Bitter Orange, Yohimbe and Other Stimulant Herbs: Heart and Blood Pressure Risks
Bitter orange (synephrine) and yohimbe supplements are sold for weight loss and energy. See what trials found, the heart and blood pressure reports, label problems and who should ask first.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Safety first. NCCIH says serious medical events, including abnormal heart rhythms, heart attacks and strokes, have been reported in people who took bitter orange products, but most products had several ingredients, so it is unclear what caused them. [1] For yohimbine, the main compound in yohimbe, NCCIH says it has been associated with irregular heartbeat, blood pressure problems, heart attacks and seizures. [2] In the US, call 911 for chest pain, fainting, signs of a stroke or a seizure. For a possible poisoning, Poison Help is 1-800-222-1222.
What these herbs are
Bitter orange is Citrus × aurantium L. (family Rutaceae). The fruit, peel and oils are used in cooking and flavoring, and it is also called Seville orange, sour orange and zhi shi. [3][1] Its fruit contains p-synephrine, which is structurally similar to ephedrine but acts differently in the body. [1] NCCIH says bitter orange is likely safe in amounts found in foods and that the oil is generally well tolerated on the skin or in aromatherapy; the worries are about supplements. [1] For the oil, see Essential Oils.Yohimbe is the bark of an evergreen tree from central and western Africa. NCCIH names it Pausinystalia yohimbe; GBIF lists the older spelling P. johimbe as a synonym of Corynanthe johimbe, so names vary by source. [2][4]
Traditional use
This is tradition, not proof. NCCIH says yohimbe bark has been used traditionally as an aphrodisiac and sexual performance enhancer. [2] NCCIH lists "zhi shi" among the common names of bitter orange, and says the fruit, peel and oils are used in cooking. [1]What research shows
| Use | What the source found | Strength of evidence | Who and what was studied |
|---|---|---|---|
| Bitter orange for weight loss | A 2022 meta-analysis of 18 placebo-controlled trials found no evidence that synephrine helps weight loss. [5] NCCIH says studies were small and often tested combination products. [1] | No good evidence of benefit | Adults; synephrine or bitter orange extracts |
| Bitter orange and blood pressure | The meta-analysis found blood pressure rose significantly after prolonged use and that synephrine tends to raise blood pressure and heart rate. [5] NCCIH calls the evidence inconclusive, since some studies show a rise and others do not. [1] | Mixed; possible harm | Adults in trials |
| Bitter orange for athletic performance | Results were inconsistent and most studies did not show a benefit. [1] | Insufficient evidence | Small studies, with or without caffeine |
| Yohimbe for any condition | NCCIH says there is not enough research to say it helps any condition, and supplements may not act like the prescription medicine containing yohimbine. [2] | Insufficient evidence | Supplement bark products |
Weight-loss claims checked
Bitter orange products became popular after ephedra left the US market and have been promoted as ephedra alternatives. [1] A 2005 systematic review of herbal weight-loss supplements, which included yohimbe, found reports of harms including liver injury and death for some products. [6] The authors said the data did not prove cause in most cases, but that the reported risks shifted the balance against most of the products reviewed. [6] Read the ephedra page for the original case, and weight-loss supplements for goal-level advice. FDA's 2004 rule notes that some other plants, such as Sida cordifolia, also contain ephedrine alkaloids. [7]What is in the bottle
FDA researchers analyzed 59 bitter orange supplements. Of 23 labels that stated the synephrine amount, only 5 were close to it, and six products contained synthetic amines that are not legal dietary ingredients in the US. [1] A 2016 analysis of 49 yohimbe or yohimbine products found yohimbine per serving ranged from none detected to 12.1 mg, only 11 listed an amount, and most of those were inaccurate. [8] NCCIH adds that it is illegal in the US to market an over-the-counter yohimbine product for erectile dysfunction without FDA approval. [2] See quality testing and certifications.Medicines, pregnancy and other cautions
- Antidepressants: NCCIH says not to use yohimbe with monoamine oxidase inhibitors or tricyclic antidepressants. [2] A 2022 emergency report described a brain bleed after yohimbine in a woman taking clonidine, bupropion and desvenlafaxine; the authors said a definitive link could not be proven. [9]
- Caffeine and other stimulants: LactMed says bitter orange is often combined with caffeine and other stimulants in weight-loss products, and the combinations may cause cardiac stimulation. [10]
- Pregnancy and breastfeeding: NCCIH says oral yohimbe might be unsafe. [2] LactMed has no data on bitter orange in breast milk and says nursing mothers should probably avoid it. [10]
- Sport: NCCIH notes the NCAA lists synephrine (bitter orange) as a banned stimulant. [1] See sport certification.
- Children: Proper evidence not found in the sources we read.
- Surgery: Tell the surgical team about every supplement. [11]
Ask a pharmacist or clinician, and see how herbs and medicines interact and blood pressure and heart medicines. Poison-control data: callers about yohimbe were more likely than other callers to need medical care. [2]
Frequently asked questions
Is bitter orange safe?
Food amounts are likely safe, says NCCIH. Supplements raise serious concerns, but it is unclear whether bitter orange itself caused reported heart events. [1]
Does synephrine help with weight loss?
A 2022 meta-analysis found no evidence that it does, and it tended to raise blood pressure and heart rate. [5]
Does yohimbe work for erectile dysfunction or sport?
Not shown. NCCIH says there is not enough research for any condition. [2]
What are warning signs to act on?
Chest pain, fainting, stroke signs or a seizure need 911. Racing heartbeat or high blood pressure after a product should be reported to a clinician. [2][1] Report reactions through side effects and reporting.
Can I use these with antidepressants?
Do not use yohimbe with MAOIs or tricyclic antidepressants. [2] Ask the prescriber or pharmacist before combining any stimulant herb with a medicine.
References
- NCCIH, Bitter Orange (US NIH). Read 2026-10-23.
- NCCIH, Yohimbe (US NIH). Read 2026-10-23.
- GBIF Backbone Taxonomy, Citrus aurantium match record. Read 2026-10-23.
- GBIF Backbone Taxonomy, Pausinystalia johimbe match record. Read 2026-10-23.
- Systematic review and meta-analysis of Citrus aurantium (bitter orange) extracts and p-synephrine, safety and efficacy. Nutrients 2022. Read 2026-10-23.
- Pittler MH et al., Adverse events of herbal food supplements for body weight reduction: systematic review. Obesity Reviews 2005. Read 2026-10-23.
- FDA, Final Rule Declaring Dietary Supplements Containing Ephedrine Alkaloids Adulterated, Federal Register, 11 Feb 2004 (69 FR 6788). Read 2026-10-23.
- Pharmaceutical quantities of yohimbine found in dietary supplements in the USA. Drug Testing and Analysis 2016. Read 2026-10-23.
- Case report, intracranial hemorrhage after a single dose of yohimbine in a chronic user of clonidine. American Journal of Emergency Medicine 2022. Read 2026-10-23.
- LactMed (US NLM), Bitter Orange. Read 2026-10-23.
- NCCIH, Using Dietary Supplements Wisely (US NIH). Read 2026-10-23.