I take 20mg lisinopril but my bp is still 140/70 what should i do or try?

Here ya go: For someone who is 26 and has a BP of 140/70 there are several points to do 1) Healthy lifestyle A. Diet, low sodium B. Exercise to lose weight in case you have to 2) Lisinopril 20mg might not be enough and you will need to increase to 40mg daily 3) If one medication is not enough then 2 or 3 medications might be needed

Lifestyle changes: New guidelines (JNC 8) would say you're at goal and therefore the med is working fine. But at your age you should be concentrating on making sure you've done what you can to control your BP through life style modification - diet, exercise, weight loss and a big one for young men: make sure you're not drinking in excess.