This is a topically applied medication, so very little of the medication should get into systemic circulation and whole body side effects should be rare. The most common side effects may include: Itching, burning, flaking, dryness, redness, swelling, scaling, hair color changes (usually darkening), scalp skin darkening, or irritation at the application site. In rare cases, chest pain or tightness, dizziness, headache, fast or irregular heartbeat, eye or vision changes, and muscle/joint/back pain may occur. See the Important Safety Information for a full list of potential side effects.