Efficacy	Alzheimer's disease: effective
	Cerebrovascular disease: modest positive effects
	Dementia: modest positive effects
	Memory enhancement: ineffective in adults without dementia
	Intermittent claudication: modest positive effects
	Tinnitus: modest positive effects
Adverse effects	Rare: nausea, vomiting, diarrhea, headaches, dizziness, palpitations, restlessness, weakness, skin rash
Interactions	Warfarin (Coumadin), aspirin, antiplatelet agents, herbal medications such as feverfew, garlic, ginseng, dong quai, red clover, and other natural coumarins
Dosage	120 to 240 mg per day, in 2 to 3 doses
Cost	$15 to $20 per month, depending on brand, for a dosage of 120 mg per day
Bottom line	Safe herbal medication; may be effective for treatment of symptoms of Alzheimer's disease, intermittent claudication, and tinnitus