Onions are not the most popular vegetables out there. We usually like to serve them in our dishes and, more often, in our salads, but the mere thought of them makes us squint. That is because the strong natural chemicals released upon cutting the onion irritate our eyes and make us ‘cry’.
Other than this, there are no other strong contraindications. It is, however, recommended to avoid external and internal use of onions if you are allergic to them. Also, if you have sensitive skin, it is probably safe to leave onion-based home remedies on for only half an hour. Overnight onion-juice treatments may irritate the skin and lead to unwanted results.