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Methylsynep.

Methylsynephrine

stimulant· Energy
D-Tier · Preliminary6 citations
Found in 3 products
Mechanism of Action +

### Overview of Sympathomimetic Action

Methylsynephrine (oxilofrine) is a synthetic stimulant classified as a sympathomimetic amine. The provided sources do not contain sufficient data to construct a PhD-level biochemical mechanism, including specific enzyme EC numbers, receptor binding affinities, or detailed pharmacokinetic parameters (Tmax, bioavailability, half-life). Its mechanism is inferred from its structural relationship to other phenethylamines like synephrine and ephedrine and its observed physiological effects.

### Adrenergic Receptor Agonism

As a sympathomimetic, methylsynephrine likely functions as an agonist at adrenergic receptors. These G-protein coupled receptors are the primary targets of the catecholamines epinephrine and norepinephrine. The stimulation of these receptors initiates the 'fight-or-flight' response. It is plausible that methylsynephrine interacts with:

* **Beta-Adrenergic Receptors (β1, β2, β3):** Agonism at β1 receptors in the heart would increase heart rate (chronotropy) and contractility (inotropy). Stimulation of β2 receptors could lead to bronchodilation and vasodilation in skeletal muscle. Agonism at β3 receptors, primarily found in adipose tissue, would promote lipolysis and increase metabolic rate, which is the theoretical basis for its inclusion in 'fat-burner' supplements. * **Alpha-Adrenergic Receptors (α1, α2):** Stimulation of α1 receptors would cause vasoconstriction in peripheral blood vessels, contributing to an increase in blood pressure.

### Pharmacokinetics

The provided sources do not contain information on the pharmacokinetics of methylsynephrine, such as its oral bioavailability, time to maximum concentration (Tmax), or elimination half-life. Its legal status as a non-dietary ingredient has limited the amount of publicly available clinical research on these parameters in a supplement context.

Works Best With
Caffeine and other stimulants
Caffeine and other stimulants
Methylsynephrine is often included in complex stimulant blends. Combining multiple stimulants can have an additive or synergistic effect on the cardiovascular system, potentially increasing the risk of adverse events like arrhythmia, heart attack, and stroke. This is a potentially dangerous combination.
Questions About Methylsynephrine
What is Methylsynephrine? +
Methylsynephrine, also known as oxilofrine, is a potent synthetic stimulant. It is structurally similar to ephedrine and synephrine and has been illegally included in some dietary supplements marketed for fat loss and performance enhancement. It is not a legal dietary ingredient in the United States.
Is Methylsynephrine legal? +
No, methylsynephrine is not a legal dietary ingredient. The FDA has determined that it does not meet the definition of a dietary supplement under the 1994 DSHEA Act. The agency has issued warning letters to companies for selling products containing it.
Is Methylsynephrine banned in sports? +
Yes, methylsynephrine is on the World Anti-Doping Agency (WADA) Prohibited List. Athletes who test positive for this substance face sanctions, including suspension from competition. It is considered a performance-enhancing drug.
What are the side effects of Methylsynephrine? +
While clinical data from supplement use is scarce, its stimulant properties suggest potential side effects include increased heart rate, elevated blood pressure, anxiety, jitters, and palpitations. Dr. Pieter Cohen warned that high doses could over-stimulate the heart and lead to serious health problems.
What is the recommended dose of Methylsynephrine? +
There is no recommended or safe dose for methylsynephrine as a dietary supplement. It is an illegal ingredient, and studies have shown that the amount listed on a label is often inaccurate, ranging from zero to dangerously high levels like 75mg per serving.
Why was Methylsynephrine put in supplements? +
It was included in supplements, primarily fat burners and pre-workouts, for its potent stimulant and thermogenic effects. Companies sought to provide users with strong feelings of energy and an increased metabolic rate, similar to what was experienced with now-banned ingredients like ephedrine.
Is Methylsynephrine the same as synephrine from bitter orange? +
No, they are different compounds. Synephrine (specifically p-synephrine) is a naturally occurring alkaloid found in bitter orange extract. Methylsynephrine is a more potent, synthetic stimulant. While related chemically, methylsynephrine has a stronger effect on the cardiovascular system and is not legal for use in supplements.
Can I trust a supplement label that lists Methylsynephrine? +
No. Research by Dr. Pieter Cohen found that supplement labels listing methylsynephrine are highly unreliable. Many products contained none at all, while others contained dangerously high, unlisted amounts. Its very presence on a label indicates an illegal product.
What did the FDA do about Methylsynephrine? +
In 2016, the FDA issued seven warning letters to supplement companies for selling products containing methylsynephrine. The agency declared it an illegal dietary ingredient, making any supplement containing it adulterated and subject to seizure.
Who should not take Methylsynephrine? +
No one should take supplements containing this illegal ingredient. It is especially dangerous for athletes, individuals with any cardiovascular conditions, people sensitive to stimulants, and those taking prescription medications.
Are there natural sources of Methylsynephrine? +
While some manufacturers have claimed it can be found in nature, such as in the plant Acacia rigidula, the FDA's position is that it is a synthetic substance that does not qualify as a dietary ingredient. The dominant view is that it is of synthetic origin in supplements.
Can you stack Methylsynephrine with other supplements? +
Stacking methylsynephrine, especially with other stimulants like caffeine, is extremely risky. Combining stimulants can have an additive effect on the heart and nervous system, significantly increasing the risk of adverse events like heart palpitations, high blood pressure, or worse.
How does Methylsynephrine work? +
It is believed to work as a sympathomimetic agent by stimulating adrenergic receptors, similar to adrenaline. This action increases heart rate, blood pressure, and metabolic rate, which produces its stimulant and thermogenic effects. Detailed clinical research on its precise mechanism in humans is lacking.
What are the aliases for Methylsynephrine? +
Methylsynephrine is also known as Oxilofrine, p-hydroxyephedrine, 4-HMP, and 1-Hydroxypholedrine. If you see any of these names on a supplement label, it refers to the same illegal ingredient.
Do I need to cycle Methylsynephrine? +
You should not take methylsynephrine at all, so cycling is not applicable. Taking a potent, illegal stimulant regularly would pose significant health risks and lead to tolerance, requiring higher doses for the same effect, further increasing danger.
Research Highlights
Cohen, P.A. et al., 2016analytical
An analysis of dietary supplements containing oxilofrine
Of 23 supplements tested, many had no detectable methylsynephrine, while others contained doses ranging up to 75mg per serving. This highlights extreme manufacturing inconsistency and potential danger to consumers.
Deep Content
Everything About Methylsynephrine Article

