We also are learning that complexities and variables are introduced in their collection, storage and transport. While there has not been much published on herbal drug interactions, they can and do occur. Additionally, there is increasing concern that environmental pollution may contaminate herbs that were once pure and natural. Compounding the confusion and the hyperbole is the odd regulatory niche into which herbs fall. The federal government classifies many herbal remedies as dietary supplements, even though consumers use them as medicine.
Science still has much to learn about botanicals and their effect on human health.
Become familiar with the manufacturer and its quality control standards. Labels should include the herb's scientific name, the amount of active ingredients and plant parts used, the manufacturer name and address, the batch and lot numbers, and expiration date and dosage guidelines. Purchase all herbs from a reliable source. If possible, get advice and information from a trained herbologist. If you have a choice between a pill and a capsule, use a capsule that has no other additives.