Glyphosate in Oats: What You Need to Know

Oats are about as wholesome as food gets. They're simple, cheap, filling, and they make up a large share of every bag of our All Day Granola. So it may be a surprise to learn that one of the most common herbicides in the world often shows up in oats - Glyphosate.

Many farmers spray it on the crop just before harvest to dry it out, and residue can stay on the grain.

That discovery changed how we buy oats. We discovered in our research where oats come from and how people have eaten them for centuries, how glyphosate entered the picture, what testing has found, and what we look for instead.

A short history of oats

While wheat and barley were domesticated thousands of years earlier, oats began as a weed growing among those crops. They earned their place in the cool, rainy lands of northern Europe, where wheat struggled and oats thrived.

They became the backbone of Scottish cooking, so much so that Samuel Johnson's 1755 dictionary famously defined oats as a grain that in England is given to horses, but in Scotland supports the people. For centuries, oats fed Scotland's farmers, fishermen, and soldiers. It is often said that oats "stick to your bones", or in otherwords, they can keep you full, especially when paired with other whole foods!

Traditional oat dishes around the world

It may seem strange to us now, but long before oats became a sweet breakfast, they were everyday savory food, often paired with fish, meat, or dairy to make a filling, balanced meal.

How oat processing changed

For most of history, oats were dried in a kiln, then ground between millstones into coarse oatmeal or cracked by hand. It was slow, and the meal could go rancid quickly. Over about a century, industrial milling transformed oats into the fast, shelf-stable food we know today.

• 1850s: German immigrant Ferdinand Schumacher began grinding oats in his Akron, Ohio, store with a hand mill, at a time when most Americans considered oats horse feed.
• 1870s: Schumacher patented a cutting machine that chopped oats into pieces, the steel-cut oats that replaced coarse stone-ground meal. Soon after, he began rolling oats flat, which cut cooking time. Steam was later added to the process.
• 1877: Quaker Oats became the first registered trademark for a breakfast cereal.
• 1922: Quick oats arrived, rolled thinner to cook in minutes.
• 1966: Instant oatmeal followed, precooked and rolled thinner still.

Through it all, the grain itself stayed much the same. The pace kept accelerating: faster milling, faster cooking, and eventually faster harvesting, which brings us to glyphosate. In this fast paced society we live in today, we need to remember that often faster is not better, and sometimes, the old ways are best. (Maybe more blogs on this subject to come!!)

Oats 101

Every kind of oat starts as the same whole grain, called a groat. The differences come from how it's cut, steamed, and pressed.

What about gluten?

Oats don't naturally contain gluten, but they're usually grown, harvested, and milled alongside wheat and barley, so cross-contact is common. Oats labeled "gluten-free" are grown and handled to keep that contact low and are tested to meet the FDA's gluten-free limit.

We use certified gluten-free, organic, sprouted oats. Our kitchen also handles wheat, though, so we don't label our granola gluten-free. If you need strictly gluten-free food, look for products made in a dedicated facility.

Why glyphosate ends up in oats

Glyphosate is the active ingredient in Roundup and the most widely used weed killer in the world. Most people know it from genetically engineered crops like corn and soy, which are bred to survive being sprayed. There are no genetically engineered oats, so you might expect oats to be off the hook.

They aren't, because of a practice called pre-harvest desiccation. In cool, wet growing regions, oats often ripen unevenly. Some farmers spray glyphosate shortly before harvest to kill the plants and dry them out all at once, so the combine can get into the field sooner. Because it's applied so close to harvest, residue can stay on the grain.

Where glyphosate came from

Glyphosate began as a lab curiosity. A Swiss chemist named Henri Martin first made it in 1950 while working for a pharmaceutical company, but found no medical use for it. In the 1960s, another company patented it as a chelating agent, a chemical that binds minerals, for cleaning and descaling pipes.

In 1970, Monsanto chemist John Franz, working on a program to develop water-softening compounds, discovered that glyphosate killed plants. Monsanto brought it to market as Roundup in 1974. Its U.S. patent protection ended in 2000, and cheap generic versions followed.