## The Definitive Guide to Methylsynephrine (Oxilofrine)

Methylsynephrine, also known by its pharmaceutical name oxilofrine or alias 4-HMP, is a potent synthetic stimulant that has appeared in dietary supplements, particularly those marketed for fat loss and athletic performance. However, its presence in supplements is illegal in the United States, and it is a banned substance in competitive sports. This guide will break down what the science and regulatory bodies say about this controversial ingredient.

## What It Is & What It Does

Methylsynephrine is a synthetic drug that is structurally similar to other stimulants like ephedrine and synephrine (found in bitter orange). As a sympathomimetic amine, it stimulates the sympathetic nervous system—the body's 'fight-or-flight' response. This action is believed to be mediated through its interaction with adrenergic receptors, leading to:

* **Increased Heart Rate and Blood Pressure:** By stimulating the heart and constricting blood vessels. * **Increased Metabolic Rate:** It may boost metabolism and thermogenesis (heat production), which is why it's included in 'fat burner' products. * **Enhanced Energy and Alertness:** As a central nervous system stimulant.

Despite these purported effects, it is crucial to understand that methylsynephrine is **not a legal dietary ingredient** according to the FDA.

## The Science: A Story of Adulteration and Risk

The scientific focus on methylsynephrine has not been on its benefits, but on its illicit presence in supplements. A key investigation led by Dr. Pieter Cohen and published in *Drug Testing and Analysis* exposed the dangers of this ingredient in the consumer market.

His team analyzed 23 supplements that listed methylsynephrine on the label and found alarming inconsistencies:

* Many products contained **no detectable amount** of the ingredient, meaning consumers were being misled. * Other products contained pharmacological doses, with one product containing as much as **75mg per serving**.

Dr. Cohen warned, "if supplements contained prescription-doses of oxilofrine, then I would be extremely worried about the health effects. We would worry that high doses of oxilofrine would over-stimulate the heart, increase blood pressure and possibly lead to much more serious health problems."

## Regulatory Status: FDA Warnings and WADA Ban

Following the publication of this research, the FDA took action. In March 2016, the agency issued warning letters to seven companies, stating that methylsynephrine does not meet the definition of a dietary ingredient under the Dietary Supplement Health and Education Act (DSHEA) of 1994. Therefore, any supplement containing it is considered adulterated and illegal.

Furthermore, methylsynephrine is explicitly listed on the World Anti-Doping Agency (WADA) **Prohibited List**. Athletes subject to anti-doping rules will test positive if they consume this substance, leading to sanctions and disqualification.

## Dosing: A Dangerous Guessing Game

There is **no safe or recommended dose** for methylsynephrine in a dietary supplement context. The doses found in illicit products have ranged from zero to 75mg. The fact that you cannot trust the label makes any consumption a significant risk. The presence of this ingredient on a label is a clear sign to avoid the product entirely.

## Who Should NOT Take It

Given its illegal status and potential health risks, **no one should consume supplements containing methylsynephrine**. However, certain populations are at an even greater risk:

* **Athletes:** Face a guaranteed failed drug test. * **Individuals with Heart Conditions:** The cardiovascular strain could be dangerous or even fatal. * **People Sensitive to Stimulants:** Risk of severe anxiety, jitters, and palpitations. * **Anyone Taking Medication:** The risk of drug interactions is unknown but likely significant.

## The Bottom Line

Methylsynephrine (oxilofrine) is a potent, unapproved synthetic drug that has been illegally included in some dietary supplements. Research has shown that products containing it are unreliable and potentially dangerous, with doses varying wildly. It has been subject to FDA warnings and is banned in sports. Consumers should avoid any product that lists methylsynephrine, oxilofrine, or 4-HMP on its label.

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