Citrus Bergamot Side Effects: The 2 Problems 13 Trials Recorded

Quick Answer: We read 13 human trials of oral citrus bergamot extract or juice. Only two of them named a specific side effect in the bergamot group: moderate heartburn (“gastric pyrosis”) in 3 of 35 people taking a bergamot polyphenol formulation for 90 days, none of whom stopped, and dizziness that made 2 of 48 older adults withdraw from a 12-week trial of a bergamot-based formulation. Five other trials reported no adverse events or none related to the product, and six did not report adverse events in any text we could read. The phototoxic skin reactions, burns and blisters that dominate most “bergamot side effects” lists come from bergamot essential oil on the skin, a different product. The honest limit: a 2026 meta-analysis of nine trials found that adverse-event reporting “was limited” and that the short-duration evidence “is insufficient to establish safety”. An advertisement for a bergamot product appears near the end of this page.

Search for bergamot side effects and you will find long lists: sun sensitivity, skin burns, muscle cramps, drug interactions, low blood sugar. Some of those come from the essential oil, some from grapefruit research applied by analogy, and few come from people who swallowed a bergamot supplement in a trial. This page separates the three. Every number below is from a trial or study we read, and where a trial did not report something, we say so rather than fill the gap.

What the oral bergamot trials actually recorded

We searched PubMed for randomized and clinical trials of bergamot and kept the ones in which people took bergamot by mouth, as an extract, a polyphenol fraction or a juice-based drink, either alone or as the formulation’s base. We left out aromatherapy studies (inhaled oil) and multi-ingredient products where bergamot was one of several actives, such as combinations with plant sterols, artichoke or red yeast rice, because a side effect in those cannot be pinned on bergamot. That left 13 trials.

Counted that way: 2 trials named a side effect, 5 reported none or none related to the product, and 6 did not report adverse events in any text we could read. The six silent trials are not evidence of harm, but they are not evidence of safety either. A trial that does not report adverse events tells you nothing about them.

The two named problems, in proportion

Heartburn. In Capomolla 2019, three people out of 35 on the bergamot formulation had what the authors called moderate gastric pyrosis, the medical term for heartburn. The authors note that this was similar to “our previous report” on the same research group’s bergamot fraction. Nobody stopped because of it, and the placebo group had its own complaints (headache, constipation). Heartburn is the one side effect that appears in a bergamot group in more than one report from this group.

Dizziness. In Cai 2017, two of 48 older adults on CitriCholess left the trial because of dizziness. CitriCholess is described as a Citrus bergamia extracts-based formulation, and the trial was run in adults around 65 with high blood lipids. Two cases in one trial do not establish that bergamot causes dizziness, but it is the only side effect in this set of trials that made anyone stop.

What the 2026 meta-analysis says about safety

A 2026 systematic review and meta-analysis by Chambari and colleagues pooled nine randomized trials with 615 participants. On benefits it found modest improvements in cholesterol, blood sugar and blood pressure, with certainty that “ranged from low to very low for all outcomes”. On safety it was blunt:

• “When considering safety, adverse‐event reporting was limited.”
• “The available short‐duration evidence is insufficient to establish safety.”
• On liver enzymes, changes “were generally nonsignificant”, but “subgroup analyzes suggested a slight increase in AST among participants with obesity and in studies using capsule formulations”. The authors call this “hypothesis‐generating” because few studies contributed.

AST is one of the liver enzymes on a routine blood panel. A small, uncertain signal in a subgroup is not a liver warning, but it is a reason to mention the supplement to whoever orders your blood tests. For context, LiverTox, the US National Library of Medicine’s database of drug and supplement liver injury, has no entry for bergamot (searched 12 October 2026).

Where most “bergamot side effects” come from: the essential oil

Bergamot essential oil is pressed from the rind and used in perfume, aromatherapy and Earl Grey flavouring. It is a different product from the polyphenol extract made from the juice, and it carries a well-documented hazard the extract trials never measured: phototoxicity.

The oil contains furocoumarins, “primarily bergapten (5-methoxypsoralen [5-MOP])”, which make skin react to ultraviolet light. Case reports describe what happens when the oil meets the sun:

• Two people developed “localized and disseminated bullous phototoxic skin reactions” 48 to 72 hours after exposure to bergamot aromatherapy oil followed by UV light. One had never touched the oil; she was exposed to it evaporated in a sauna and then used a tanning bed (Kaddu 2001).
• Undiluted bergamot oil on the skin followed by sunlight caused a phototoxic reaction that left lasting hyperpigmentation (2007 case report).
• “Berloque dermatitis”, streaky dark marks where perfume containing bergamot was applied before sun exposure, was mistaken for child abuse in a 9-year-old girl (2002).
• The same reaction has been reported with the colognes “Florida Water” and “Kananga Water” (2002).

