Why Can't You Eat Sprouted Potatoes? The Toxin Hidden in Your Pantry

October 6, 2025 •

3 min read

An estimated 11% of all food waste in the average American household comes from fresh vegetables, a significant portion of which is potatoes that have gone bad. The primary reason for this discard is often sprouting, leading many to wonder, "why can't you eat sprouted potatoes?" The answer lies in the accumulation of toxic compounds that occur naturally as the potato ages and sprouts.

Quick Summary

Sprouted potatoes contain elevated levels of natural toxins called glycoalkaloids, like solanine and chaconine, which can cause gastrointestinal and neurological symptoms. Their toxicity level increases with the length of the sprouts and any associated greening. It is often safest to discard badly sprouted or green potatoes entirely.

Key Points

Toxins Develop in Sprouts: Potatoes produce glycoalkaloids like solanine in their sprouts, which can cause illness.
Green Means Toxic: Green skin on a potato indicates high levels of solanine, making it unsafe to eat.
Peeling is Not Enough: Cooking does not destroy glycoalkaloids, and even peeling may not remove all toxins if levels are very high.
Discard if Soft or Shriveled: If a sprouted potato is soft, mushy, or wrinkled, it should be discarded as toxin levels are likely elevated throughout.
Prevent with Proper Storage: Store potatoes in a cool, dark, and dry place away from onions to prevent sprouting and prolong freshness.
When in Doubt, Throw it Out: If a potato is heavily sprouted, very green, or tastes bitter, it is safest to discard it completely.

The Hidden Danger: Glycoalkaloids Explained

When a potato begins to sprout, it's not simply a sign of age but an indication of a significant biochemical change. As a member of the nightshade family, potatoes naturally contain toxic compounds called glycoalkaloids, primarily solanine and chaconine. While these compounds exist in low, non-harmful concentrations in fresh potatoes, they increase dramatically when the potato is exposed to light or warm temperatures, causing it to sprout. This concentration is highest in the sprouts, the eyes, and any areas of green skin. In high enough doses, these toxins can pose a serious health risk, which is precisely why you can't eat sprouted potatoes without caution.

Symptoms of Solanine Poisoning

Consuming a potato with a high level of glycoalkaloids can lead to a condition known as solanine poisoning. The symptoms can range from mild to severe, typically appearing within a few hours to a day after ingestion. For most people, it may cause uncomfortable but manageable issues. However, the risk increases with the amount consumed and for more sensitive individuals, like children.

Mild Symptoms

Nausea and vomiting
Abdominal cramps and pain
Diarrhea
Headaches and dizziness

Severe Symptoms (rare but serious)

Hallucinations
Paralysis
Fever
Low blood pressure
Rapid pulse

How to Assess if a Sprouted Potato is Safe

Deciding whether to salvage a sprouted potato or throw it away depends on its overall condition. It's a risk-reward calculation based on several factors. A good rule of thumb is to inspect the potato carefully for signs of extensive decay and high toxin concentration. Here's a quick guide:

Firmness: Is the potato still firm to the touch? If it's soft, mushy, or shriveled, the sprouting process has likely consumed too many nutrients and increased toxin levels throughout the tuber.
Sprout Size: Small, newly formed sprouts can be carefully removed with a paring knife or vegetable peeler. However, if the sprouts are long or extensive, the toxin concentration is likely too high to be entirely removed.
Green Patches: Any green discoloration on the potato's skin is a tell-tale sign of high solanine levels. While chlorophyll itself is harmless, its presence indicates that solanine has also developed. Peel away all green parts completely or discard the potato if the greening is widespread.
Taste Test: A high concentration of glycoalkaloids gives the potato a bitter taste. If, after peeling and cooking, the potato tastes bitter, it should be discarded.

Comparison: Sprouted vs. Unsprouted Potatoes


Feature	Fresh, Unsprouted Potato	Sprouted or Green Potato
Texture	Firm and smooth	Soft, wrinkled, and possibly shriveled
Appearance	Uniform skin color, no sprouts	Visible sprouts (eyes), possible green skin
Toxin Levels	Negligible, safe for consumption	High concentration of glycoalkaloids (solanine, chaconine)
Edibility	Safe to eat (raw or cooked)	Only salvageable if sprouts and green areas are minimal and removed
Flavor	Starchy, mild, classic potato flavor	Unpleasantly bitter, especially near sprouts/green parts

Proper Storage Prevents Sprouting

To avoid this food safety dilemma, proper storage is crucial. Preventing potatoes from sprouting in the first place is the best course of action. Following these steps can significantly extend the shelf life of your potatoes and keep them safe for consumption:

Keep them cool and dark: Store potatoes in a cool, dark, and well-ventilated area, like a pantry or cellar. Exposure to light and warmth accelerates the production of chlorophyll and solanine.
Avoid onions: Do not store potatoes near onions. Onions release ethylene gas, which can hasten the sprouting process in potatoes.
Use breathable containers: Store potatoes in a paper bag, a mesh bag, or a wire basket, as this allows air to circulate around them and prevents moisture buildup.
Check regularly: Periodically inspect your potato stash and use any older potatoes first. Discard any that are soft, shriveled, or extensively green or sprouted.

The Final Verdict

While a slightly sprouted potato with minimal damage might be salvageable with careful removal of sprouts and green skin, it is a risky endeavor. The presence of toxins like solanine makes it clear why you can't eat sprouted potatoes without concern. For peace of mind and to avoid potential illness, particularly with extensively sprouted or green potatoes, the safest and most recommended practice is to simply throw them out. Your health is worth more than a few dollars' worth of potatoes. When in doubt, as the experts at Poison Control recommend, throw it out.

Frequently Asked Questions

Accidentally eating a very small, firm sprouted potato that has been properly peeled with the eyes removed is unlikely to cause serious harm. The concentration of toxins may be too low to induce a reaction. However, any bitterness indicates higher toxin levels, and the potato should be discarded immediately.

Yes, if the potato is still firm and has only small, new sprouts, you can use a knife or peeler to completely cut out the sprouts and the surrounding 'eyes'. However, this method is only safe for firm potatoes with minimal sprouting. If the potato is soft, shriveled, or has extensive sprouting, it should be discarded.

Green skin on a potato indicates the presence of chlorophyll, which also signals a higher concentration of the toxin solanine. If the green area is small, you can peel it away entirely and deeply. However, if the potato is extensively green or tastes bitter, it's best to throw it out to avoid potential solanine poisoning.

No, cooking methods like boiling, baking, and frying do not effectively destroy glycoalkaloids like solanine. While deep frying at very high temperatures might reduce some toxins, it is not a reliable method for making a toxic potato safe. The safest bet is to remove the affected parts or discard the potato entirely.

To prevent sprouting, store potatoes in a cool, dark, and well-ventilated space like a pantry. Keeping them away from sunlight, heat, and other produce, especially onions, will significantly slow the sprouting process.

While the exact toxic dose can vary, some studies suggest that as little as 1 mg of solanine per kilogram of body weight can cause symptoms, and 3 to 6 mg per kilogram could be fatal, though fatalities are extremely rare. The risk increases with higher concentrations found in green or extensively sprouted potatoes.

Yes, extensively sprouted potatoes are not necessarily useless. The sprouts can be cut from the potato and planted in the ground to grow new potato plants. This is a great way to repurpose potatoes that are no longer safe for consumption.