Is the green part of a potato poisonous? Understanding Solanine

January 11, 2026 •

3 min read

Potatoes contain a natural toxin called solanine, a glycoalkaloid, as a defense mechanism. When exposed to light, potatoes may turn green due to the production of chlorophyll, often indicating increased levels of solanine. Knowing if the green part of a potato is poisonous is important.

Quick Summary

The green parts of a potato signal higher levels of the toxin, solanine. Light exposure triggers chlorophyll and solanine production. High doses can cause gastrointestinal and neurological problems. Removing or discarding affected potatoes is recommended to ensure safety.

Key Points

Green Indicates Toxicity: Green potatoes have higher solanine levels, a toxic compound.
Solanine is Harmful: High solanine levels can cause gastrointestinal and neurological symptoms.
Cooking Doesn't Eliminate Solanine: Heat does not fully destroy solanine; peeling and trimming are essential.
Peel and Trim: For minor greening, peel and remove all green sections and sprouts to reduce risk.
Discard Heavily Green Potatoes: Throw away heavily green or bitter-tasting potatoes.
Store Properly: Store potatoes in a cool, dark place to prevent solanine production.

The Science Behind Green Potatoes

Potatoes, tomatoes, and eggplants belong to the nightshade family, Solanaceae. These plants naturally produce glycoalkaloids, bitter nitrogen-containing compounds. Solanine is one of the most common glycoalkaloids in potatoes. Under normal conditions, solanine levels are low and mainly in the leaves, stems, and sprouts. However, light exposure triggers photosynthesis. This causes the potato to produce chlorophyll, a harmless green pigment.

Unfortunately, the same conditions that cause chlorophyll production also increase solanine. The green color indicates elevated solanine. While chlorophyll itself is not toxic, its presence is a warning. Solanine levels are highest in the green skin and sprouts. Small green spots might not be a problem, but extensively green or bitter-tasting potatoes should be discarded.

How to Handle Green Potatoes

Inspect Potatoes: Check for green discoloration before cooking, especially on lighter-skinned varieties. Scratch darker potatoes to check for green underneath.
Look for Sprouts: Sprouts, or "eyes," have the highest solanine concentration. Remove them completely.
Check for Flavor: Solanine tastes bitter. Discard bitter-tasting potatoes, regardless of greening.
Proper Storage: Store potatoes in a cool, dark, and dry place. Light exposure causes chlorophyll and solanine production.

Health Risks of Consuming Solanine

Small amounts of solanine are harmless for most, but higher levels can cause solanine poisoning. Symptoms are mainly gastrointestinal and neurological. Children and individuals with lower body weight are more vulnerable. Serious cases are rare, but can occur with large amounts of highly toxic potatoes. The bitter taste is a natural defense.

Symptoms of Solanine Poisoning

Nausea and vomiting
Diarrhea
Abdominal pain
Headaches
Drowsiness or fatigue
Burning sensation in the mouth or throat

Comparison: Safe vs. Unsafe Potato Preparation


Feature	Safe Potato Preparation	Unsafe Potato Handling
Appearance	No green spots; firm texture; few or no sprouts.	Extensive greening, especially under the skin; many sprouts or "eyes"; bitter taste.
Storage	Store in a cool, dark, and well-ventilated area.	Store in bright, warm areas, near windows or other light sources.
Preparation	Peel potatoes thoroughly and remove any visible green spots and sprouts.	Cooking a very green potato without peeling or removing sprouts.
Cooking	Cooking reduces solanine levels, but not entirely. Always follow proper trimming precautions.	Believing that cooking will completely destroy the solanine toxin, which it does not.
Action	When in doubt, trim away small green areas or discard the potato if heavily affected.	Consuming potatoes with extensive greening, even after cooking.

Can You Salvage a Green Potato?

For potatoes with minor greening, peeling and trimming usually remove most solanine. Removing the peel reduces the risk. However, heavily green or bitter potatoes should be discarded. The risk is not worth the potential issues, especially when the potato has a clear warning sign. Cooking does not fully eliminate the toxin, so proper trimming is the best safety measure.

Conclusion

The green part of a potato poses a health risk due to the solanine. The green color, from chlorophyll, indicates increased solanine production. Peeling and trimming small green areas can be effective. Discard extensively green or bitter potatoes. Store potatoes in a cool, dark place to minimize solanine exposure and ensure food safety. If solanine poisoning is suspected, seek medical advice immediately. Consult webPOISONCONTROL for more information.

Frequently Asked Questions

No, cooking does not completely eliminate solanine. While cooking may reduce the amount, it is not a foolproof method. The safest approach is to peel, trim any green spots, or discard green potatoes.

Solanine is a natural toxin in potatoes, acting as a defense against pests. Its levels rise when exposed to light, causing the potato to turn green.

Symptoms include nausea, vomiting, diarrhea, abdominal pain, and headaches. In severe cases, neurological symptoms may occur.

Yes, if the green spot is small, you can cut it out and peel the rest of the potato. Most of the solanine is concentrated in the green skin.

Store potatoes in a cool, dark, and dry place, such as a pantry or cellar. Keep them in a breathable bag, away from light to prevent the production of chlorophyll and solanine.

No, solanine is naturally present throughout the potato, but in higher concentrations in the green parts, sprouts, and skin, especially after light exposure.

A bitter taste indicates high solanine levels, regardless of greening. Discard any potato that tastes bitter immediately.