The authors of the 2001 report note that bergamot oil was widely used in cosmetics “but was restricted or banned in most countries because of certain adverse effects”. None of this has been reported in the oral extract trials above. If a side-effects list leads with sunburn, blisters or skin discoloration, it is describing the oil.

Drug interactions: what is known and what is assumed

The grapefruit question

Grapefruit juice raises blood levels of some drugs by blocking the CYP3A4 enzyme in the gut, and a 2006 crossover study showed the furanocoumarins in the juice are what do it: removing about 99% of them from grapefruit juice removed the effect on the blood-pressure drug felodipine. Bergamot juice contains furanocoumarins too. A 2008 analysis of Calabrian bergamot juice measured bergapten at 9.0 mg/L and bergamottin at 18.2 mg/L.

That is where the evidence stops. We found no human study testing whether a bergamot extract changes CYP3A4 drug levels, and the amount of furanocoumarin left in a given extract depends on how it was made and is not stated on supplement labels. So “bergamot interacts like grapefruit” is a reasonable caution, not a finding.

The one measured drug-level result

The only trial we found that measured drug levels alongside bergamot is Bruno 2017: in 28 outpatients taking antipsychotics, 500 mg a day of bergamot polyphenolic fraction for 60 days did not significantly change serum concentrations of clozapine, olanzapine, risperidone, 9-hydroxyrisperidone or quetiapine. That is one dose, one drug class and a small sample.

Statins

Bergamot is often taken alongside a statin. Gliozzi 2013 gave 1,000 mg of bergamot fraction plus 10 mg rosuvastatin to 15 patients for 30 days and reported a larger cholesterol drop than rosuvastatin alone; it did not report statin blood levels. If you take a statin or any prescription drug, the practical step is to tell the prescriber, because the combination is designed to lower the same numbers your doctor is tracking.

Who should be more careful

• Anyone using bergamot essential oil on the skin, especially before sun or tanning-bed exposure. The case reports above are all of this kind.
• People on prescription medicines, because there are no interaction trials for most drugs, and grapefruit’s mechanism is plausible but untested for bergamot extracts.
• People prone to heartburn, the one side effect seen in a bergamot group in this research group’s trials.
• Pregnant or breastfeeding women, not because of a recorded harm but because none of the trials we read included them.
• Anyone planning long-term use: the longest trials ran six months (Toth 2015).

Frequently Asked Questions

What are the side effects of citrus bergamot?

In 13 human trials of oral bergamot extract or juice, two named side effects in the bergamot group: moderate heartburn in 3 of 35 people (none stopped) and dizziness that led 2 of 48 older adults to withdraw. Five trials recorded no adverse events or none related to the product, and six did not report them.

Does citrus bergamot cause sun sensitivity?

Phototoxic skin reactions are documented for bergamot essential oil applied to the skin, because it contains bergapten. We found no report of phototoxicity in the oral extract trials.

Is citrus bergamot bad for the liver?

The trials we read reported no clinically relevant liver changes. A 2026 meta-analysis found liver enzyme changes “generally nonsignificant” but a slight AST rise in some subgroups, which it called hypothesis-generating. LiverTox has no bergamot entry.

Can you take bergamot with a statin?

One trial gave bergamot fraction with rosuvastatin for 30 days and reported a larger cholesterol drop, without measuring statin levels. There are no interaction trials for most statins, so tell your prescriber before combining them.

Does bergamot interact with medications like grapefruit?

Bergamot juice contains the same class of compounds (furanocoumarins) that cause grapefruit’s interactions, but we found no human study testing a bergamot extract on CYP3A4 drug levels. One small trial found no significant change in antipsychotic blood levels at 500 mg a day.

Is bergamot in Earl Grey tea the same as a bergamot supplement?

No. Earl Grey is flavoured with bergamot essential oil from the rind. Supplements use extracts or polyphenol fractions from the juice, which is what the trials tested.

