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Limited evidenceStress & mood

Phenylethylamine (PEA)

Phenylethylamine is a trace amine marketed as an instant mood and focus booster, but oral PEA is destroyed within minutes by monoamine oxidase B before it reaches the brain. The only supporting human data come from small open-label trials that deliberately combined it with an MAO-B inhibitor.

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What the science says

  • Oral PEA is almost entirely destroyed by MAO-B before reaching the brain Limited evidence

    Phenylethylamine is the preferred substrate of monoamine oxidase B and has a half-life in the body measured in minutes — roughly 5-10 minutes. This is why supplement PEA produces at most a brief flush, warmth or racing sensation lasting a few minutes rather than any sustained effect, and why product labels increasingly pair it with MAO-inhibiting botanicals such as hordenine — a combination that is pharmacologically active but poorly characterized for safety.

  • Antidepressant claims rest on one small open-label trial with selegiline Limited evidence

    The frequently cited human evidence is Sabelli's 1996 open study of 60 depressed patients given 10-60 mg/day PEA together with 10 mg/day selegiline (an MAO-B inhibitor) — about 60% reported sustained improvement over 20-50 weeks. There was no placebo arm, no blinding, and the design cannot separate PEA's effect from selegiline's own established antidepressant activity. No randomized placebo-controlled trial of PEA alone exists.

  • "The love chemical in chocolate" is marketing, not pharmacology Limited evidence

    Chocolate does contain PEA, but the amounts are trivial relative to MAO-B capacity and dietary PEA does not measurably raise brain trace amine levels. Trace amines act on TAAR1 receptors as endogenous neuromodulators at nanomolar concentrations; that basic-science role does not translate into a demonstrated effect from swallowing 500 mg of PEA HCl.

Dosage & safety

Studied doseSupplement labels typically list 250-500 mg PEA HCl per serving; the only clinical trial used 10-60 mg/day, always alongside 10 mg selegiline. There is no established effective standalone dose because no standalone dose has been shown to work.
SafetyShort-term PEA raises heart rate and blood pressure and can cause flushing, anxiety, headache and jitteriness. The serious risk is combining it with any MAO inhibitor — prescription MAOIs (phenelzine, tranylcypromine, selegiline, rasagiline), linezolid, methylene blue, or supplement-sector MAO-inhibiting ingredients — which can precipitate a hypertensive crisis, the same mechanism as the classic tyramine "cheese reaction". Avoid with stimulants, decongestants and uncontrolled hypertension. Not appropriate in pregnancy or with cardiovascular disease. PEA is not a controlled substance and is not banned in sport, but products stacking it with hordenine or other beta-agonists carry contamination and adulteration risk.

How to take it

TimingEffects last minutes — PEA is broken down by MAO-B almost as fast as it is absorbed.
With food?Labels direct an empty stomach, though it makes little difference to a compound this short-lived.
Worth knowingThe only trial that showed anything paired PEA with selegiline; the obvious fix for its short half-life is an MAO inhibitor, and that is precisely the combination that can kill you.

Interactions

With medications

  • MAO inhibitors — phenelzine, tranylcypromine, selegiline, rasagiline, linezolid, methylene blue

    PEA is normally destroyed by MAO-B; blocking that can precipitate a hypertensive crisis, the same mechanism as the tyramine 'cheese reaction' do not combine under any circumstances

  • stimulants and decongestants (pseudoephedrine, amphetamines)

    additive rise in heart rate and blood pressure do not stack them, and avoid entirely with uncontrolled hypertension

With other supplements

  • hordenine, synephrine and other MAO-inhibiting or beta-agonist ingredients

    products combine these deliberately to make PEA last longer, which is exactly the hypertensive-crisis mechanism avoid PEA products containing MAO-inhibiting ingredients

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does phenylethylamine (PEA) improve mood?

The evidence for PEA is limited. Oral phenylethylamine is broken down by the enzyme MAO-B within minutes, and the only supporting human data are an open-label trial that combined it with the MAO-B inhibitor selegiline, with no placebo arm.

How long does phenylethylamine last?

Only minutes. Phenylethylamine has a half-life of roughly 5-10 minutes, which is why PEA supplements produce at most a brief flush or racing sensation rather than any sustained effect.

Is it dangerous to take PEA with MAO inhibitors?

Yes. Combining phenylethylamine with any MAO inhibitor, including selegiline, linezolid, methylene blue or MAO-inhibiting supplement ingredients such as hordenine, can cause a hypertensive crisis. Do not combine them under any circumstances.

Is chocolate's PEA a real mood booster?

No. Chocolate contains phenylethylamine, but the amounts are trivial and dietary PEA does not measurably raise brain trace amine levels.

Scientific references

Where to buy

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