Moderate alcohol use by breastfeeding women appears to be relatively common. Alcohol concentrates in breast milk at levels slightly higher than in maternal blood, peaking at 30-60 minutes after consumption. Most studies find no link with the duration of breastfeeding unless drinking is fairly heavy (>2 standard drinks/day). However, seven studies have found that moderate maternal alcohol consumption was associated with a shorter duration of exclusive breastfeeding; one found no difference and one found an increase. Alcohol affects oxytocin release, leading to reductions in breast milk consumption in the following hours. Infant alcohol exposure may increase fussiness and reduce sleep, both temporary if the mother does not continue to drink. These effects on the infant and on the breastfeeding process could be interpreted by mothers as signs of infant dissatisfaction with their breast milk, “insufficient milk,” or other commonly expressed causes for suboptimal breastfeeding patterns. Chronic alcohol consumption, even if moderate, may have a number of more serious effects, including on infant development. In the early weeks or months of life, infant toleration of alcohol is lower than it is at later stages of infancy, and the early breastfeeding process is more susceptible to disruption. Therefore, it may be wise to advise mothers to continue their abstinence from alcohol during pregnancy into the first few months of breastfeeding. Little research has been done on how often women time their drinking so as to avoid infant exposure to alcohol. Health workers and others sometimes propagate myths that alcohol, especially alcoholic beer, is beneficial to breastfeeding. Research is needed in different cultures into whether various forms of cautionary messages are likely to discourage moderate drinkers from initiating breastfeeding or to shorten its duration, and which type of messages if any actually lead to a reduction in drinking during breastfeeding.