 [ Symptoms ] how long after i take zantac will i begin to feel relief [ Disease ] hopefully when you take zantac or pepcid over the counter type of h2 blockers you should feel some relief within 30 minutes to an hour so once again if you do not feel like it is helping then you could also take possibly an antacid like a maalox or tums or mylanta that would be okay but if you find that that is still not helping in some cases you may need to be referred to a physician or a healthcare provider to have it looked at further you can try one and of course the antacid may have a quicker effect because of the fact that its a liquid so it does not take as long to dissolve as compared to the tablet