How long would it take testosterone levels to return to normal after they were dropped from tagamet (cimetidine)?

Reversible: The reduction in testosterone that can occur with Cimetidine is caused by a reversible antagonism of testosterone synthesis - which means that if you are affected by this, then as soon as the drug is out of your body, your testosterone levels should return to previous levels. A level checked 2 weeks after stopping Cimetidine should be at your baseline.