Methyl Synephrine Hcl
Also known as: Methylsynephrine, p-hydroxyephedrine, Oxilofrine
Overview
Oxilofrine, also known as methylsynephrine or p-hydroxyephedrine, is a synthetic stimulant structurally related to synephrine and ephedrine. Unlike naturally occurring p-synephrine found in Citrus aurantium, oxilofrine is not naturally derived. It is primarily used as a stimulant to increase energy, enhance athletic performance, and promote weight loss, often found in dietary supplements. However, it is not approved as a dietary supplement ingredient by the FDA in the US and is banned in sports due to its potent sympathomimetic effects, which include increasing heart rate and blood pressure. Research on oxilofrine is limited to safety concerns and regulatory assessments, with no high-quality human clinical trials or meta-analyses supporting its efficacy or safety as a supplement ingredient.
Benefits
Despite claims of increasing energy, enhancing athletic performance, and promoting weight loss by stimulating adrenergic receptors, there is no high-quality clinical evidence to support significant benefits in humans. Any purported benefits are largely extrapolated from the mechanisms of related compounds like p-synephrine, which itself has limited evidence for weight loss and known cardiovascular risks. No specific population-specific benefits have been established due to the lack of clinical trials. The quality of available evidence is primarily regulatory reports, case studies, and reviews focusing on safety concerns, rather than robust efficacy data from independent clinical trials. Therefore, no evidence-based benefits can be confidently stated for oxilofrine.
How it works
Oxilofrine functions as a sympathomimetic amine, primarily by stimulating adrenergic receptors, specifically alpha-1, beta-1, and beta-2 receptors. This interaction leads to a cascade of physiological responses characteristic of the 'fight or flight' response. Its primary action involves stimulating the cardiovascular system, resulting in increased heart rate and elevated blood pressure. Additionally, it exerts central nervous system stimulant effects. While its exact absorption and bioavailability in humans are not well characterized, it is presumed to have oral bioavailability similar to other related phenethylamines.
Side effects
Oxilofrine is considered unsafe as a dietary supplement ingredient by the FDA and is prohibited in sports due to its significant stimulant effects and potential cardiovascular risks. Common side effects include increased heart rate, elevated blood pressure, agitation, nausea, and vomiting. Less common but serious side effects can include chest pain and palpitations. Rare but severe adverse events, such as cardiac arrest, have been reported in case studies involving supplements containing oxilofrine, especially when combined with other stimulants. It carries potentially dangerous interactions with other stimulants, monoamine oxidase inhibitors (MAOIs), and cardiovascular drugs. Contraindications include cardiovascular disease, hypertension, arrhythmias, pregnancy, and lactation. It is not recommended for athletes, pregnant women, or individuals with pre-existing cardiovascular risk factors.
Dosage
The minimum effective dose and optimal dosage ranges for oxilofrine are not established due to a complete lack of clinical trials. Some supplements have been found to contain doses comparable to pharmaceutical levels, raising significant safety concerns. A maximum safe dose has not been determined, and high doses are explicitly linked to adverse cardiovascular events. There are no defined timing considerations or form-specific recommendations, as oxilofrine is not approved as a dietary supplement ingredient. Its absorption factors are also unknown. No specific cofactors are known to be required for its action.
FAQs
Does methylsynephrine help with weight loss?
There is no high-quality scientific evidence to support claims that methylsynephrine effectively aids in weight loss. Its use for this purpose is not recommended.
Can methylsynephrine cause heart problems?
Yes, methylsynephrine can significantly increase heart rate and blood pressure, and its use has been linked to serious cardiovascular events, including cardiac arrest in some cases.
Is methylsynephrine the same as p-synephrine?
No, they are different. Methylsynephrine is a synthetic stimulant with stronger cardiovascular effects and is regulated differently than p-synephrine, which is naturally occurring.
Can athletes use methylsynephrine?
No, methylsynephrine is a prohibited substance in sports due to its stimulant properties and potential performance-enhancing effects, making its use by athletes illegal.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9572433/ – This systematic review and meta-analysis focused on p-synephrine, not methylsynephrine. It found that p-synephrine increases blood pressure and heart rate but showed no significant weight loss effect. While not directly on methylsynephrine, it highlights cardiovascular concerns with related compounds.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7830131/ – This narrative review primarily discussed p-synephrine, suggesting it is safe at typical doses and does not cause adverse cardiovascular effects in controlled studies. However, it explicitly did not include methylsynephrine, underscoring the distinction between the two compounds.
- https://www.opss.org/article/methylsynephrine-illegal-ingredient – This source, likely from a regulatory or safety organization, indicates that methylsynephrine is an illegal ingredient in dietary supplements. It links the compound to adverse cardiovascular events, reinforcing the safety concerns from a regulatory perspective.
- https://onlinelibrary.wiley.com/doi/full/10.1002/ptr.5879 – This review article by Stohs discusses the safety of p-synephrine, concluding it is generally safe. However, it explicitly states that methylsynephrine and other synthetic analogs are prohibited due to significant safety concerns, differentiating it from p-synephrine.
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