Is the Green Part of a Potato Toxic? What You Need to Know

December 23, 2025 •

4 min read

According to the National Capital Poison Center, green potatoes are not safe to eat due to potential toxicity. While the green color itself comes from harmless chlorophyll, it is a marker for the harmful toxin solanine, which can increase in concentration when exposed to light.

Quick Summary

Green potato areas signal a toxic compound called solanine, a natural defense mechanism produced under light exposure. For safety, peel away small green spots, but discard extensively green or bitter-tasting potatoes entirely.

Key Points

Indicator, not the Cause: The green color is harmless chlorophyll, but it indicates the presence of toxic solanine.
Peel and Trim: For minor green spots, peeling and cutting away the affected area is often sufficient to remove the toxin.
Bitter Taste is a Warning: A bitter taste is a reliable sign of high solanine levels, and any potato with this taste should not be eaten.
Discard Severely Green Potatoes: If a potato is very green or shows widespread discoloration, it is safest to discard the entire thing.
Proper Storage Prevents Greening: Store potatoes in a cool, dark, and dry place to prevent the production of solanine.
Cooking Does Not Remove Solanine: High heat does not effectively destroy the solanine toxin, making trimming or discarding the only safe options.

The Science Behind Green Potatoes and Toxicity

When a potato is exposed to sunlight or artificial light, it produces chlorophyll, the green pigment found in many plants. This process is called photosynthesis and is completely harmless. However, this same exposure to light also triggers the production of a toxic compound known as solanine, a type of glycoalkaloid. Solanine is a natural plant defense mechanism against pests and diseases. The green color serves as a visual indicator that the potato has been exposed to the conditions that increase solanine levels, which is a major food safety concern.

Solanine is a neurotoxin that can be harmful to humans in high doses. The highest concentration of solanine is typically found in the green skin, the sprouts or 'eyes,' and the flesh just beneath the peel. While solanine is always present in low levels in a potato, improper storage, damage, or prolonged light exposure can cause these levels to rise to potentially harmful amounts. This is why properly stored, non-green potatoes are safe to eat, while green or sprouted ones require careful handling.

Symptoms of Solanine Poisoning

Eating a potato with high levels of solanine can lead to various symptoms, primarily affecting the gastrointestinal and nervous systems. These symptoms can appear hours after consumption and may last for a few days. The severity depends on the amount of toxin ingested relative to body weight, with children being more susceptible to toxicity. Mild symptoms often resolve on their own, but severe cases require immediate medical attention.

Common symptoms of mild solanine poisoning include:

Nausea and vomiting
Diarrhea
Abdominal pain or cramping
Headache
Burning sensation in the throat

In very rare, extreme cases, more severe symptoms have been reported, such as:

Fever
Hallucinations
Loss of sensation
Paralysis
A slow pulse

How to Handle Different Green Potato Scenarios

Your course of action depends on the extent of the green discoloration. Use the bitter taste as your guide; if a cooked potato tastes bitter, it's best to discard it, regardless of the appearance.


Scenario	Recommended Action	Reason
Slight green tinge or a few small spots	Peel the potato and cut away all green and sprouted areas generously.	This removes most of the solanine, which is concentrated in the skin and green parts.
Extensive greening or large green areas	Discard the entire potato.	When greening is widespread, it is very difficult to remove all the solanine, making it unsafe to eat.
Small sprouts or 'eyes'	Cut out and remove all sprouts and surrounding flesh.	Sprouts and eyes have a higher concentration of solanine.
Potato has a bitter taste after cooking	Do not eat it; discard immediately.	This is a strong indicator of high solanine levels, and cooking does not remove the toxin.

Preventing Potatoes from Turning Green

The best way to manage greening is to prevent it from happening in the first place through proper storage. By taking a few simple precautions, you can ensure your potatoes remain safe and delicious for longer.

Tips for proper potato storage:

Keep them in the dark: Store potatoes in a cool, dark, and dry place, such as a pantry, basement, or cupboard, away from direct sunlight. Using a paper bag can also help shield them from light.
Avoid light exposure: Do not store potatoes on the countertop, where they can be exposed to natural or artificial light for extended periods.
Maintain proper temperature: Keep potatoes in a cool area. Storing them in the refrigerator is too cold and can cause the starch to turn to sugar, affecting flavor and texture.
Allow air circulation: Use a breathable container, like a basket or a mesh bag, instead of a sealed container that traps moisture and speeds up spoilage.
Don't store with onions: Onions emit gases that can speed up potato sprouting, so keep them separate.
Use in a timely manner: Purchase potatoes only as you need them to reduce storage time and the risk of spoilage.

Conclusion: When in Doubt, Throw It Out

Ultimately, while the green part of a potato itself (chlorophyll) is harmless, its presence is a crucial sign of the toxic compound solanine. Following safe handling procedures is essential to prevent potential poisoning. For minor greening, a thorough peel and trim is effective. However, if a potato is extensively green or has a bitter taste, it should be discarded immediately. Proper storage in a cool, dark place is the most effective way to prevent this issue. By staying vigilant and trusting your senses, you can continue to enjoy potatoes without worry. Healthline provides a great summary on green potatoes and solanine toxicity.

Frequently Asked Questions

No, cooking methods like boiling or baking do not effectively destroy solanine. The high heat does not degrade the toxin sufficiently to make it safe to eat.

Potatoes turn green when exposed to light, either sunlight or artificial light. This triggers the production of chlorophyll and the toxic compound solanine.

The highest concentrations of solanine are found in the green parts of the skin, the sprouts (or 'eyes'), and the flesh just beneath the peel.

Symptoms can include nausea, vomiting, diarrhea, stomach cramps, headaches, and a burning sensation in the mouth or throat. Severe cases are rare but possible.

Children are more susceptible to solanine toxicity. It is safest to be more cautious and either discard or thoroughly peel and trim any green areas on a potato before serving it to a child.

Store them in a cool, dark, and dry place, such as a pantry or cabinet, away from direct light. Using a paper bag can also help.

Potatoes with a high solanine content will have a distinct, bitter taste. This taste serves as a natural warning sign that the potato may be toxic.

For slight greening, yes. The non-green flesh of a potato with only minor greening is considered safe to eat, as long as you peel and trim generously. However, if the potato is extensively green or tastes bitter, the solanine may have spread further.