Get Your Personalized Supplement StackSupplement Stack Quiz

Proprietary Orange Essence

Also known as: Citrus aurantium L., C. sinensis var. amara, Bitter orange, p-Synephrine, 4-[1-hydroxy-2-(methylamino)ethyl]phenol, Citrus aurantium

Overview

Citrus aurantium, commonly known as bitter orange, is a citrus tree whose fruit and peel are used in dietary supplements, often marketed as "Proprietary Orange Essence." The key active compound is p-synephrine, a stimulant with thermogenic properties. Other compounds include octopamine and tyramine. It's primarily used for weight management, athletic performance enhancement, and appetite suppression. Research on Citrus aurantium is moderately mature, with several randomized controlled trials and systematic reviews. Evidence suggests a modest effect on weight loss, but results are dose-dependent and can vary based on formulation and combination with other ingredients like caffeine. The quality of evidence is considered Grade B, indicating mixed outcomes.

Benefits

Citrus aurantium, primarily through its p-synephrine content, has shown some benefits in weight management. Meta-analysis findings indicate a modest weight reduction compared to placebo (WMD: -2.43kg, 95% CI: -3.72 to -1.14) in trials lasting 6-12 weeks. However, effects on body fat reduction are generally non-significant in most studies. While anecdotal evidence suggests appetite suppression, this benefit lacks confirmation from randomized controlled trials. The synergistic effect with caffeine has been noted, potentially enhancing the overall impact on weight loss. The evidence suggests that the benefits are modest and may be more pronounced when combined with other compounds like caffeine.

How it works

Citrus aurantium's primary mechanism of action involves adrenergic activity, specifically through β3-receptor agonism, which stimulates thermogenesis. This process increases cAMP levels via adenylate cyclase activation, leading to lipolysis (the breakdown of fats). p-Synephrine is rapidly absorbed, reaching peak concentration (Tmax) in 1-2 hours, with a half-life of 2-3 hours. Its effects are enhanced when combined with caffeine, potentially increasing the effect size by 1.5-3 times. The interaction with adrenergic receptors impacts metabolic rate and energy expenditure, contributing to its potential weight management effects.

Side effects

Citrus aurantium and its primary active compound, p-synephrine, can cause several side effects. While acute studies show no significant change in blood pressure, chronic use (8+ weeks) may lead to an increase in diastolic blood pressure (ΔDBP +6.37mmHg). Cardiac risk, specifically QT prolongation, has not been observed in RCTs. However, Citrus aurantium is contraindicated for individuals using MAOIs, those with pheochromocytoma, and those with hypertension. Due to insufficient data, it is classified as Pregnancy Category C. Common side effects may include increased heart rate, anxiety, and insomnia. It's crucial to monitor blood pressure and heart rate when using Citrus aurantium supplements. Individuals with pre-existing cardiovascular conditions should avoid its use.

Dosage

The effective dosage range for p-synephrine, the active compound in Citrus aurantium, is typically 10-50mg per day. The maximum safe dosage is considered to be 100mg per day, based on animal studies. It is often recommended to take Citrus aurantium supplements 30-60 minutes before a meal or exercise. Standardized extracts usually contain 6-8% p-synephrine. Dosage should be adjusted based on individual tolerance and the specific product formulation. Due to potential cardiovascular effects, it is advisable to start with a lower dose and gradually increase as tolerated. Individuals should not exceed the recommended upper limit without consulting a healthcare professional.

FAQs

Does it cause jitters like ephedrine?

Citrus aurantium has lower β2 activity compared to ephedrine, which reduces the likelihood of central nervous system stimulation and associated jitters. However, some individuals may still experience mild stimulation.

How long until results appear?

Noticeable weight effects typically manifest after 6 or more weeks of consistent use, with studies showing an average weight loss of 2.5-3kg compared to placebo over this period. Individual results may vary.

Safe with SSRIs?

There is a theoretical risk of serotonin syndrome when combining Citrus aurantium with SSRIs, although case reports are lacking. Caution is advised, and consultation with a healthcare provider is recommended before combining these substances.

What is the best time of day to take it?

It is generally recommended to take Citrus aurantium 30-60 minutes before a meal or workout. This timing allows the active compounds to be absorbed and exert their effects during periods of increased metabolic activity.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/33976376/ – Bui et al.'s meta-analysis of 14 supplement studies (n=488) confirmed the synergistic effects of Citrus aurantium with caffeine. However, the study found inconclusive evidence for the standalone efficacy of Citrus aurantium. The variable quality of the included studies (Jadad scores 3-5/5) was noted as a limitation.
https://www.mdpi.com/2072-6643/14/19/4019 – Koncz et al.'s (2022) systematic review and meta-analysis of 18 RCTs (n=641) found a weight reduction of -2.43kg (95% CI: -3.72, -1.14) associated with Citrus aurantium use. The review also noted a potential increase in diastolic blood pressure (+6.37mmHg) with long-term use. The heterogeneity of formulations (p-synephrine 2-30mg/dose) was identified as a limitation.
https://pubmed.ncbi.nlm.nih.gov/36235672/ – This citation is linked to the Koncz et al. (2022) systematic review and meta-analysis of 18 RCTs (n=641) which found a weight reduction of -2.43kg (95% CI: -3.72, -1.14) associated with Citrus aurantium use. The review also noted a potential increase in diastolic blood pressure (+6.37mmHg) with long-term use.
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2042-7166.2011.01115.x – Stohs et al.'s (2011) systematic review of 8 RCTs reported 2-4kg greater weight loss with Citrus aurantium compared to placebo. The review also indicated no serious adverse events at dosages less than 100mg/day. A limitation of the review was the inclusion of industry-funded studies.
https://ouci.dntb.gov.ua/en/works/4knE6J67/ – This source was not directly used as it was not in English and could not be reliably summarized. Further analysis would be needed to determine its relevance.