When spraying oats before harvest began

Glyphosate was first used on cereal crops right before harvest in the UK in 1980, originally to kill stubborn perennial weeds like couch grass at a time that wouldn't disrupt the next planting. Farmers soon noticed a side effect: it also dried the crop evenly. The practice spread through northern Europe and then worldwide, reaching North America's oat and wheat fields in a big way over the following decades.

Why glyphosate instead of natural drying?

Before glyphosate, farmers had other options, and many still use them. They could wait for the crop to dry down naturally in the field, or swath it: cut the stalks and lay them in rows to dry before combining. Those methods work, but they take time and depend on the weather.

Glyphosate won out in cool, wet growing regions for practical reasons:

• Speed. It can let farmers harvest as much as two weeks earlier, a big deal where autumn rain or early frost can ruin a crop.
• Even drying. Oats often ripen unevenly, and a uniformly dry field is easier to harvest and store.
• Weed control. It kills perennial weeds at the same time, setting up the next season.
• Cost. After the patent expired in 2000, generic glyphosate became inexpensive.

How oats get dry without glyphosate

If glyphosate's job is drying the crop evenly, how do glyphosate-free and sprouted oats get dry? It happens in two separate stages, and it helps to keep them apart: drying the grain in the field so it can be harvested and stored, and, for sprouted oats, drying the grain again after it's been sprouted.

Stage 1: In the field

Farmers who skip pre-harvest glyphosate use the same tools farmers relied on for generations, plus some modern equipment:

• Swathing. The crop is cut while still slightly green and laid in long rows, called swaths or windrows, on top of the stubble. Air moves underneath, and the plants finish ripening and drying evenly on the ground for several days before the combine picks them up. For oats, swathing can begin once the grain reaches the "medium dough" stage, firm but still dentable with a thumbnail, at under about 35% moisture.
• Straight cutting. The combine cuts and threshes standing oats in one pass once they've dried down naturally. It's the simplest method when the crop ripens evenly, but it means waiting on the weather.
• Harvesting a little damp, then drying with air. Oats can be harvested above safe storage moisture, then dried in a grain dryer or kept cool with bin aeration fans. Aeration alone can usually lower moisture by only 1 to 2%, so wetter grain goes through a heated dryer.

The target is dry, cool, stable grain. For oats, that's about 12.5% moisture or less for safe storage, unless the grain is kept below about 59°F.

When Canadian researchers compared pre-harvest glyphosate with direct cutting and swathing in oats, they found no significant yield differences across the moisture levels tested. Skipping glyphosate demands more planning and closer attention to the weather, and the harvest holds up.

Stage 2: How sprouted oats are made

Sprouted oats start as fully harvested, dried, and cleaned oats. Sprouting is basically waking the grain back up, then drying it again before it can grow into a plant. Commercial methods vary and are often kept private, but the core steps follow the same pattern as malting barley for brewing: steeping, germination, and kilning.

1. Clean and steep. The oats are cleaned and soaked in water so the grain absorbs enough moisture to come alive. In grain science, a moisture level of roughly 43 to 45% is what triggers germination.
2. Germinate. The damp grain rests in a controlled room with careful temperature, moisture, and airflow. Within a day or two, a tiny rootlet appears. A 2025 review found the most common research conditions were soaking for 12 hours at about 68°F, sprouting for 48 hours at about 77°F, and drying for 24 hours at about 122°F.
3. Dry. Once the sprout just emerges, the grain is dried quickly and gently, often in thin layers on screens or belt dryers, so every kernel dries at the same rate. This stops germination before the grain uses up too much of its stored energy.
4. Stabilize (kiln). Like all oats, sprouted oats need a heat treatment to switch off lipase, a natural enzyme that would otherwise break down the oats' oils and turn them rancid. Kilning also gives oats their familiar toasty, nutty flavor in place of a raw, hay-like taste.
5. Steam and roll. Finally, the groats are softened with steam and pressed flat into the rolled oats you'd recognize.

In sprouted oats, even drying is the work of controlled indoor equipment, where temperature, airflow, and timing are set precisely, batch after batch.

