Lisinopril is a long-acting drug. In most adult patients, it starts to work in about an hour, with peak antihypertensive (anti-high blood pressure) effects about 6 hours after taking a single oral dose. For some patients, it may take as long as 2 to 4 weeks of use to achieve optimal results. Since it may take an extended time to see benefit it is important to take this medication every single day (or as prescribed by your physician) not only when your blood pressure is elevated.
