Oral minoxidil can aid in reducing hair loss resulting from telogen effluvium (a more temporary form of loss and thinning) and cancer therapies. However, oral minoxidil can cause side effects such as a fast or irregular heartbeat, weight gain, chest pain, shortness of breath, bloating, flushing or redness of the skin, swelling of the feet or lower legs, numbness or tingling of the hands, feet, or face, skin rash, and itching. It can also cause an increase in heart rate or other cardiovascular symptoms. Topically applied minoxidil has an insignificant effect on your blood pressure. However, if you’re taking diuretics or hypotensive medications, it can lead to low blood pressure that causes dizziness or fainting.