What is hordenine used for?: Examining Its Claims and Evidence

October 7, 2025 •

4 min read

Hordenine, a naturally occurring alkaloid found in barley and other plants, is frequently marketed in dietary supplements for its purported benefits in weight loss and athletic performance. However, sources like WebMD and RxList warn that it is "possibly unsafe" and lacks sufficient scientific evidence to support these common uses.

Quick Summary

An examination of hordenine's purported applications, its underlying pharmacological mechanisms, and the crucial distinction between anecdotal claims and scientific evidence, including safety warnings and regulatory status.

Key Points

Limited Human Evidence: The purported uses of hordenine for weight loss, athletic performance, and cognitive function are not well-supported by human clinical studies.
Possible Stimulant Effects: Hordenine has stimulant-like properties and may influence norepinephrine levels, which can lead to increased heart rate and blood pressure.
Not FDA Approved as Dietary Ingredient: The FDA has determined that hordenine requires a New Dietary Ingredient notification, which has not been submitted, making products containing it adulterated for sale in the US.
Prohibited by Major Organizations: Hordenine is on the banned substance lists for the U.S. Department of Defense and the NCAA.
Potential for Side Effects: Reported side effects include increased heart rate, high blood pressure, anxiety, and dizziness, especially when combined with other stimulants or at high doses.
Drug Interaction Risks: Hordenine can interact with medications like MAOIs, potentially causing serious adverse effects.
Found in Natural Sources: It is naturally found in plants like barley and bitter orange but is most commonly encountered in synthesized form in dietary supplements.

Origins and Proposed Uses of Hordenine

Hordenine is a phenethylamine alkaloid found in plants such as barley (where it gets its name), bitter orange, and certain cacti. It is often synthesized and included in dietary supplements, particularly those marketed for sports nutrition, weight management, and cognitive enhancement. In the supplement industry, it has gained traction as a stimulant alternative, especially after regulations limited the use of substances like ephedra. Proponents claim a variety of benefits, based largely on its perceived pharmacological effects.

Proposed Benefits in Dietary Supplements

Manufacturers and proponents of hordenine-containing supplements claim it can offer several advantages, though the scientific backing for these is often limited or inconclusive. Some of the most frequently mentioned uses include:

Athletic performance enhancement: Marketed to improve endurance, boost energy levels, and reduce fatigue, often as an ingredient in pre-workout formulas.
Weight loss support: Advertised to increase metabolism and suppress appetite, with the potential to promote lipolysis (the breakdown of fat).
Cognitive enhancement: Included in nootropic supplements to enhance focus, mental clarity, and overall cognitive function.
Mood enhancement: Some speculate it may boost mood by influencing dopamine and norepinephrine levels.

Scientific Evidence and Mechanisms of Action

While marketing claims are prevalent, robust scientific evidence from large-scale human clinical trials supporting hordenine's efficacy for these uses is lacking. Much of the research has been conducted in animal models or is preliminary in nature. The proposed mechanisms of action center on its stimulant-like effects and modulation of certain neurotransmitters.

Pharmacological Properties

Norepinephrine release: Hordenine is thought to act as an adrenergic drug by stimulating the release of norepinephrine, a neurotransmitter that increases heart rate, blood pressure, and energy levels.
Monoamine Oxidase B (MAO-B) inhibition: Some research suggests hordenine may act as a mild MAO-B inhibitor, which can prolong the effects of monoamine neurotransmitters like dopamine and norepinephrine. This effect is often cited to support its potential for mood enhancement.
Neuroprotective and Anti-inflammatory effects: Animal studies have explored potential therapeutic applications. One study in a rat model of Parkinson's disease found hordenine exhibited neuroprotective effects by inhibiting inflammatory responses. Another animal study showed a protective effect against immune liver injury. A study on ulcerative colitis in mice also indicated anti-inflammatory and mucosal healing properties.
Effect on Alcohol Use: Research in mice found that hordenine acted as an inhibitory factor for alcohol consumption and diminished relapse drinking.

