Get Your Personalized Supplement StackSupplement Stack Quiz

Aurantium

Also known as: Bitter orange, Seville orange, p-Synephrine, Citrus aurantium

Overview

Citrus aurantium, commonly known as bitter orange or Seville orange, is a citrus fruit whose extracts, particularly the primary active alkaloid p-synephrine, are widely used in dietary supplements. These supplements are primarily marketed for weight management and enhancing exercise performance. The fruit's peel is the main source of these extracts. Its purported applications include appetite suppression, thermogenesis (heat production), and enhancement of fat oxidation. While some research suggests potential metabolic effects, the overall evidence for significant weight loss or body composition changes is inconsistent and often lacks strong scientific backing. The research maturity for Citrus aurantium is moderate, with several randomized controlled trials and systematic reviews available, though the quality and consistency of findings vary. Safety concerns, particularly regarding cardiovascular effects, have been noted in some studies.

Benefits

Despite its widespread use in weight management supplements, meta-analyses consistently indicate that *Citrus aurantium* or p-synephrine supplementation does not produce significant weight loss or changes in body composition compared to placebo, even after prolonged use. Therefore, its benefit for weight loss is not supported by high-quality evidence. Some studies suggest that *C. aurantium* intake before submaximal aerobic exercise may be safe in healthy males, showing no significant adverse effects on heart rate or blood pressure recovery post-exercise. However, this does not translate to a performance-enhancing benefit. While some research reports increased energy expenditure and fat oxidation, these findings are inconsistent and often based on heterogeneous data, making it difficult to draw definitive conclusions about metabolic benefits. Robust evidence for specific population benefits is lacking, with most data derived from healthy adults.

How it works

The primary active compound in *Citrus aurantium*, p-synephrine, functions as a sympathomimetic agent. It is structurally similar to ephedrine but is believed to have weaker activity at adrenergic receptors. Its main mechanism involves targeting beta-3 adrenergic receptors, which are thought to promote lipolysis (fat breakdown) and thermogenesis (heat production), potentially increasing energy expenditure. Additionally, p-synephrine can stimulate alpha-1 and beta-1 adrenergic receptors, leading to mild increases in heart rate and blood pressure. While the exact oral bioavailability and pharmacokinetics are not fully understood, they appear sufficient to elicit mild stimulant effects within the body.

Side effects

While *Citrus aurantium* extracts are generally considered safe for healthy adults at typical supplement doses, several cardiovascular effects have been noted. Common side effects, occurring in over 5% of users, include mild but statistically significant increases in systolic and diastolic blood pressure and heart rate, especially with prolonged use. Less common side effects (1-5%) reported in some studies include headaches, dizziness, nervousness, irritability, and palpitations. Rare side effects (less than 1%) may include blurred vision, shortness of breath, and musculoskeletal complaints. There is a potential for additive cardiovascular effects when *Citrus aurantium* is combined with other stimulants or sympathomimetic drugs, and caution is strongly advised in such cases. Individuals with pre-existing conditions such as hypertension, cardiovascular disease, or known sensitivity to stimulants should avoid its use. Safety data for special populations, including pregnant or breastfeeding women, are limited, and its use is not established in these groups.

Dosage

The minimum effective dose of *Citrus aurantium* for any purported effect remains unclear due to inconsistent efficacy data. Typical supplement doses range from 10 to 50 mg of p-synephrine per day. The maximum safe dose has not been firmly established, but prolonged use has been associated with significant increases in blood pressure, potentially up to approximately 6 mmHg systolic. It is often taken pre-exercise or before meals in weight loss protocols, though its efficacy for weight loss is not supported by current evidence. For consistency, standardized extracts with quantified p-synephrine content are preferred. Absorption may be enhanced when taken with food. Co-administration with caffeine can potentiate its stimulant effects, but this also significantly increases the risk of adverse events and is generally not recommended without medical supervision.

FAQs

Does *C. aurantium* cause weight loss?

Current high-quality evidence from meta-analyses indicates that *Citrus aurantium* does not lead to significant weight loss or changes in body composition compared to placebo.

Is it safe for heart health?

It can cause mild increases in blood pressure and heart rate. Caution is warranted, especially for individuals with pre-existing cardiovascular conditions or sensitivity to stimulants.

Can it be combined with caffeine?

Combining *Citrus aurantium* with caffeine may increase both stimulant effects and the risk of side effects. This combination is generally not recommended without medical supervision.

How soon do effects appear?

Cardiovascular effects, such as mild increases in heart rate and blood pressure, can be acute. Any purported weight loss effects, if they existed, would require prolonged use, but current evidence does not support this.

Research Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC9572433/ – This systematic review and meta-analysis, Koncz et al. (2022), analyzed 18 RCTs and found that p-synephrine significantly increased systolic and diastolic blood pressure but showed no significant effect on weight loss or body composition. The study highlighted heterogeneity in caffeine use and dosing among included studies.
https://pubmed.ncbi.nlm.nih.gov/36235672/ – Bahar et al. (2023) conducted a PRISMA-compliant systematic review and meta-analysis of 18 placebo-controlled RCTs. They concluded that *Citrus aurantium* significantly increased blood pressure but did not lead to significant weight loss, raising safety concerns due to limited long-term data and variability in study design.
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2042-7166.2011.01115.x – Stohs et al. (2011) performed a systematic review of multiple RCTs on *Citrus aurantium*. They found contradictory evidence regarding weight loss and reported various adverse events. The review noted significant methodological flaws and small sample sizes in many of the included RCTs, calling for more rigorous research.
https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.890388/full – This source, also Koncz et al. (2022), provides the full text of the systematic review and meta-analysis. It details the methodology and findings regarding the effects of p-synephrine on blood pressure and lack of significant weight loss, emphasizing the need for more controlled studies.