Bitter orange
Citrus × aurantiumThe first citrus to reach Europe was not the sweet orange but the bitter orange, brought to al-Andalus by the Arabs; the streets of Seville are still lined with thousands of bitter orange trees.
What is Bitter orange?
Bitter orange (Citrus × aurantium) is a plant of the Rutaceae family. Traditions that use it: Anatolia and the Mediterranean, Asia and Siberia. Part used: peel, fruit, flowers.
What is Bitter orange used for?
Traditional use: A garden and street tree from Antalya to Hatay. Scientific evidence: limited. Bitter orange is added to “fat-burning” weight-loss supplements as a source of synephrine.
Is Bitter orange safe?
Safety label: caution. Safe as fruit and jam. Synephrine weight-loss supplements, especially with caffeine, have been linked to palpitations, raised blood pressure and, rarely, stroke; people with heart disease or high blood pressure and pregnant women should avoid them. Peel oil can make skin sensitive to sun. Like grapefruit, the juice can raise blood levels of some drugs.
Traditional use
A garden and street tree from Antalya to Hatay. The peel is made into jam and the sour juice replaces lemon in salads and cooking. Orange blossom water is distilled from the flowers.
Chinese medicine uses the dried unripe fruit (zhi shi) for indigestion. Fruit from the trees of Seville becomes marmalade in Britain, and neroli oil from the flowers is a basic note of perfumery.
In nature
Mix-up risk
Very like the sweet orange, but the peel is rougher and the flesh seedy and very sour. Bergamot is a different citrus.
Preparation
The peel is made into jam or candied; dried peel is steeped in a cup of water for 10 minutes.
What science says
Bitter orange is added to “fat-burning” weight-loss supplements as a source of synephrine. A 2022 systematic review found that synephrine alone did not clearly raise heart rate or blood pressure, but its effect on weight loss was small and uncertain. Palpitations and strokes have been reported with products combining it with caffeine and other stimulants. Use of the peel for indigestion rests on tradition.
Safety
Safe as fruit and jam. Synephrine weight-loss supplements, especially with caffeine, have been linked to palpitations, raised blood pressure and, rarely, stroke; people with heart disease or high blood pressure and pregnant women should avoid them. Peel oil can make skin sensitive to sun. Like grapefruit, the juice can raise blood levels of some drugs.
Drug interactions
| Medicine or substance | Why it matters |
|---|---|
| Caffeine and stimulants | With synephrine, heart rate and blood pressure may rise. |
| Blood pressure medicines and MAO inhibitors | Synephrine may raise blood pressure; it can be dangerous with MAO inhibitors. |
| Some calcium channel blockers and statins | Like grapefruit, Seville orange juice blocks the gut enzyme CYP3A4 and can raise levels of drugs such as felodipine. |
This list is not complete. If you take regular medication, ask your pharmacist or doctor before trying Bitter orange.
Read more
Similar plants
Sources
- NCCIHUS National Center for Complementary and Integrative Health: use and safety summary
- ResearchThe Safety and Efficacy of Citrus aurantium (Bitter Orange) Extracts and p-Synephrine: A Systematic Review and Meta-Analysis (Nutrients 2022)
- ResearchCitrus aurantium L. Active Constituents, Biological Effects and Extraction Methods: An Updated Review (Molecules 2021)
- BookBaytop T. Türkiye’de Bitkiler ile Tedavi: Geçmişte ve Bugün. 3. baskı (yay. haz. F. Baytop Günergun). Ankara: Nobel Tıp Kitabevleri; 2021.
- Botanical recordKew Plants of the World Online: Citrus × aurantium
- Titles of research sources are summarised in Turkish on the Turkish page; links open the original English publications.
Written by Edanaz Tınmazlar · Last reviewed: · Türkçe