My husband uses the liquid eye dropper and I want too
from the history you provided, are you currently using minoxidil as well? What strength are you using if you are currently using it? Have you seen a hair restoration surgeon prior to starting minoxidil? to answer your question, I usually recommend 5% minoxidil to my patients, and have couples that share their minoxidil. So yes, you can use your husband's minoxidil, just be cognizant of what % he is using vs the % you are using. Increasing the % of minoxidil can cause shedding in the first couple weeks of use.
I actually encourage women to use 5% minoxidil. However, since minoxidil works to reset the growth cycle, you'll likely notice some shedding when you begin. Perhaps start by using it every other day and then working up to daily after a few weeks. The recommend usage is 2x per day.