The Bottom Line

The oral bergamot trials record very little: heartburn in a few people in one trial and dizziness that made two older adults stop in another, against several trials that recorded nothing and several that did not report at all. The serious-sounding side effects online belong mostly to the essential oil on sunlit skin, and the drug-interaction warnings are borrowed from grapefruit rather than measured for bergamot extracts. The real gap is time and reporting: trials ran six months at most, and a 2026 review judged the evidence “insufficient to establish safety”. Of the 13 trials in our table, 2 named a side effect. For the cholesterol evidence itself, see our page on citrus bergamot for cholesterol.

Sources

1. Capomolla AS, Janda E, Paone S, et al. Atherogenic Index Reduction and Weight Loss in Metabolic Syndrome Patients Treated with A Novel Pectin-Enriched Formulation of Bergamot Polyphenols. Nutrients, 2019. PMID 31167512; full text PMC6627641. 52 subjects, BPE-C low n = 17 (650 mg), high n = 18 (1,300 mg), placebo n = 17, 90 days; “moderate gastric pyrosis in BPE-C low (n = 2) and BPE-C high (n = 1) groups”; placebo headache (n = 2) and constipation (n = 1); “none of the patients taking BPE-C interrupted the treatment”. Checked 12 October 2026.
2. Cai Y, Xing G, Shen T, et al. Effects of 12-week supplementation of Citrus bergamia extracts-based formulation CitriCholess on cholesterol and body weight in older adults with dyslipidemia. Lipids Health Dis, 2017. PMID 29273027; full text PMC5741859. 98 adults, CitriCholess n = 48, placebo n = 50, 12 weeks; “Two subjects in the CitriCholess group withdrew from the study due to the symptom of dizziness.” Checked 12 October 2026.
3. Toth PP, Patti AM, Nikolic D, et al. Bergamot Reduces Plasma Lipids, Atherogenic Small Dense LDL, and Subclinical Atherosclerosis in Subjects with Moderate Hypercholesterolemia: A 6 Months Prospective Study. Front Pharmacol, 2015. PMID 26779019; full text PMC4702027. 80 subjects, 150 mg flavonoids a day, 6 months; “None of them had to discontinue the supplementation and no adverse events were recorded.” Checked 12 October 2026.
4. Bruno A, Pandolfo G, Crucitti M, et al. Low-Dose of Bergamot-Derived Polyphenolic Fraction (BPF) Did Not Improve Metabolic Parameters in Second Generation Antipsychotics-Treated Patients: Results from a 60-days Open-Label Study. Front Pharmacol, 2017. PMID 28443024; full text PMC5387046. 28 outpatients, 500 mg a day, 60 days; “no adverse effects were recorded in our sample during the 60-days treatment period”; serum concentrations of clozapine, olanzapine, risperidone, 9-hydroxyrisperidone and quetiapine “were not affected significantly by administration of BPF”. Checked 12 October 2026.
5. Rondanelli M, Peroni G, Riva A, et al. Bergamot phytosome improved visceral fat and plasma lipid profiles in overweight and obese class I subject with mild hypercholesterolemia: A randomized placebo controlled trial. Phytother Res, 2021. PMID 33188552; full text PMC8246838. 64 participants (33 bergamot, 31 placebo), 500 mg, 12 weeks; “no relevant adverse effects recorded”. Checked 12 October 2026.
6. Maggiolo G, Aldigeri R, Savini C, et al. Chronic consumption of a bergamot-based beverage does not affect glucose, lipid and inflammatory biomarkers of cardiometabolic risk in healthy subjects: a randomised controlled intervention study. Food Funct, 2024. PMID 38767145. 45 healthy subjects, 400 mL a day; “BBB was well tolerated and no adverse events were recorded.” Checked 12 October 2026.
7. Yu X, Amone F, Zaccaria V, et al. Lipid Metabolism Modulation by a Flavonoid-Standardized Citrus Bergamia Extract in an Asian Population. J Exp Pharmacol, 2026. PMID 42592560; full text PMC13464414. 108 adults, 375 mg (150 mg flavonoids) a day, 4 months; six participants (three per group) discontinued “due to personal reasons not related to product use”; “no adverse effects on hepatic or renal function were detected in either group”. Checked 12 October 2026.
8. Mollace V, Sacco I, Janda E, et al. Hypolipemic and hypoglycaemic activity of bergamot polyphenols: from animal models to human studies. Fitoterapia, 2011. PMID 21056640. 237 patients, 30 days; adverse events not reported in the abstract. Checked 12 October 2026.
