Female hormones accentuate the effect of alcohol Hormones help women chill out faster when they drink alcohol, scientists have found. Researchers have discovered that alcohol makes people relax by stimulating production of a brain chemical produced from the female reproductive hormone progesterone. They believe this is why alcohol tends to have a more rapid effect on women. New Scientist magazine reports that alcohol appears to interact with two brain receptors, one of which, the GABA receptor, is exploited by tranquillisers such as Valium. Animal studies show that stress increases levels of the brain steroid allopregnanolone, which acts on the GABA receptor to reduce anxiety.
Alcohol triggers the release of stress hormones like corticosterone and progesterone.
A team from the University of North Carolina examined whether this also led to an increase in levels of allopregnanolone. They gave rats moderate doses of ethanol roughly equivalent to the amount of alcohol typically consumed at a cocktail party. After 20 minutes the rats given alcohol were found to have dramatically increased levels of allopregnanolone when compared to rats who were given a simple salt solution. To test whether the steroid was responsible for the sedative effect of alcohol, the researchers treated rats with a drug called finasteride, which blocks the formation of allopregnanolone from progesterone. By measuring subsequent brain activity they found that alcohol no longer had the same sedative effect.