3 ms·I've been using the same bottle of toasted sesame oil for at least two years now with no ill effectsby tomjakubowski 3y agoI've been using the same bottle of toasted sesame oil for at least two years now with no ill effectsratsmack 3y agoI keep mine refrigerated.fsckboy 3y agooil rancidity doesn't cause ill effects in general, just off smells and taste. Which, if you don't notice, is fine, the more things taste good to one, the better off one is.