Pharmacological Actions

The dimethylamine alkaloid hordenine is the N,N-dimethylated version of the phenethylamine tyramine. It’s commonly found in herbal supplements where it’s used as an effective MAO-B inhibitor. It's also useful as a norepinephrine (noradrenaline) uptake inhibitor.[1]

Hordenine is a mild short acting CNS stimulant in man that causes a release of norepinephrine. It’s also a highly selective substrate of MAO-B and acts as a temporary reversible MAO-B inhibitor. Because hordenine crosses the blood brain barrier it is able to inhibit MAO-B enzymes in both the body and brain.

Hordenine is also antiasthmatic, antidiarrheal, antifeedant, antispasmodic, bronchorelaxant, cardiotonic, hepatoprotective, sympathicomimetic, and acts as a vasoconstrictor.[2]

Natural Sources

  • Lophophora williamsii (Peyote cactus)[2]
  • Bitter Orange (Citrus Aurantium)
  • Barley seeds and roots

Subjective Effects

The effects of hordenine are similar to other adrenergics (ephedrine, yohimbe, etc.). Compared to ephedrine or yohimbe, it’s often said to be smoother, not jittery or jolting. It can produce mild euphoria. The stimulant effect is very smooth and mild, and can smooth out the rough edges of things like caffeine. It’s a good addition to other stimulants, being somewhat mild on it’s own, but altering the effects of other stimulants often in a very positive way.

50 MG: very mild, slight tingling sensations, very mild stimulation. This is probably the lower dose a person could feel.
100 MG: mild tingling sensations, mild stimulation, very mild euphoria similar to small doses of caffeine.
200 MG: mild tingling sensations, moderate stimulation, mild euphoria similar, general sense of wellbeing. About the potency of 1 cup of coffee.


ONSET: 15-20 minutes
PEAK: 45-60 minutes
DURATION: 2-3 hours roughly, with some mild effects that linger for several hours after.


Adults: 50-400 mg 2-3 times a day.

MAO-B Inhibition

Hordenine’s MAO-B inhibition effects are competitive, rapidly reversible, and very short acting.

Hordenine is a highly selective substrate for MAO-B enzymes.[1] Tests using various MAO inhibitors showed that hordenine is deaminated by MAO-B but not MAO-A.[1].

Hordenine is not a true MAO-B inhibitor. It’s simply a highly selective substrate for MAO-B. In this sense it’s like the MAO-A inhibitor harmaline, meaning it’s only a temporary reversible inhibitor. Hordenine is highly attracted to MAO-B enzymes, but doesn't destroy MAO-B enzymes, instead it temporarily ties them up, allowing other weaker MAO-B substrates to pass through unaffected by MAO-B. In order to reach a good level of inhibition, enough hordenine needs to be taken to tie up a good percentage of MAO-B enzymes. The level needed is reported as 50 mg, however many users report needing 100-200 mg.

As with harmaline, the hordenine dosage needed for good MAO inhibition will vary from person to person. Also as with harmaline, the dose needed for good MAO inhibition will be the dose that is needed to elicit noticeable effects. With hordenine, one should experience norepinephrine style stimulation. At such a dose, MAO inhibition is working. Any dose lower than that means MAO-B enzymes are attacking all the hordenine ingested and so the MAO-B enzymes have not been fully saturated, meaning MAO-B inhibition is incomplete. Once the stimulant effects of hordenine are apparent, MAO-B inhibition should be at a reasonable level. This is usually the dose needed for minimal MAO-B inhibition.

MAO-B Inhibition Dosage

NOTE: Scientific studies are sorely lacking for humans. The following information in this section is based on human bioassays using phenethylamine to determine the effectiveness of the MAO-inhibition at various doses.

The effective MAO-B inhibiting dosage of hordenine is roughly 10 times greater than that of the common MAO-B inhibitor deprenyl (Selegiline).

50 mg: produces mild MAO-B inhibition, and is not enough for some users.
100 mg: produces adequate MAO-B inhibition some users.
200 mg: produces adequate MAO-B inhibition in most users.

Users state that the MAO-B inhibition seems to reach a peak very rapidly after ingestion, and seems to fade away in about 30 minutes or less. When taking hordenine as an MAO-B inhibitor to protect another supplement from MAO-B enzymes, most users get optimal MAO-B inhibition when hordenine is taken with the other supplement. Predosing with hordenine often produces inferior MAO-B inhibition.

Side Effects

Possible side effects include: Nausea, Insomnia, Dizziness, Anxiety, Upset Stomach, Mood Swings, Rapid Heart Rate, Hallucinations

Side effects are rarely reported for doses up to 400 mg, but may appear more commonly at much higher doses.

Endogenous Hordenine

Hordenine, also known as N,N-dimethyltyramine, is a normal part of human metabolism. In humans it is created in vivo from tyramine by means of dimethylation.


LD50: 2,000 mg orally in dogs (size and type of dog unspecified); 113.5 mg (route of administration unspecified) in mice.[2]

Half Life

24 minutes in horses after injection (because of rapid MAO-B metabolism). Human information is lacking.

Chemical Properties

Synonyms: Anhalin; Anhaline; Cactine; Eremursine; Hordenin; Hordetin; N,N-Dimethyl-2-(4-hydroxyphenyl)ethylamine; N,N-Dimethyl-4-hydroxy-beta-phenethylamine; N,N-Dimethyl-p-hydroxyphenethylamine; N,N-Dimethyltyramine; Ordenina; Ordenine; p-(2-Dimethylaminoethyl)phenol; p-[2-(Dimethylamino)ethyl]phenol; Peyocactine; Phenol, 4-[2-(dimethylamino)ethyl]-; Phenol, p-[2-(dimethylamino)ethyl]-; p-Hydroxy-N,N-dimethylphenethylamine;
PubChem Compound ID: 68313
Molecular Weight: 165.2322 [g/mol]
Molecular Formula: C10H15NO
XLogP3: 2.1
H-Bond Donor: 1
H-Bond Acceptor: 2
IUPAC Name: 4-[2-(dimethylamino)ethyl]phenol
InChI: InChI=1S/C10H15NO/c1-11(2)8-7-9-3-5-10(12)6-4-9/h3-6,12H,7-8H2,1-2H3
Canonical SMILES: CN(C)CCC1=CC=C(C=C1)O

1. Barwell CJ, Basma AN, Lafi MA, Leake LD;
Deamination of hordenine by monoamine oxidase and its action on vasa deferentia of the rat; School of Pharmacy, Portsmouth Polytechnic, Hampshire, UK; J Pharm Pharmacol. 1989 Jun;41(6):421-3; PubMed PMID: 2570842
2. James A. Duke, Mary Jo Bogenschutz-Godwin, Andrea R. Ottesen;
Duke's Handbook of Medicinal Herbs of Latin America; Page 416; CRC Press, 2009; ISBN 1420043161, 9781420043167
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