Is eyelash serum effective for sparse and droopy eyelashes? Please recommend some products as well.

My eyebrows are sparse and droopy.

So I should apply mascara.

If I don't wear mascara, my eyelashes droop, so it actually feels heavy and uncomfortable.

I'm using mascara.

My younger sibling is telling me to try eyelash serum.

I wonder if applying a lash serum works even for sparse and droopy eyelashes like mine.

Also, I would appreciate it if you could recommend any products you have used that worked well and were satisfied with.