Benefits
Energy and fat-burning claims compared with the human research
Halostachine is marketed as a fat burner and for endurance and recovery, but no human trial of oral halostachine has been published. Australia's national anti-doping agency states that clinical data on its efficacy and safety in humans do not exist. Any effect people notice cannot be separated from the caffeine and other stimulants these products usually contain.
What laboratory testing found inside halostachine products
Product analysis only. Of seven supplements bought online that listed halostachine, three held no detectable amount and four held 0.5 to 3.0 mg per serving, 1.3% to 3.0% of the label amount where one was given (40 or 100 mg). Three of the seven also contained the stimulant deterenol, and one also held undeclared 1,4-DMAA and octodrine.
Detection in supplements sold in Australia and near US military bases
Product surveys only. Among 200 sports supplements bought online in Australia, halostachine was detected in 10 (7 fat burners and 3 pre-workouts) and classed with the in-competition stimulants. In 44 weight-loss supplements bought on or near US military bases, it was listed and detected in two products; amounts were not measured.
Adrenergic and trace amine receptor activity in cell assays
Laboratory work only. In cells carrying human receptors, halostachine partly activated the three alpha-1 adrenergic receptor subtypes (59% to 82% of the adrenaline maximum) at low micromolar concentrations and weakly activated TAAR1, but it did not activate beta-1, beta-2 or alpha-2 receptors at concentrations up to 300 micromolar.
Blood vessel contraction in isolated rat arteries
Animal tissue only. Halostachine contracted rat aorta segments (EC50 1.29 micromolar; nearly 100% of the phenylephrine maximum) and renal arteries (EC50 1.37 micromolar), with a potency close to synephrine, but did not contract mesenteric arteries. The alpha-1 blocker prazosin abolished the aorta response. The authors warned of possible blood pressure effects in people.
Blood pressure and body temperature in rats given injections
Animal research only. In conscious rats monitored by telemetry, intravenous halostachine was among the phenethylamines that significantly changed arterial pressure (peak increases of 65 to 103 mmHg across those compounds) and among four that quickly lowered body temperature. Injected doses in rats do not show what an oral supplement does in people.
Mechanism of action
Partial agonist at alpha-1 adrenergic receptors, not beta receptors
In human receptor cell assays, halostachine activated alpha-1A, alpha-1B and alpha-1D receptors (EC50 8.7, 1.1 and 2.1 micromolar) as a partial agonist and did not activate beta-1, beta-2, alpha-2A or alpha-2B receptors up to 300 micromolar, although it is often described as a beta-2 agonist. In rat arteries its contraction was blocked by prazosin, an alpha-1 blocker.
Weak activity at the trace amine receptor TAAR1
Halostachine activated human TAAR1 in a cell assay only at higher concentrations (EC50 74 micromolar; 104% of the phenethylamine maximum). In rat aorta and renal artery segments, the TAAR1 blocker EPPTB shifted its contraction curves toward higher concentrations, suggesting a minor TAAR1 role. All of this is laboratory and animal tissue work.
Absorption and dose predictions from computer modeling
In gut cell (Caco-2) tests halostachine crossed readily, with a predicted fraction absorbed of 1.00, and human liver fractions broke it down. A model predicted oral doses for half-maximal receptor activation of about 1.3 mg/kg (alpha-1B), 2.5 mg/kg (alpha-1D), 10.5 mg/kg (alpha-1A) and 89 mg/kg (TAAR1). These are predictions, not measurements in people.
Breakdown by monoamine oxidase and clearance in dogs
A 1980 enzyme study characterized N-methylphenylethanolamine as a substrate for both type A and type B monoamine oxidase (MAO). In dogs given single intravenous doses, its plasma elimination half-life was about 30 to 60 minutes. How quickly people clear oral halostachine has not been measured.
Clinical trials
Laboratory analysis by liquid chromatography with quadrupole time-of-flight mass spectrometry of 57 sports supplements bought online and labeled with one of five botanical ingredients, seven of them listing halostachine. (Cohen et al. 2023, JAMA Netw Open)
7 supplements bought online and labeled with halostachine or Halostachys extract, within a set of 57 products; no human participants.
Three of the seven halostachine products held no detectable halostachine (limit of detection 50 ng/mL). The other four held 0.5, 1.0, 2.0 and 3.0 mg per serving; where labels gave an amount (40 or 100 mg), measured amounts were 1.3% to 3.0% of it. Three products contained deterenol, and one also contained oxilofrine, 1,4-DMAA and octodrine, the last two not on its label. Across all 57 products, only 11% were within 10% of the labeled quantity.
