Quince Drug Interactions, Uses, Effectiveness, Safety & More

Quince (Cydonia oblonga) is a fruit-bearing tree in the rose family, related to apples and pears. The fruit is yellow, fragrant, and very tart, so it is usually cooked into jams, jellies, syrups, and desserts rather than eaten raw. The tree grows in parts of Asia, the Middle East, the Mediterranean region, and other temperate areas.

People have used quince fruit, seeds, and leaves in traditional medicine for hundreds of years. It is most often linked with soothing the stomach and digestive tract, calming a sore throat, and softening or protecting the skin. Today you may find quince as fresh fruit, syrups, teas, and supplement forms such as extracts or capsules.

Quince contains plant compounds such as antioxidants (including polyphenols and flavonoids), vitamin C, and fiber like pectin. The seeds release a slippery, gel-like mucilage when soaked in water. This mucilage is thought to coat and soothe the throat and digestive lining, which may help explain its traditional use for reflux and irritation.

Laboratory studies suggest quince extracts may have antioxidant and antimicrobial activity, and some animal research points to possible anti-inflammatory effects. Keep in mind that these findings are early and based mostly on test-tube or animal studies, so they may not translate to the same benefits in people.

Quince eaten as a cooked food is generally considered safe for most people. Concentrated supplements, seed products, and extracts have not been studied as carefully, so their long-term safety is unknown.

One important caution: quince seeds, like the seeds of apples and other related fruits, contain compounds that can release small amounts of cyanide if crushed and eaten in large quantities. Do not chew or grind raw seeds. People with allergies to fruits in the rose family (such as apples, pears, peaches) should be cautious.

For pregnancy and breastfeeding, quince as a normal food is likely fine, but there is not enough reliable information on concentrated quince extracts or seed products. To be safe, avoid supplement-strength quince during these times unless your doctor approves. Always check with a pharmacist or doctor before starting any new supplement.

When eaten as food, quince rarely causes problems. Possible side effects, especially with large amounts or concentrated products, may include mild stomach upset, constipation (the fruit is high in tannins and fiber), or an allergic reaction in people sensitive to related fruits.

Serious effects are uncommon, but eating crushed quince seeds in large amounts could in theory cause cyanide-related toxicity. Stop using quince and seek medical care if you have signs of an allergic reaction such as rash, swelling, or trouble breathing.

There is no standardized or proven dose for quince supplements. The right amount depends on the product, the part of the plant used, and how it is prepared, which varies a lot between brands.

If you choose to use a quince product, follow the directions on the label and do not exceed the suggested amount. Avoid eating raw or crushed seeds. Because doses are not well established, it is best to check with a pharmacist or doctor before using quince supplements, especially if you take medications or have a health condition.