What testing has found

In 2018, the Environmental Working Group commissioned lab tests of popular oat foods. Glyphosate showed up in all but two of 45 samples made with conventional oats, and in 5 of 16 organic samples, at lower levels of 10 to 30 parts per billion. A second round found it in every one of 28 Cheerios and Quaker samples, with the highest at 2,837 parts per billion.

Public pressure has made a difference. After EWG's reports, several companies pledged to buy oats from farmers who don't use glyphosate as a drying agent, and EWG's later testing found levels dropping in some products.

Is it actually harmful?

Here is what some of the "experts" say (They can't seem to agree!!)

• The World Health Organization's cancer research agency classified glyphosate as a probable human carcinogen in 2015.
• The U.S. EPA classifies it as not likely to cause cancer at typical exposure levels, and allows up to 30 parts per million on oats. The oat foods EWG tested were well under that limit.
• EWG argues that limit is far too high and uses a much stricter benchmark of 160 parts per billion, based on daily lifetime exposure, especially for children.

We're not scientists, and we can't predict what future research will show. But the evidence of possible harm keeps growing (more on that below), and oats are something many families eat every single day. Small, repeated exposures add up.

What research says about children and people with weakened immune systems

Most glyphosate safety limits are set with healthy adults in mind. Researchers have started looking at the groups families worry about most.

Nearly everyone is exposed. In a CDC national survey of urine samples from people 6 and older, glyphosate was detected in about 81% of samples. Diet appears to be a main source.

Children may carry more. In a small 2020 study of four U.S. families, researchers found glyphosate in every participant, and children's levels averaged about five times higher than their parents'. Children eat more food for their body size than adults, which is one reason they're often considered more vulnerable to food residues.

Childhood exposure and liver and metabolic health. The longest-running study on children comes from UC Berkeley's CHAMACOS project, which followed 480 mothers and children in California's Salinas Valley from pregnancy to age 18. Children with higher levels of a glyphosate breakdown product in their urine had a higher risk of liver inflammation and metabolic syndrome at 18. Doubling that childhood level was linked to a 14% higher risk of elevated liver enzymes and a 55% higher risk of metabolic syndrome. Living near farm fields sprayed with glyphosate in early childhood was also linked to metabolic syndrome. The lead researcher noted that the glyphosate levels in the study were similar to those in the general U.S. population.

Cancer of the immune system. Non-Hodgkin lymphoma is a cancer of the white blood cells that make up part of the immune system. A 2019 meta-analysis found a 41% higher risk of non-Hodgkin lymphoma among people with the highest exposure to glyphosate-based herbicides. Those were mostly farmers and applicators handling the product directly, not people eating trace residues. Germany's risk assessment agency reviewed the analysis and said it didn't change their overall assessment.

The gut microbiome. Glyphosate kills plants by blocking a chemical pathway called the shikimate pathway. Humans don't have it, which is a main reason glyphosate was long considered safe for people. But many bacteria do, including some in our gut. One analysis predicted that 12 to 26% of common gut bacteria could be sensitive to glyphosate. Since the gut microbiome plays a large role in immune health, researchers say this deserves more study. So far, most of the evidence comes from lab and animal research.

Who wrote the research that called glyphosate safe?

There's another reason to read glyphosate's clean safety record with skepticism: some of it was shaped by the company that sold it.

In 2017, internal Monsanto emails were unsealed in lawsuits brought by people with non-Hodgkin lymphoma. In one, a Monsanto executive suggested company employees could write papers about glyphosate and have outside scientists publish them under their own names. The same documents showed a Monsanto executive recounting that a senior EPA official had offered to help stop a separate federal review of glyphosate. Monsanto denied ghostwriting.

In December 2025, the journal Regulatory Toxicology and Pharmacology retracted a landmark 2000 review that had concluded glyphosate posed no health risk to humans. The court documents showed Monsanto employees wrote it without being named as authors. That paper had been cited in more than 800 academic papers and dozens of government documents, including EPA assessments. The publisher has since opened investigations into two more glyphosate safety papers over similar concerns.

The retraction has its critics. A group of scientists has called for it to be reversed, and regulators say their decisions rest on many studies, not one review. But when a company helps write the science that regulators rely on, "no proven harm" means a lot less.

