Will hair loss medication really make my hair grow?

Since I was young, I haven't had much hair volume, and as I got older, I looked closely at my scalp and noticed I have few hair follicles and thin hair.

So, since I have less hair, I think I have always lived with it as part of my complex.

When I was in my 20s as a working professional, I earned money and visited scalp clinics, but I took the oral medication and hair tonic they provided, and I went once a week for clinic care.

Hair tonic causes oiliness when applied, so I stopped using it, and I didn't see any effects from the oral medication. I also thought that going to the clinic for a certain period was useless, so after some time, I stopped visiting the clinic as well. I have some bad memories related to that.

I've heard that hair loss medication is effective these days. Can I just buy it at the pharmacy? Or can a dermatologist prescribe it for me? I'm also curious if taking it will actually help hair grow.