Sweet vs Bitter Orange Oil
Sweet and bitter orange oil compared: names and labels, what small inhalation trials found, the sunlight (phototoxicity) question, and the bitter orange supplement warnings.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read essential oil safety before you use anything on this page.
Safety first. Neither oil is for swallowing, and bitter orange is the one with the longer list of cautions. NCCIH says cases of serious medical events, including abnormal heart rhythms, heart attacks and strokes, have been reported in people who took bitter orange dietary supplements, although most of those products contained multiple ingredients, so it is unclear whether bitter orange was the cause. [1] That warning concerns supplements taken by mouth, not oil used for scent. If anyone swallows an essential oil, call Poison Help at 1-800-222-1222 (US), or 911 for collapse, a seizure or trouble breathing. See Poisoning: what to do first.
Names and labels
Botanical naming is a trap here. Trials of "sweet orange" name Citrus sinensis, [2] and trials of "bitter orange" name Citrus aurantium. [3] The GBIF taxonomic backbone currently lists Citrus sinensis (Mill.) Pers. as a synonym of Citrus × aurantium L. [4] [5] So the scientific names alone do not separate the two oils; the common names "sweet" and "bitter," and the label's botanical name and plant part, do. NCCIH describes the bitter orange tree as native to Southeast Asia, with fruit too sour to eat raw; the fruit, peel and essential oils are used in cooking, flavorings and perfumes. [1] The trial abstracts we read do not say which part of the tree the bitter orange oil came from, so check that on a label (how to read a label). Single-oil guide: Orange oil (sweet and bitter).Evidence, side by side
Every trial below tested inhaled oil and measured self-reported or physiological signs. Smell is hard to hide from a comparison group, so this is promising but limited evidence at best.| Oil | Trial | What the source found |
|---|---|---|
| Sweet orange | Labor, Brazil | In a single-blind randomized trial with 42 women per group, inhaling sweet orange oil reduced pain and anxiety scores compared with distilled water. [2] |
| Sweet orange | Healthy men, a stress test | Forty male volunteers inhaled sweet orange oil, tea tree oil or water; men in two of the three sweet orange groups showed no significant change in state anxiety during the stress test, unlike the control groups. [6] |
| Sweet orange vs lavender | Children's dental visits | In 150 children aged 8 to 12, both oils reduced anxiety, and only sweet orange reduced self-reported pain. [7] |
| Bitter orange | Pregnancy, Iran | In 68 pregnant women, inhaled bitter orange oil improved depression and anxiety scores compared with an odorless oil, and stress scores did not differ significantly in the further analysis. [8] |
| Bitter orange | Before coronary angiography, Iran | In 80 patients, anxiety scores and vital signs fell after inhaling the oil, and not after distilled water. [3] |
Proper evidence not found for a trial that compared sweet and bitter orange oil with each other (searched PubMed, NCCIH, EMA, 2026-10-23). NCCIH says it is unclear whether bitter orange oil helps anxiety or insomnia in aromatherapy, and that bitter orange has not been clearly shown to be helpful for any health-related purpose. [1] The authors of the sweet orange stress test say more studies are needed to find out the clinical relevance. [6]
Sunlight and skin
Some citrus oils contain compounds called furocoumarins that react with ultraviolet light on skin. A 1985 laboratory study found oxypeucedanin, a phototoxic compound, in large amounts in lime oil and bitter-orange oil as well as lemon oil. [9] A 2022 chemistry paper says such compounds are mainly in the non-volatile fraction of cold-pressed citrus oils. [10] For sweet orange oil, phototoxicity data are not described in the sources we read. That is a gap, not proof of safety. See phototoxicity: citrus oils and sunlight. NCCIH says bitter orange oil is generally well tolerated when used topically or in aromatherapy. [1] Both statements can be true: one is a general tolerance statement, the other is a laboratory finding about a specific compound.Frequently asked questions
Is sweet or bitter orange oil better for anxiety?
Not shown. Each has small inhaled-oil trials reporting lower anxiety scores, but we found no trial comparing the two. [2] [3]
Is bitter orange oil the same as the bitter orange in weight-loss supplements?
No. NCCIH's safety concerns are about dietary supplements that contain bitter orange extracts and synephrine, and it says bitter orange oil is generally well tolerated topically or in aromatherapy. [1]
Does orange oil make skin sensitive to the sun?
A 1985 study found a phototoxic compound in bitter-orange oil. [9] For sweet orange oil, it is not described in the sources we read, so follow label cautions and ask a pharmacist.
Are the two oils the same plant?
Per the GBIF backbone, the scientific name for sweet orange is a synonym of Citrus × aurantium, the name used for bitter orange, so check the common name and plant part on the label. [4] [5]
Can I swallow orange oil?
No advice to swallow essential oils is given here. Call Poison Help at 1-800-222-1222 (US) if someone has.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Other safety points
- Bitter orange supplements. In an FDA analysis cited by NCCIH, of 23 bitter orange products that stated a synephrine amount, only 5 were close to the label, and six products were adulterated with synthetic amines. [1] See product quality and contamination.
- Pregnancy and breastfeeding. NCCIH says it may not be safe to use bitter orange during pregnancy or breastfeeding. [1] That statement is about bitter orange generally; the pregnancy trial above is a hospital-style study, not advice. Ask the care team. See essential oils in pregnancy and breastfeeding.
- Medicines and heart conditions. NCCIH says to talk with a health care provider before using bitter orange if you take any medicine. [1]
- Children and swallowing. Poison Control says children have thin skin and immature livers, and notes orange oil is a common ingredient in furniture polishes and other wood care products, a common household source. [11]
- Pets, liver, kidney, older adults: not described for these oils in the sources we read.
References
- NCCIH, Bitter Orange (updated November 2024). Read 2026-10-23.
- Explore 2025: Effectiveness of aromatherapy with sweet orange oil in relieving pain and anxiety during labor. Read 2026-10-23.
- Chin J Integr Med 2021: Essential oil from Citrus aurantium alleviates anxiety of patients undergoing coronary angiography. Read 2026-10-23.
- GBIF Backbone, Citrus sinensis. Read 2026-10-23.
- GBIF Backbone, Citrus aurantium. Read 2026-10-23.
- J Altern Complement Med 2012: Effect of sweet orange aroma on experimental anxiety in humans. Read 2026-10-23.
- Journal of Caring Sciences 2021: Effect of aromatherapy on dental anxiety and pain in children undergoing local anesthetic administrations. Read 2026-10-23.
- Taiwan J Obstet Gynecol 2025: Aromatherapy with Citrus aurantium essential oil on depression, stress and anxiety in pregnant women. Read 2026-10-23.
- Arch Dermatol Res 1985: A study of the phototoxicity of lemon oil. Read 2026-10-23.
- Anal Bioanal Chem 2022: SFC-MS/MS of oxygen heterocyclic compounds in Citrus essential oils. Read 2026-10-23.
- Poison Control, Essential oils: Poisonous when misused. Read 2026-10-23.