My post from 2014 on topical finasteride became one of the most popular ones ever written on this blog. This was not surprising, as literally hundreds of thousands (no exaggeration) of people around the world are nervous about taking oral finasteride and are hoping to switch to or start a topical version as soon as possible. It seems like the topical version will results in fewer side effects and less systemic absorption, although this idea has been debated in the past. Different topical formulations will probably have significantly different levels of systemic absorption depending on technology used.
One can get topical finasteride compounded at any local compounding pharmacy (my own local one said that they fulfill one such request each year). However, hair loss sufferers have for years been hoping for reputable multinational pharmacies or companies to manufacture the product in bulk and sell it globally. In recent years, two entities have taken the lead in making this finally happen: