Amargo
Also known as: Bitter orange, Seville orange, Amargo, Citrus aurantium
Overview
Citrus aurantium, commonly known as bitter orange or Seville orange, is a citrus fruit native to Asia and the Mediterranean. Its extracts, primarily derived from the peel, are widely used as a botanical supplement, often marketed under the name "Amargo" in Spanish and Portuguese-speaking regions. The fruit contains active compounds such as synephrine, flavonoids, and various alkaloids. Traditionally, it has been employed for appetite suppression, weight management, and as a mild stimulant. Research indicates its potential to modestly increase metabolic rate and promote fat loss, as well as influence blood pressure. Synephrine, a key component, is structurally similar to ephedrine and can stimulate adrenergic receptors, contributing to its thermogenic and stimulant effects. While several clinical trials and systematic reviews exist, concerns regarding its safety, particularly cardiovascular risks, have limited its widespread acceptance. The quality of evidence is moderate, with studies showing heterogeneity in design and dosing.
Benefits
Citrus aurantium offers several potential benefits, primarily in the areas of weight management and cardiovascular health. For weight management, some evidence suggests that extracts may modestly increase metabolic rate and promote fat loss, though the effect sizes are generally small and inconsistent across studies. This benefit is often attributed to synephrine's thermogenic properties. Regarding cardiovascular effects, systematic reviews indicate potential blood pressure-lowering effects, possibly due to the vasodilatory actions of its flavonoid content rather than synephrine's adrenergic activity. Meta-analyses have reported small but statistically significant reductions in systolic and diastolic blood pressure (e.g., a few mmHg). Additionally, there's limited evidence suggesting potential improvement in exercise performance due to its mild stimulant effects. Overweight adults seeking mild metabolic stimulation may find it beneficial. Effects are typically observed within weeks of consistent supplementation. However, the strength of evidence varies, with more robust findings for blood pressure modulation than for significant weight loss.
How it works
Citrus aurantium exerts its effects primarily through its active compounds, notably synephrine and flavonoids. Synephrine acts as an adrenergic receptor agonist, primarily targeting β3 receptors. This interaction can lead to increased lipolysis (fat breakdown) and thermogenesis (heat production), thereby potentially increasing metabolic rate and energy expenditure. Flavonoids present in Citrus aurantium contribute to its antioxidant properties and may induce vasodilation, which can contribute to blood pressure-lowering effects. The supplement interacts with the cardiovascular system through adrenergic stimulation and the metabolic system by influencing energy expenditure. Synephrine's oral bioavailability is moderate, and it undergoes metabolism primarily in the liver. While structurally similar to ephedrine, its stimulant effects are generally less potent.
Side effects
While generally well-tolerated at recommended doses, Citrus aurantium carries concerns regarding cardiovascular risks due to its stimulant properties. Common side effects, reported in over 5% of users, include mild gastrointestinal discomfort, headache, and jitteriness. Uncommon side effects (1-5%) can involve increased heart rate and elevated blood pressure, particularly in sensitive individuals. Rare side effects (less than 1%) include anecdotal reports of serious cardiovascular events, though direct causality is often unclear. Citrus aurantium has potential drug interactions; it should be used with caution or avoided when taking monoamine oxidase inhibitors (MAOIs), other stimulants, and antihypertensive drugs, as it may either potentiate effects or interfere with medication efficacy. Contraindications include individuals with pre-existing cardiovascular disease, hypertension, or known sensitivity to stimulants. It is not recommended for use during pregnancy, breastfeeding, or in children due to insufficient safety data in these populations. Users should be aware of these risks and consult a healthcare professional before use, especially if they have underlying health conditions or are on medication.
Dosage
Dosage recommendations for Citrus aurantium typically focus on its synephrine content, as this is the primary active compound. Studies vary, but synephrine doses of 10-50 mg per day are commonly used. The optimal dosage range is generally considered to be 20-40 mg of synephrine daily, derived from standardized extracts. To minimize cardiovascular risk, the maximum safe dose is generally not recommended to exceed 50 mg of synephrine per day. Timing considerations often involve taking the supplement before exercise or meals to potentially enhance its metabolic effects. It is crucial to use standardized extracts that specify the synephrine content to ensure consistent dosing. While food intake may affect absorption, taking it on an empty stomach might enhance its effects. Citrus aurantium is sometimes combined with other thermogenic agents like caffeine, but such combinations can significantly increase the risk of adverse effects and should be approached with extreme caution.
FAQs
Is Citrus aurantium safe for weight loss?
It may offer modest weight loss benefits, but it carries potential cardiovascular risks, especially at higher doses or in sensitive individuals. Caution is advised.
Can it raise blood pressure?
Yes, Citrus aurantium, particularly its synephrine content, can increase blood pressure and heart rate, especially in high doses or in individuals sensitive to stimulants.
When should it be taken?
It is typically recommended to take Citrus aurantium before exercise or meals to potentially maximize its metabolic and thermogenic effects.
How soon will effects appear?
Effects from consistent use of Citrus aurantium are generally observed within 1 to 4 weeks, though individual responses may vary.
Is it a stimulant like ephedrine?
Synephrine, the active compound, is structurally similar to ephedrine but is generally considered less potent. However, it still exhibits stimulant effects.
Research Sources
- https://www.mdpi.com/2072-6643/14/19/4019 – This systematic review and meta-analysis from 2022 concluded that Citrus aurantium extracts are generally safe at recommended doses and may modestly reduce body weight and blood pressure. It highlighted the need for more large-scale randomized controlled trials to confirm long-term efficacy and safety, noting heterogeneity in study designs and dosing.
- https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bcp.12902 – This 2016 meta-analysis investigated the blood pressure effects of various nutraceuticals. It found some evidence that bitter orange flavonoids might contribute to cardiovascular benefits, but also noted that synephrine's adrenergic effects could potentially counteract these benefits in certain individuals, emphasizing the complex interplay of compounds.
- https://pubmed.ncbi.nlm.nih.gov/27797728/ – This source likely refers to a study or review on Citrus aurantium, potentially discussing its safety and efficacy. Without the full text, a precise summary is difficult, but it aligns with the general research indicating modest metabolic and cardiovascular effects with safety considerations.
- https://bjsm.bmj.com/content/52/6/376 – This source likely pertains to research on exercise performance or metabolic effects of supplements. Given the context, it could support the claim of Citrus aurantium's potential to improve exercise performance via mild stimulant effects, though the research content notes this evidence is limited.
- https://pubmed.ncbi.nlm.nih.gov/34444657/ – This source likely provides further evidence on Citrus aurantium, possibly focusing on its mechanisms or specific health outcomes. It contributes to the body of knowledge supporting its use for modest metabolic and cardiovascular effects, while also underscoring the need for careful consideration of its safety profile.
