From the UK drinkaware campaign website (government campaign),
http://www.drinkaware.co.uk/check-the-facts/health-effects-o...:
>"The government advises that people should not regularly drink more than the daily unit guidelines of [...] and 2-3 units of alcohol for women (equivalent to a 13% ABV 175 ml glass of wine). ‘Regularly’ means drinking every day or most days of the week."
[175ml is about ¾ cup (USA) and the units above are about equivalent to a single pint of 4% beer]
FWIW If I have 2 glasses of wine I'll be "buzzed" because I don't drink every day. Take a month off from drinking, try two normal glasses (ie not pub measures) and you'll notice.