With rising herbal medicine sales paralleling a faltering economy, here are some tips from the National Center for Complementary and Alternative Medicine on these dietary supplements:

• Know that herbal medicines aren't as strictly regulated as conventional medicines and that evidence on their safety and effectiveness is often lacking.

• Do your homework. Find out what scientific evidence exists about the product you're considering. A good resource is www.pubmed.gov, an online service from the National Library of Medicine and National Institutes of Health that contains summaries from published research.

• Tell your doctor or other health-care provider any time you plan to use an alternative treatment; recognize that these products can sometimes interfere with other drugs and may even cause dangerous side effects.

• Find out if your health insurance plan covers alternative medicines; many don't.

• Check out the National Center for Complementary and Alternative Medicine's Web site, www.nccam.nih.gov, which contains helpful information for evaluating these products.