Not losing hair but want finasteride

Im looking to restart fin at this dose and was wondering if it’ll be effective at maintaining/thickening my current hair. I’m not looking for regrowth as i haven’t actually lost any hair yet, but my non-donor area hairs are way thinner in comparison. I previously took .25mg every other day for 5 and 1/2 months and i don’t think it did anything. Hard to say if this dose was too low or if i got off too early.

If you think about it, 0.25 mg is 50% as effective as the full 1mg dose of finasteride. Some men with less severe hair loss may respond to this lower dose while others may not. If you haven’t lost hair, why are you on the drug at all?