Valerian root powders and extracts are popular herbal sleep aids and may have anti-anxiety effects, but few products on the market provide the amounts of compounds typically used in clinical trials, and some are contaminated with lead, according to a new report from ConsumerLab.com, White Plains, NY. Sales of valerian supplements rose 16.8% to $90 million in 2012, according to Nutrition Business Journal.

Among 10 valerian root supplements ConsumerLab.com recently selected for review, two were contaminated with small amounts of lead—a heavy metal that can impair mental functioning and may affect blood pressure. The amounts of lead found in the valerian root supplements are not likely to cause toxicity alone, but it is best to avoid unnecessary lead exposure.

ConsumerLab.com also measured the amounts of valerenic acids in each product. These compounds appear to be important in determining valerian’s activity on the nervous system and are markers of valerian quality. While all but one product contained the levels expected by ConsumerLab.com from labels, the amounts of total valerenic acids in a suggested daily serving ranged from just 1 mg to as much as 7.2 mg. The amounts of specific valerenic acids, which may have different functions, also varied.

“Valerian may help some people with sleep problems, although the evidence is mixed,” said Tod Cooperman, MD, president of ConsumerLab.com.  “Unfortunately, many people may not be giving valerian a fair try because the brand they buy lacks an effective amount or ratio of key compounds.”