Alcohol’s impairment of women’s working memory varies across the menstrual cycle

Alcohol’s negative effect on women’s working memory is somewhat mitigated when their oestrogen levels are higher, a novel study suggests. The findings imply that phases of the menstrual cycle may influence women’s vulnerability to the acute effects of alcohol on certain cognitive functions.
Behavioural endocrinology studies in women suggest that higher circulating levels of the ovarian sex hormone oestradiol (E2) may be linked to better working memory performance, especially under conditions of cognitive impairment (e.g., age-related cognitive decline). Phases of the menstrual cycle characterised by different levels of E2 may, therefore, influence the degree to which women are vulnerable to the acute impairing effect of alcohol on working memory.
In a study published in Alcohol: Clinical & Experimental Research, investigators at the University of Kentucky explored alcohol’s impact on working memory across phases of the menstrual cycle characterised in part by varying levels of oestradiol
75 women aged 21–34 years who consumed alcohol at least once per week but did not meet criteria for alcohol use disorder and were not using hormonal birth control participated in the study. They reported their alcohol consumption over the previous month.
In a laboratory setting, each participant completed two testing sessions scheduled according to their menstrual cycles. The first session occurred during the early follicular phase (days 4–7 of the menstrual cycle), typically near the end of menstruation. The second session took place during the late follicular phase (days 11–14), when oestradiol levels increase in preparation for ovulation. During each session, they consumed either an alcoholic or placebo beverage, completed a series of cognitive tests, then consumed the alternate beverage and repeated the tests.
Participants completed computerised working memory tasks and a pegboard test to assess motor coordination. Hormone levels were measured using saliva samples, and blood alcohol concentration (BAC) was assessed with a breathalyser. Additionally, participants self-reported their levels of intoxication, stimulation, and sedation following beverage consumption. The associations among alcohol intake, menstrual cycle phase, and cognitive performance were examined.
Working memory performance was impaired under alcohol relative to placebo at both the early and late follicular phases of the menstrual cycle. However, as predicted, the magnitude of this impairment was significantly less pronounced during the late versus early follicular phases.
Women are less vulnerable to the acute impairing effect of alcohol at the late follicular phase of the menstrual cycle when ovulation occurs, possibly as a function of heightened levels of circulating E2. Considered in the context of the broader literature, these findings provide novel evidence to suggest that specific phases of the menstrual cycle may differentially affect women’s sensitivity to the acute effects of alcohol on certain cognitive functions. Further research is needed involving women using hormonal birth control or hormone therapy and postmenopausal women, the authors comment.
Source: McGarrigle WJ, Griffith AK, Martel MM, Fillmore MT. Menstrual cycle phase affects alcohol impairment of working memory, Alcohol: Clinical & Experimental Research, 2025.