Where we stand

We don't think glyphosate belongs in our food. The open questions keep piling up: a probable-carcinogen rating from the World Health Organization's cancer agency, troubling findings in children, unresolved questions about the gut, and a safety record partly written by the manufacturer. For a food families eat every day, that's enough. We buy oats tested for glyphosate residue.

Families can lower their exposure quickly. In the same family study, switching to an organic diet lowered glyphosate levels in urine by about 70% within six days, for children and adults alike.

If you're caring for a young child, are pregnant, or have a weakened immune system, it's worth talking with your doctor about pesticide exposure and what changes make sense for you.

Why residue testing matters

You might think buying organic solves this. It helps a lot: certified organic farming doesn't allow synthetic herbicides like glyphosate. But organic doesn't guarantee zero. Spray can drift from neighboring fields, and oats can pick up residue in shared trucks, elevators, and mills. That's likely why EWG still found traces in about a third of the organic samples it tested.

The only way to know what's actually in the oats is to test them. That's why we look past the label to the lab report.

What we look for in oats

• Certified organic. The strongest starting point, since glyphosate isn't allowed in organic farming.
• Published residue testing. Look for brands that test their oats for glyphosate and share results, or carry a third-party "glyphosate residue free" certification.
• Clear sourcing. Brands that know their farms can tell you whether pre-harvest spraying is ruled out.
• Sprouted, if you can find it. Unrelated to glyphosate, sprouting gives oats a slightly sweeter flavor, and some people find them easier to digest.

The oats in our granola check every one of these boxes: organic, sprouted, gluten-free, and tested for glyphosate residue. They cost more than conventional oats, and they're worth it to us.

Recipe: Savory Herb and Cheddar Oats with a Jammy Egg

Savory oats have deep roots in Scottish cooking. Simmered in broth with sharp cheddar and greens, rolled oats turn creamy like risotto in about ten minutes. The egg and cheese add plenty of protein, so it can keep you full for hours!

Makes 1 bowl

• 1 egg
• 1/2 cup rolled oats
• 1 cup chicken or vegetable broth
  
• A scoop of grassfed beef collagen (optional)
• 1 tablespoon butter
• 1 small handful of spinach or kale, chopped
• 1/4 cup shredded sharp cheddar
• 1 green onion, thinly sliced
• A few fresh thyme leaves or chopped chives
• Salt and black pepper, to taste
• Hot sauce or chili crisp, (optional)
  

1. Cook the egg. Lower the egg into boiling water and cook for 6 1/2 minutes for a jammy yolk. Move it to a bowl of ice water, then peel.
2. Toast the oats. While the egg cooks, melt the butter in a small saucepan over medium heat. Add the oats and stir for 1 to 2 minutes, until they smell nutty.
3. Simmer. Pour in the broth, bring to a simmer, and cook for about 5 minutes, stirring often, until creamy.
4. Finish. Stir in the greens until wilted, then the cheddar until melted. Season with salt and plenty of pepper. Add a splash more broth if it's too thick.
5. Serve. Spoon into a bowl, halve the egg on top, and finish with green onion, herbs, and hot sauce if you like.

Make it uniquely YOU: Swap the cheddar for parmesan or feta, add leftover roasted vegetables, or top with sautéed mushrooms. There are no rules in recipes! 

Oats FAQ

Are organic oats glyphosate-free? Organic farming doesn't allow glyphosate, but drift and shared equipment can leave traces. Testing is the only way to know for sure.

Does washing or cooking oats remove glyphosate? Not reliably. Glyphosate is water-soluble, but residue on and in the grain isn't something you can count on rinsing away. Choosing tested oats is the more dependable route.

Are steel-cut oats healthier than rolled oats? They're nutritionally very similar. Steel-cut oats digest a little more slowly, but rolled oats are just as wholesome and far more versatile.

What are sprouted oats? Oats that are soaked until they just begin to sprout, then dried and rolled. They taste slightly sweeter, and some people find them easier to digest.

Are oats gluten-free? Naturally, yes, but cross-contact with wheat is common. If you need to avoid gluten, look for certified gluten-free oats made in a dedicated facility.