Can I use a hair serum without using a Minoxidil and Aminexil lotion?

Yes, you can use hair serum without minoxidil but it probably will not work to grow hair.  The main active ingredient in these serum that grows hair, is minoxidil.  If you take out the main ingredient, what is the point?

most hair serums use a combination of a monoxidil With some other product. You need to find the ingredients that at used in the serum and if minoxidil is the main Ingredient, you might as well use minoxidil instead. It may be more cost effective. 

The only medication I recognize that works is
minoxidil. The rest is beyond my scope of intelligence. Generally, there are
know ways to treat hair loss and there is NO NEED to invent your own or tie up
to some crazy doctor or clinic that offers bizarre treatments for hair loss.
There are two very effective drugs for hair loss and they are minoxidil and
finasteride (Propecia). Stay main line.