What Happens if You Accidentally Eat Green Potatoes?

December 24, 2025 •

4 min read

According to the National Capital Poison Center, the green color on potatoes, caused by chlorophyll, is a warning sign that the potentially toxic compound solanine may also be present. If you accidentally eat green potatoes, you could be ingesting this harmful neurotoxin, which can lead to adverse health effects.

Quick Summary

Eating green potatoes can cause solanine toxicity, leading to symptoms like nausea, vomiting, and headache. Discarding heavily green or bitter-tasting potatoes is the safest course of action, as cooking does not destroy the toxin.

Key Points

Solanine is the Toxin: The green color is a warning sign of the presence of solanine, a natural neurotoxin, not the green chlorophyll itself.
Peel and Trim: For minor greening, peeling the potato and cutting away all green parts, along with any sprouts, can make it safe to eat.
Cooking Does Not Help: High heat from cooking methods like boiling or baking does not destroy or remove solanine.
Bitter Taste is a Red Flag: If a potato tastes bitter after cooking, it likely contains high levels of solanine and should be discarded immediately.
Store Properly: Prevent greening by storing potatoes in a cool, dark, and well-ventilated place away from light and onions.
Discard Heavily Green Potatoes: Potatoes that are extensively green should be discarded, as the toxin may be deeply concentrated.
Symptoms Can be Delayed: Gastrointestinal and neurological symptoms from solanine poisoning can take several hours to appear.

The Science Behind Green Potatoes

When potatoes are exposed to sunlight or artificial light during storage, they undergo a natural process that triggers the production of two distinct compounds: chlorophyll and glycoalkaloids. The chlorophyll is responsible for the visible green pigment, which is harmless. However, the light exposure also stimulates the production of glycoalkaloids, primarily solanine, which is a natural neurotoxin that serves as a defense mechanism for the potato plant. The presence of green is the potato's built-in warning system that solanine levels might be elevated.

What are Glycoalkaloids?

Glycoalkaloids are bitter-tasting, nitrogen-containing compounds found throughout the potato plant, including the leaves, flowers, and sprouts. In healthy, properly stored potatoes, these levels are low and harmless. However, as the potato turns green, the concentration of solanine increases significantly, particularly in the skin and just beneath it.

Symptoms of Solanine Poisoning

Most people who accidentally consume a small amount of a slightly green potato are unlikely to experience serious harm. The bitter taste is often enough to deter consumption before a toxic dose is reached. However, if a larger quantity of a potato with high solanine levels is eaten, symptoms of poisoning can occur. The onset of symptoms is typically delayed by 8 to 10 hours and may last for a few days.

Common symptoms of mild to moderate solanine poisoning include:

Nausea and vomiting
Abdominal pain and diarrhea
Headache
Burning sensation in the mouth or throat
Dizziness

In rare and extreme cases, severe poisoning can lead to more serious neurological effects and complications, though fatalities are exceptionally rare.

What to Do if You Feel Sick

For mild symptoms, most people recover at home without special treatment. However, if symptoms are severe, persistent, or if you are concerned, you should contact a poison control center or seek medical attention. For a child, who is more susceptible due to their smaller body mass, medical advice should be sought immediately.

Can You Salvage a Green Potato?

Whether a green potato can be salvaged depends on the extent of the greening and the presence of a bitter taste. Since the highest concentration of solanine is in the skin and the area just beneath it, peeling and trimming can be effective for minor green spots.

Here is a step-by-step guide for salvaging a lightly green potato:

Thoroughly inspect the potato for any green areas or sprouts ('eyes').
Use a peeler or knife to completely remove all of the skin.
Cut out any visible green spots or sprouts, going about a quarter of an inch deeper into the flesh to ensure all toxin-containing tissue is removed.
Cook the trimmed potato. While cooking does not destroy solanine, it is still necessary for digestion and food safety.
After cooking, taste a small, isolated piece. If it tastes bitter or causes a tingling sensation in your mouth, discard the entire potato.

Why You Shouldn't Cook a Heavily Green Potato

If a potato is extensively green, it's best to throw it away entirely. The solanine may have penetrated deeper into the flesh, and trimming might not be sufficient. Furthermore, if the greening is accompanied by sprouting or a bitter flavor, the toxin levels are likely too high to be safe. It is a common misconception that cooking will destroy the toxin; cooking does not eliminate solanine.

Comparison Table: How to Handle Green Potatoes


Feature	Slightly Green Potato (Minor Spots)	Heavily Green Potato (Widespread Color)
Safety	Potentially safe to consume after proper trimming.	Unsafe for consumption.
Recommended Action	Cut off the green portions, peel, and remove sprouts. If bitter, discard.	Discard immediately. Do not attempt to salvage.
Solanine Concentration	Elevated, but mostly concentrated in the skin and surface.	Likely high throughout the tuber, especially under the skin.
Indicator	Light exposure during storage.	Significant light exposure or prolonged improper storage.
Result of Consumption	Unlikely to cause illness if trimmed correctly.	High risk of gastrointestinal and neurological symptoms.

Prevention is the Best Cure

The most effective way to avoid accidentally eating green potatoes is to prevent them from turning green in the first place. Proper storage is crucial.

Store in a cool, dark place: Potatoes thrive in a cool, dark, and well-ventilated environment, like a pantry, root cellar, or cabinet.
Avoid light exposure: Direct or indirect light, even from a nearby window, will initiate the greening process.
Use opaque storage: Store potatoes in a paper bag, burlap sack, or an opaque container to block out light. Avoid storing them in clear plastic bags.
Don't refrigerate: Storing potatoes in the refrigerator can alter their flavor and texture, converting their starch into sugar.
Keep away from onions: Onions emit gases that can speed up potato sprouting. Store them separately to maximize shelf life.

Conclusion

In conclusion, while a small, isolated green spot on a potato can likely be safely trimmed away, extensive greening or a bitter taste indicates potentially dangerous levels of solanine. The green color is a critical warning sign that should not be ignored. Since cooking does not destroy the toxin, the safest course of action for a heavily green potato is to discard it. By storing potatoes correctly in a cool, dark place, you can prevent greening and ensure your meals are both delicious and safe.

For more detailed information on food safety and poisoning, consider visiting the Poison Control website.

Frequently Asked Questions

The green substance on potatoes is chlorophyll, which is harmless. However, its presence indicates that the potato has been exposed to light, which also triggers the production of the toxic compound solanine.

Yes, if the green spot is small and localized, you can safely consume the rest of the potato. Simply peel the skin and cut away the green portion, removing any sprouts as well.

Yes, if you eat a potato with high levels of solanine, you can experience symptoms such as nausea, vomiting, abdominal pain, and headaches. The severity depends on the amount consumed and the concentration of the toxin.

Peeling can significantly reduce solanine levels, as the toxin is most concentrated in and just under the skin. However, if the potato is heavily green or tastes bitter, the toxin may have penetrated deeper, and it should be discarded.

No, cooking methods such as boiling, baking, and frying do not effectively destroy solanine. The only way to remove it is by physically cutting out the affected parts.

A bitter taste is a strong indicator of high solanine levels. If you notice this, stop eating the potato immediately and discard it to avoid illness.

Store potatoes in a cool, dark, and dry place like a pantry or cupboard. Using a paper bag or basket helps block light and allows for good air circulation.

Solanine is naturally present in all potatoes, but typically at low, safe levels. It becomes a concern when its concentration increases due to light exposure, physical damage, or sprouting.