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Synephrine Hydrochloride

Also known as: Synephrine, 4-[1-hydroxy-2-(methylamino)ethyl]benzene-1,2-diol, Bitter Orange Extract, Citrus aurantium Extract, Synephrine Hydrochloride

Overview

Synephrine hydrochloride is a salt form of synephrine, a naturally occurring compound primarily found in bitter orange (Citrus aurantium). It is categorized as a dietary supplement used for weight loss and enhancing sports performance. Synephrine acts as a sympathomimetic agent, influencing the cardiovascular system by increasing blood pressure and heart rate. While it's commonly included in dietary supplements, the research regarding its efficacy for weight loss is inconclusive, and concerns regarding its cardiovascular effects persist. The evidence supports an increase in cardiovascular parameters, but its benefits for weight reduction remain unsubstantiated, necessitating further high-quality research to confirm its effects and safety.

Benefits

Research indicates that synephrine may increase blood pressure and heart rate, which can potentially improve physical performance in certain contexts, particularly during exercise. However, definitive evidence supporting its efficacy for weight loss is lacking. Some potential secondary effects include anti-inflammatory properties and modulation of immune response; however, these effects require more comprehensive studies in humans. Populations considering synephrine should be cautious due to cardiovascular risks associated with its use. Effect sizes for cardiovascular effects are significant, yet the clinical significance regarding weight loss is minimal and warrants careful consideration.

How it works

Synephrine primarily acts through adrenergic receptors (α and β adrenergic receptors), leading to an increase in cardiovascular metrics such as heart rate and blood pressure. This action occurs via sympathomimetic mechanisms, stimulating the sympathetic nervous system and influencing energy metabolism. The compound's low oral bioavailability indicates that it undergoes considerable metabolism before achieving systemic effects, impacting its efficacy and duration of action.

Side effects

Common side effects of synephrine include increased heart rate and elevated blood pressure, which can pose risks, especially when taken with caffeine or during physical exertion. Uncommon side effects may include cardiac arrhythmias and other cardiovascular complications. Rare cases of severe cardiovascular events, such as myocardial infarction, have been documented in select individuals. Caution is advised for those on medications that affect cardiovascular parameters or possess pre-existing health conditions related to heart health. Pregnant women, children, and individuals suffering from hypertension or existing heart disease should avoid synephrine due to these potential risks.

Dosage

Recommendations for synephrine dosing vary, as definitive guidelines are not established. Typical doses range from 10 to 50 mg but caution is advised when determining individual needs due to possible cardiovascular risks. There is no clear optimal dosage for weight loss or performance enhancement, and the maximum safe dose is not well-defined. Timing considerations for efficacy are not sufficiently documented; however, individuals should be aware that food intake may influence its absorption. Lastly, it has been noted that no specific cofactors are necessary for effective absorption.

FAQs

Is synephrine safe to use?

Synephrine poses cardiovascular risks, especially when combined with caffeine or during exercise, thus caution is necessary for individuals with heart conditions.

What results can I expect from using synephrine?

Users may experience increased heart rate and blood pressure; however, scientific evidence supporting significant weight loss is lacking.

Can I take synephrine with other supplements?

It is advised to avoid synephrine with other stimulants like caffeine due to compounded cardiovascular risks.

Is there an optimal time to take synephrine?

Specific timing recommendations for synephrine intake are not well established; users should approach its use with caution.

Is it true that synephrine can help with weight loss?

This is a common misconception; evidence does not support synephrine as an effective weight loss aid.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/36235672/ – This meta-analysis reviewed 18 clinical trials and found that while synephrine increases cardiovascular metrics such as blood pressure and heart rate, it does not demonstrate substantial efficacy for weight loss.
https://tnsroindia.org.in/JOURNAL/issue85/ISSUE%2085%20-%20AUG%202024%20-%20FULL%20TEXT%20PART%2003.pdf – This risk assessment compiled data from animal and human studies, identifying significant cardiovascular risks associated with synephrine, especially when paired with caffeine or in physically active individuals.
https://www.rivm.nl/bibliotheek/rapporten/2017-0069.pdf – This pharmacokinetic study found that synephrine has low oral bioavailability and is significantly metabolized in the body, which may impact its therapeutic and safety profiles.
https://pubmed.ncbi.nlm.nih.gov/28058460/ – The provided study examined the pharmacokinetics of synephrine, indicating its low bioavailability and considerable metabolism which limits its efficacy when taken orally.
https://www.mdpi.com/1422-0067/24/24/17537 – This systematic review offers comprehensive insights into synephrine's metabolism and health effects, reaffirming concerns regarding cardiovascular risks and questioning its weight loss effectiveness.