Black cohosh (Actaea racemosa, Cimicifuga racemosa) behaves as a mixed competitive ligand and partial agonist at the human mu opiate receptor
Rhyu MR, Lu J, Webster DE, Fabricant DS, Farnsworth NR, Wang ZJ.
Department of Medicinal Chemistry and Pharmacognosy,
UIC/NIH Center for Botanical Dietary Supplements Research
and Program for Collaborative Research in the Pharmaceutical Sciences,
University of Illinois,
Chicago, Illinois 60612, USA.
J Agric Food Chem. 2006 Dec 27;54(26):9852-7.


Black cohosh is a commonly used botanical dietary supplement for the treatment of climacteric complaints. Because the opiate system in the brain is intimately associated with mood, temperature, and sex hormonal levels, the activity of black cohosh extracts at the human mu opiate receptor (hMOR) expressed in Chinese hamster ovary cells was investigated. The 100% methanol, 75% ethanol, and 40% 2-propanol extracts of black cohosh effectively displaced the specific binding of [3H]DAMGO to hMOR. Further studies of the clinically used ethanol extract indicated that black cohosh acted as a mixed competitive ligand, displacing 77 +/- 4% [3H]DAMGO to hMOR (Ki = 62.9 microg/mL). Using the [35S]GTPgammaS assay, the action of black cohosh was found to be consistent with an agonist, with an EC50 of 68.8 +/- 7.7 microg/mL. These results demonstrate for the first time that black cohosh contains active principle(s) that activate hMOR, supporting its beneficial role in alleviating menopausal symptoms.
Fentanyl and ketamine
Opioids, mood and cognition
Pharmacogenetics of opioids
Black cohosh (Actaea racemosa, Cimicifuga racemosa)

and further reading

Future Opioids
BLTC Research
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Good Drug Guide

The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family