What are the side effects for using minoxdil? I got a headache when used it. Is this safe long term?

Thanks for your query. Minoxidil side effects generally include allergic reaction, dry scalp, dandruff like particles, headache, burning , itching. If any of the above happens, then you should consult your doctor. All The Best

Typical side effects of using Minoxidil include dry itchy scalp, flakiness, burning irritation.  Be sure to read the directions and do not use too much to avoid systemic absorption as this can lower blood pressure and you may experience vasodilation and headaches. 

If you are getting headaches from minoxidil that means that some of the medication is being absorbed. As you may know, minoxidil treats and lowers blood pressure and that could cause headaches