Side effects include lightheadedness, headache, allergy are most common. Rare heart effects such a cardiac tamponade (life threatening) are found with doses above 2.5mgs but is rare.
Other side effects (taken from Mayo Clinic) for topical applications include:
- Acne at site of application
- burning of scalp
- facial hair growth
- increased hair loss
- inflammation or soreness at root of hair
- reddened skin
- swelling of face
Particularly with systemic absorption either orally or too high a topical dose these side effects include:
- Blurred vision or other changes in vision
- chest pain
- dizziness
- fainting
- fast or irregular heartbeat
- flushing
- headache
- lightheadedness
- numbness or tingling of hands, feet, or face
- swelling of face, hands, feet, or lower legs
- weight gain (rapid)
- Cardiac tamponade