentially mediated through microbiome alterations. So when you put all this together, the cancer associations, the microbiome disruption, the endocrine effects, the liver effects, the litigation, it’s hard to look at the totality of this evidence and conclude that glyphosate is doing nothing to our biology. The weight of independent science suggests it’s probably affecting us, and probably not in a good way, which is exactly why it’s so jarring to watch the United States government invoke a wartime production statute to make more of it.

[17:46 –> 18:26] Dr. Ravi Kumar: So what am I actually talking about? Well, let me put this in context because this is literally happening right now. On February 18, 2026, the President of the United States signed an executive order invoking the Defense Production Act, a wartime production statute, to boost domestic glyphosate production. The order declares glyphosate a matter of national security and states that there is no direct one-for-one chemical alternative and directs the Secretary of Agriculture to ensure adequate supply. The order also extends liability protections to the sole US producer of this chemical. And this is coming from the same administration that brought the Make America Healthy Again movement. Robert F. Kennedy Jr., who ran on a platform of getting glyphosate out of American agriculture, is now the Health and Human Services Secretary.

[18:26 –> 19:27] Dr. Ravi Kumar: And he publicly backed the executive order, framing it as a supply chain issue, arguing that if glyphosate disappeared overnight, crop yields would collapse and food prices would surge. And honestly, that’s probably true in the short term. American agriculture has become deeply, structurally dependent on this compound, and meaningful change would take a lot of time. But this has created a fascinating fracture. MAHA advocates, the very people who rallied around Kennedy, are calling it a betrayal. Meanwhile, the only US producer of glyphosate was reportedly considering ending production due to ongoing legal liability. This executive order essentially gave that company legal cover to just keep going.

[19:27 –> 19:43] Dr. Ravi Kumar: This is a case study in how economic and agricultural policy, national security framing, and public health concerns can end up in direct conflict. And in those types of conflicts, historically, the public loses. Hey everybody. I’m building an app called ShareMyTrial.com, and I need your help. The idea for this app is simple. What if we could crowdsource health solutions?

[19:43 –> 20:09] Dr. Ravi Kumar: Real people sharing what actually worked for their health problem, and a community that validates what has worked on a larger scale. That discovery that someone made about their migraines, their sleep, their energy, it shouldn’t stay locked in their heads. It should reach you. If you’re interested in helping me make this happen, go to ShareMyTrial.com and sign up to be a beta tester. And together, we can build something that democratizes health discovery. Cheers.

[20:09 –> 21:05] Dr. Ravi Kumar: So I want to be honest with you about where I stand on this. I try to present evidence fairly. I’m a scientist and a physician, and I take that responsibility very seriously. But I also believe in common sense. So let me share a thought experiment with you that might help you make sense of this whole situation. Imagine you went to a team of chemists and researchers who developed glyphosate for agricultural use and were actively trying to push for its commercial use in our food supply. And then, you make two sandwiches, exactly the same sandwich, but you spray glyphosate on one of them, just a little bit, and per regulators, it shouldn’t be harmful. You put both on the table, tell the chemist which one was sprayed with glyphosate, and say, pick one and feed it to your kids. I’m pretty sure they’d pick the one without the glyphosate on it.

[21:05 –> 22:05] Dr. Ravi Kumar: Common sense, right? Because no one wants chemicals on their food. Now imagine this. Every loaf of bread made with grain sprayed with glyphosate had a label on the package that says this bread has glyphosate in it. Do you think anyone would buy that bread? I don’t think so, but right now, pretty much all non-organic bread has glyphosate in it. And we’re buying it, and we’re eating it. It’s an invisible, non-disclosed risk. When something like glyphosate becomes normalized, when it’s invisible, when it’s microscopically embedded in your food at levels we’re told are safe, and when it happens at an industrial scale over fifty years, we stop being able to perceive risk. We get acclimated to it, and the people profiting from its use have every incentive to make sure the conversation stays complicated and the regulatory threshold stays loose.

[22:05 –> 23:06] Dr. Ravi Kumar: The science right now is genuinely conflicted at the regulatory level. There are real scientists at the EPA and EFSA who have looked at this and concluded that glyphosate is safe at current exposure levels. But there are also real independent scientists at the Ramazzini Institute, King’s College of London, and UC Berkeley who are finding biological harm at those same “quote unquote safe” dose levels in animal models, in cell studies, and in human epidemiological data. I personally am not comfortable having this compound in my family’s food. That’s my own position, not because of irrational fear, but because when a compound has multiple plausible mechanisms of harm, like genotoxicity, endocrine disruption, microbiome disruption, metal chelation, and we have biological evidence of harm at doses we’re currently exposed to, the burden of proof should be on demonstrating safety, not on us proving that it’s dangerous.

[23:06 –> 23:50] Dr. Ravi Kumar: Okay, so what do you do with this information? Well, first you have to decide whether having glyphosate in your food bothers you or not. If it doesn’t, then fine. Just go on living your life. But if you don’t want glyphosate in your food, let me give you some practical steps for avoiding it. First, buy organic for your highest risk foods. The USDA certified organic standard prohibits the use of glyphosate. Your highest risk conventional foods are oats, wheat, soy, corn, lentils, and chickpeas. Switching to organic oatmeal and organic grains is the single highest-impact dietary change for reducing glyphosate exposure. Second, look for glyphosate residue free certification.

[23:50 –> 24:38] Dr. Ravi Kumar: This is a certification program run by The Detox Project that tests products and certifies them as glyphosate residue free. This is actually more stringent than organic certification for this specific concern, and you’ll start seeing it on more labels. Third, reduce your processed food consumption. The vast majority of conventional processed food products contain corn, soy, canola, and wheat, all of which are heavily exposed to glyphosate. Whole foods from organic sources dramatically reduce your exposure. Fourth, filter your water. Glyphosate has been detected in some water sources. Reverse osmosis, which is what I use at my house, effectively filters out glyphosate. And fifth, diversify your diet. Don’t rely heavily on any single grain or crop.

[24:38 –> 25:24] Dr. Ravi Kumar: Will these steps eliminate your exposure entirely? Probably not. But they will reduce it meaningfully. And the precautionary argument here is strong. This is a compound with plausible biological harm, a controversial safety record, and a regulatory history that has been significantly influenced by industry. In my opinion, making intentional choices to reduce exposure to glyphosate is rational and reasonable. Okay, so that wraps it up. I hope that was informative for you, and I hope you have a better idea of what glyphosate is and what it might do to your biology. The main thing I want you to take away from today is this: that you deserve to know what’s in your food.

[25:24 –> 26:03] Dr. Ravi Kumar: As always, my goal on this podcast is to give you the information your doctor probably doesn’t have the time to give you or research for themselves. I want you to question everything, and I want you to understand the evidence, and I want you to form your own views and make informed decisions based on good, solid, unbiased information. If this episode was useful to you, share it with someone. Leave a comment. Leave a review. It genuinely helps this show reach more people. So until next time, stay curious, stay skeptical, and stay healthy. Cheers.