Does Propecia Work in Cycles?

Is it possible for Propecia to work in cycles? It would be great to get an opinion on my experience:

Month 1-3: Hair felt and looked thicker, barely any falling out or shedding.
Month 4-6: Thinner hair and a lot of shedding. I thought it had stopped working. But then…
Months 7-10: Same feeling as months 1-3, thicker hair and i was excited that the drug was working again.
Now I am in Month 12 and my hairline has never been receded further and I have more scalp visible on the crown than ever.

Is it possible that these are natural hair growth and hair loss phases? I dont know if the drug has just stopped working or will start up again because nobody seems to experience this. Thanks for your help.

Propecia does not work in cycles, but your hair grows in cycles (with or without) the medication. Propecia does not just stop working. It is that everybody responds differently to medication.