I have no side effects from Propecia apart from slightly lower libido. Should I continue the medication?

If the side effect you are experiencing is minimal and tolerable I would suggest continuing the Propecia.It is not unusual for the side effects to diminish after several months but if they escalate or become intolerable than I would recommend stopping the medication.

I suggest seeing a hair loss expert now to go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone that work well with propecia. Hair transplantation is an alternative. See an expert. Best, Dr. Emer

If you are comfortable with slightly reduced libido and no other side effect knowing that Propecia is helping you to keep the hair you have, then the decision is easy.  Look at it this way, you are young with many years ahead of you to progress to a higher Norwood class (more hair loss), and if a medication with one tolerable side effect is helping you maintain your hair then I think you have your answer.  Make sure you follow up periodically with a hair restoration surgeon every year or two as new FDA approved medications for hair loss may eventually come to market.

About 5% of patients have issues with Propecia. I do not prescribe it for young males as when there are side effects they are devastating and it takes months to recover. I do recommend Minoxidil and PRP.

There is no yes or no answer here. However the right answer for you can be answered after reviewing your full story with a physician. For many men with aggressive balding in the 20s the answer will end up being yes. Finasteride is the only medication that can have a dramatic effect on the progression of balding into the 30s and 40s.