I use expired petroleum jelly for my eyelashes, is it still effective even though it is expired?

It is never a good idea to use an expired product. Especially around the eyes which are particularly sensitive to irritation. If you haven't had a reaction, great. But I would certainly recommend that you buy a new jar pronto. Best, Dr. Nazarian

Petroleum jelly helps moisturize the follicle and the lashes, making them appear healthier.  Products have use by dates because certain of their components may break down over time.  These degraded substances may cause some unwanted effects like irritation.  It is always best to discard and not use expired products.  Hope this helps!

Petroleum jelly won't help your lashes grow - expired or not. What it will do is moisturize them though, so that they can appear more healthy. But it does not affect the actual growth cycle of the lashes which is what is necessary to make them grow longer, thicker, and darker. "This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."