I was prescribed citalopram, 20mg daily. but i was taking 80mg of ginkgo biloba for just 3 days, prior to this. when can i safely start citalopram?

Gingko biloba: The elimination half-lives of the most active constituents in gingko (gingkolide a ; b, and bilobalide) are 2-7 hours. This means they would be effectively gone from your system in 24-35 hours. You could probably start your prescription citalopram today, if you want to. http://www.mskcc.org/cancer-care/herb/ginkgo.

5x7hours: Gingolideb has the longest half life of the constituents tested. It's half-life is seven hours. Therefore we calculate five half-lives as the clearance point for the medication. You should then safely be able to start citalopram 35 hours after your last dose of ginkgo biloba.