9. Gliozzi M, Walker R, Muscoli S, et al. Bergamot polyphenolic fraction enhances rosuvastatin-induced effect on LDL-cholesterol, LOX-1 expression and protein kinase B phosphorylation in patients with hyperlipidemia. Int J Cardiol, 2013. PMID 24239156. 77 patients; BPF 1,000 mg a day alone (n = 15) or plus rosuvastatin 10 mg (n = 15), 30 days; adverse events and statin levels not reported in the abstract. Checked 12 October 2026.
10. Bruno A, Pandolfo G, Crucitti M, et al. Metabolic outcomes of bergamot polyphenolic fraction administration in patients treated with second-generation antipsychotics: a pilot study. J Nutr Biochem, 2017. PMID 27846426. 15 outpatients, 1,000 mg a day, 30 days; abstract: “effective and safe”, no event counts. Checked 12 October 2026.
11. Bruno A, Pandolfo G, Crucitti M, et al. Bergamot Polyphenolic Fraction Supplementation Improves Cognitive Functioning in Schizophrenia: Data From an 8-Week, Open-Label Pilot Study. J Clin Psychopharmacol, 2017. PMID 28591067. 20 outpatients, 1,000 mg a day, 8 weeks; adverse events not reported in the abstract. Checked 12 October 2026.
12. Mollace V, Scicchitano M, Paone S, et al. Hypoglycemic and Hypolipemic Effects of a New Lecithin Formulation of Bergamot Polyphenolic Fraction: A Double Blind, Randomized, Placebo-Controlled Study. Endocr Metab Immune Disord Drug Targets, 2019. PMID 30501605. 60 patients; adverse events not reported in the abstract. Checked 12 October 2026.
13. Pierdomenico M, Cicero AFG, Veronesi M, et al. Effect of Citrus bergamia extract on lipid profile: A combined in vitro and human study. Phytother Res, 2023. PMID 37312672. 50 subjects, Brumex 400 mg or placebo, 12 weeks; adverse events not reported in the abstract. Checked 12 October 2026.
14. Chambari M, Mardani H, Roshandel M, et al. Bergamot (Citrus bergamia) Supplementation and Cardiovascular Disease Risk Factors: A Systematic Review and Dose-Response Meta-Analysis. Food Sci Nutr, 2026. PMID 42746152; full text PMC13575982. Nine RCTs, 615 participants; certainty “ranged from low to very low for all outcomes”; “adverse‐event reporting was limited”; “The available short‐duration evidence is insufficient to establish safety”; “a slight increase in AST among participants with obesity and in studies using capsule formulations”, “hypothesis‐generating”. Checked 12 October 2026.
15. Kaddu S, Kerl H, Wolf P. Accidental bullous phototoxic reactions to bergamot aromatherapy oil. J Am Acad Dermatol, 2001. PMID 11511848. Furocoumarins, “primarily bergapten (5-methoxypsoralen [5-MOP])”; two patients with bullous reactions 48 to 72 hours after exposure and UV; oil “restricted or banned in most countries” in cosmetics. Checked 12 October 2026.
16. Knott E, Hofmann H. Purely natural: phototoxic dermatitis (in German). MMW Fortschr Med, 2007. PMID 17619401. Undiluted bergamot oil plus sunlight; persisting hyperpigmentation. Checked 12 October 2026.
17. Gruson LM, Chang MW. Berloque dermatitis mimicking child abuse. Arch Pediatr Adolesc Med, 2002. PMID 12413335. 9-year-old girl. Checked 12 October 2026.
18. Wang L, Sterling B, Don P. Berloque dermatitis induced by “Florida water”. Cutis, 2002. PMID 12184670. Colognes “Florida Water” and “Kananga Water”. Checked 12 October 2026.
19. Paine MF, Widmer WW, Hart HL, et al. A furanocoumarin-free grapefruit juice establishes furanocoumarins as the mediators of the grapefruit juice-felodipine interaction. Am J Clin Nutr, 2006. PMID 16685052. 18 volunteers; furanocoumarins removed “approximately 99%”; effect on felodipine removed. Checked 12 October 2026.
20. Gardana C, Nalin F, Simonetti P. Evaluation of flavonoids and furanocoumarins from Citrus bergamia (Bergamot) juice and identification of new compounds. Molecules, 2008. PMID 18830151. Bergapten 9.0 mg/L and bergamottin 18.2 mg/L in bergamot juice. Checked 12 October 2026.
21. LiverTox, National Library of Medicine (NCBI Bookshelf). LiverTox; a search of the NCBI Bookshelf for bergamot within LiverTox returned no entry. 13 trials counted in our table: 2 named a side effect, 5 reported none or none related, 6 not reported. Checked 12 October 2026.