Safety Concerns and Regulatory Status

Despite its inclusion in many supplements, the safety profile of hordenine is not well-established, and significant concerns have been raised by regulatory bodies. The lack of standardized dosages and robust clinical data makes its use potentially risky.

Official Warnings and Bans

FDA Status: The U.S. Food and Drug Administration (FDA) has classified hordenine as a “new dietary ingredient” (NDI) for which the required safety notification has not been submitted. Consequently, any dietary supplement containing it is considered "adulterated" and should not be sold legally in the US. The FDA has issued warning letters to companies for selling products containing hordenine.
Banned by Sports Organizations: Hordenine is on the Prohibited Dietary Supplement Ingredients list for the U.S. Department of Defense (DoD) and the list of banned substances by the National Collegiate Athletic Association (NCAA).

Potential Side Effects

Cardiovascular: Increased heart rate and blood pressure are commonly reported side effects due to its stimulant properties, posing a risk for individuals with hypertension or other cardiovascular conditions.
Neurological: Other possible side effects include dizziness, anxiety, nervousness, restlessness, and insomnia.
Drug Interactions: Due to its potential MAO-B inhibition, hordenine can interact with certain medications, such as MAOIs used for depression and other stimulant drugs.

Comparison: Marketing Claims vs. Scientific Evidence


Feature	Common Marketing Claim	Scientific Evidence/Regulatory Stance
Weight Loss	Boosts metabolism and suppresses appetite, promoting fat loss.	Insufficient, inconclusive evidence in humans. Mostly based on theoretical stimulant effects observed in animals.
Athletic Performance	Improves energy, endurance, and reduces fatigue.	Inconclusive for humans. Animal studies showed short-lived stimulant effects, but significant performance enhancement was not observed.
Cognitive Function	Enhances focus, alertness, and mental clarity.	Primarily based on proposed neurotransmitter modulation. Limited human evidence. Research suggests potential neuroprotective effects, but clinical application is unproven.
Safety	Generally safe when taken responsibly.	Considered "possibly unsafe" by WebMD and RxList. Associated with side effects like increased heart rate and blood pressure. Banned by several organizations and unauthorized for sale as a dietary ingredient by the FDA.

Conclusion

Hordenine is a plant-derived alkaloid that has gained popularity as an ingredient in dietary supplements for purported use in athletic performance, weight loss, and cognitive enhancement. Its pharmacological properties involve mild stimulant effects and interaction with monoamine neurotransmitters. However, there is a significant discrepancy between these marketing claims and the current scientific evidence in humans, which is largely lacking. Concerns surrounding its safety are notable, with potential side effects including cardiovascular issues and drug interactions. Regulatory bodies like the FDA and organizations like the DoD have raised flags, leading to hordenine's classification as an adulterated and prohibited substance in certain contexts. Therefore, while preliminary animal research suggests intriguing potential in areas like neuroprotection, the use of hordenine in supplements for its claimed benefits is not supported by sufficient clinical evidence and carries known health risks that should be carefully considered.

Visit the FDA website for the latest information on dietary supplements and new dietary ingredient rules.

Frequently Asked Questions

Hordenine is commonly marketed in dietary supplements for uses such as weight loss, enhancing athletic performance, and boosting energy and focus.

Yes, hordenine is structurally similar to other natural stimulants and is believed to have stimulant effects, particularly by promoting the release of norepinephrine.

Due to insufficient scientific evidence regarding its safety and efficacy, reputable sources like WebMD consider hordenine "possibly unsafe". Potential side effects include rapid heart rate and high blood pressure.

While marketed for weight loss and increased metabolism, there is insufficient scientific evidence in humans to support these claims. It should not be considered a standalone weight loss solution.

Yes, hordenine can interact with certain medications, including MAOIs used for depression and other stimulants, which could cause serious health issues.

Yes, hordenine is included on the prohibited dietary supplement ingredients lists of organizations such as the U.S. Department of Defense and the NCAA.

The FDA considers hordenine an adulterated dietary ingredient because the required New Dietary Ingredient (NDI) notification to establish its safety has not been submitted or accepted.

Hordenine is a naturally occurring alkaloid found in plants, most notably germinated barley, as well as bitter orange, certain grasses, and cacti.