A hairy fall: syncope resulting from topical application of minoxidil.

BMJ Case Rep. 2015 Sep 7;2015. pii: bcr2015210945. doi: 10.1136/bcr-2015-210945.
A hairy fall: syncope resulting from topical application of minoxidil.
Dubrey SW1, VanGriethuysen J1, Edwards CM2.

We describe the case of a young man who developed syncope after using a high strength formulation of topical minoxidil as a hair growth restorer. Other potential cardiovascular and endocrine causes were excluded, and his symptoms resolved on discontinuation of the product. While syncope is a recognised side effect of using this powerful systemic antihypertensive agent, few cases are documented in the literature, which we illustrate in our discussion.

Do you have access to the full text? I've always figured that side effect requires minoxidil applied to a large area of scalp and maybe also baseline low blood pressure.