Survey funded by Sport Integrity Australia: 200 sports supplements bought in the Australian online marketplace in 2022 and analyzed for substances on the World Anti-Doping Agency Prohibited List. (Barker et al. 2025, Drug Test Anal)
200 sports supplement products; no human participants.
35% of products contained a prohibited substance, mostly stimulants, and 57% of those did not list the substance on the label. Halostachine was detected in 10 products (7 fat burners and 3 pre-workouts) and classed with the S6.B specified stimulants. The halostachine results were not broken down by amount or by whether it was declared.
Case series analyzing label accuracy by liquid chromatography with mass spectrometry in weight-loss supplements bought at stores on or near 12 US military installations from March 2023 to January 2024. (Crawford et al. 2024, Nutrients)
44 weight-loss supplement products; no human participants.
36 products (82%) had inaccurate labels and 16 (36%) contained hidden ingredients. Halostachine was listed and detected in one product bought on a base and one bought within a mile of a base; the authors noted it is prohibited in sport by WADA but not on the Defense Department prohibited list. Ingredient amounts were not quantified.
In vitro study of phenethylamine and alkylamine supplement ingredients in cell lines overexpressing human adrenergic receptor subtypes or TAAR1, funded by the Dutch Ministry of Agriculture, Nature and Food Quality. (Pinckaers et al. 2024, Nutrients)
Engineered cell lines carrying human receptors; no human participants.
Halostachine activated alpha-1A (EC50 8.7 micromolar; 59% of the adrenaline maximum), alpha-1B (1.1 micromolar; 77%) and alpha-1D (2.1 micromolar; 82%) receptors and TAAR1 (74 micromolar; 104% of the phenethylamine maximum). It did not activate alpha-2A, alpha-2B, beta-1 or beta-2 receptors up to 300 micromolar. Laboratory findings only.
Physiologically based kinetic modeling with reverse dosimetry, using gut cell permeability, human liver S9 metabolism and the earlier receptor data, for phenethylamine analogues found in pre-workout supplements. (Pinckaers et al. 2025, Arch Toxicol)
Computer model built from cell and liver fraction experiments; no human participants.
Halostachine crossed a Caco-2 gut cell layer readily (predicted fraction absorbed 1.00) and was metabolized by human liver S9. Predicted oral doses for half-maximal activation were 1.32 mg/kg (alpha-1B), 2.52 mg/kg (alpha-1D), 10.5 mg/kg (alpha-1A) and 88.9 mg/kg (TAAR1). No reported intake was available for comparison; the authors ranked higenamine, isopropyloctopamine, BMPEA and synephrine as the highest priorities.
Wire myograph study of isolated mesenteric artery, renal artery and aorta segments from Wistar Kyoto rats, testing phenethylamine and alkylamine supplement ingredients with an alpha-1 blocker or a TAAR1 blocker. (Pinckaers et al. 2026, Cardiovasc Toxicol)
Artery segments from rats; no human participants.
Halostachine contracted aorta segments (EC50 1.29 micromolar; 99.9% of the phenylephrine maximum) and renal arteries (EC50 1.37 micromolar; 61.8%) but not mesenteric arteries. Prazosin completely blocked the aorta response and almost completely blocked the renal response, and the TAAR1 blocker EPPTB shifted the curves to higher concentrations. Its aorta potency was close to that of synephrine (0.906 micromolar).
Pressure telemetry study in conscious Wistar Kyoto rats given cumulative intravenous doses of phenethylamine and seven analogues, including halostachine; one author reported support from the Dutch agriculture ministry. (Pinckaers et al. 2026, Eur J Pharmacol)
Conscious rats (number not given in the abstract); no human participants.
All compounds except phenethylamine and BMPEA, so including halostachine, significantly changed arterial pressure, with maximal increases of 65 to 103 mmHg across those compounds. Halostachine was one of four analogues that immediately lowered body temperature (by 0.5 to 1.5 degrees C across the four). The abstract does not give values for halostachine alone; the full text was not accessed.
Single intravenous doses of phenylethanolamine or its N-methyl homolog (halostachine), with pupil size, heart rate, body temperature and plasma levels measured over time. (Shannon et al. 1981, J Pharmacol Exp Ther)
Dogs, five per compound; no human participants.
Both compounds dilated pupils, lowered heart rate and tended to lower body temperature; the N-methyl form was about 1.25 times as potent at dilating pupils. Elimination half-lives were about 30 to 60 minutes, and only N-methylphenylethanolamine plasma levels correlated with heart rate and temperature changes. Injected doses in dogs; no oral or human data.