Research Only Cognitive & Nootropic

Beta-Endorphin

also known as: b-Endorphin, b-EP, Beta-EP, Endorphin

The body's most potent endogenous painkiller — the 31-amino-acid opioid peptide behind the 'runner's high' and natural pain modulation.

A 31-amino-acid endogenous opioid peptide cleaved from proopiomelanocortin (POMC) that binds mu-opioid receptors with high affinity, producing analgesia, euphoria, and stress modulation — the most pharmacologically active of the endorphin family.

Mechanism of action

Cleaved from the C-terminal region of proopiomelanocortin (POMC) in the anterior pituitary and arcuate nucleus of the hypothalamus. Binds mu-opioid receptors (MOR) with highest affinity (Ki ~1 nM) and delta-opioid receptors with moderate affinity. MOR activation inhibits GABAergic interneurons in the ventral tegmental area, disinhibiting dopamine release and producing analgesia, euphoria, and anxiolysis. Also modulates immune function via opioid receptors on lymphocytes and macrophages.

Primary uses

Endogenous pain modulation (stress-induced analgesia)
Exercise-induced euphoria ('runner's high')
Research biomarker for pain sensitivity and addiction vulnerability
Neuroimmune signaling research

Typical dosing

N/A N/A N/A (endogenous)

Not used therapeutically. Plasma concentrations during exercise peak at ~10-20 pmol/L. Released in response to pain, stress, and vigorous exercise.

Regulatory status

Not approved as a drug. Extensively studied as a biomarker for pain, stress, exercise physiology, and addiction research. Synthetic opioids target the same mu-opioid receptors.

References

[review] Sprouse-Blum AS, et al. "Understanding endorphins and their importance in pain management." Hawaii Med J. 2010;69(3):70-71.
[pubmed] Boecker H, et al. "The runner's high: opioidergic mechanisms in the human brain." Cereb Cortex. 2008;18(11):2523-2531.

Related peptides

Enkephalin

The body's short-acting local painkillers — five-amino-acid opioid peptides that modulate pain, mood, and gut motility at the synaptic level.

Dynorphin

The brain's 'anti-reward' opioid — a kappa-receptor agonist that produces dysphoria rather than euphoria, critical to understanding addiction, stress, and depression.

Dermorphin

⚠ Potent mu-opioid agonist — ~30–40× more potent than morphine; has been misused as a horse-racing doping agent and carries serious overdose/dependence risk. Included for reference and harm-reduction only. Not a therapeutic or "longevity" peptide.

DSIP

An endogenous 9-amino-acid peptide named for its ability to induce delta-wave sleep in early rabbit experiments, with broader effects on stress response, pain modulation, and circadian regulation.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.