Skip to Main Content


A 65-year-old man with a history of coronary artery disease, high cholesterol, type 2 diabetes, and hypertension presents with a question about a dietary supplement. He is in good health, exercises regularly, and eats a low-fat, low-salt diet. His most recent laboratory values show that his low-density lipoprotein (LDL) cholesterol is still slightly above goal at 120 mg/dL (goal < 100 mg/dL) and his hemoglobin A1C is well controlled at 6%. His blood pressure is also well controlled. His medications include simvastatin, metformin, benazepril, and aspirin. He also regularly takes a vitamin B complex supplement and coenzyme Q10. He asks you if taking a garlic supplement could help to bring his LDL cholesterol down to less than 100 mg/dL. What are two rationales for why he might be using a coenzyme Q10 supplement? Are there any supplements that could increase bleeding risk if taken with aspirin?


*The industry marketing these materials is replacing the terms "herbal medication" and "botanical medication" with the term "dietary supplement" in order to avoid legal liability and added governmental regulation. For the purposes of this chapter, they are identical.


The medical use of plants in their natural and unprocessed form undoubtedly began when the first intelligent animals noticed that certain food plants altered particular body functions. While there is a great deal of historical information about the use of plant-based supplements, there is also much unreliable information from poorly designed clinical studies that do not account for randomization errors, confounders, and—most importantly—a placebo effect that can contribute 30–50% of the observed response. Since the literature surrounding dietary supplements is evolving and much of it is not peer-reviewed, it is recommended that reputable evidence-based resources be used to help guide treatment decisions. An unbiased and regularly updated compendium of basic and clinical reports regarding botanicals is Pharmacists Letter/Prescribers Letter Natural Medicines Comprehensive Database (see references). Another evidence-based resource is Natural Standard, which includes an international, multi-disciplinary collaborative website, Unfortunately, the evidence available to these objective and unbiased evaluators is rarely adequate to permit clear conclusions. As a result, all statements regarding positive benefits should be regarded as preliminary and even conclusions regarding safety should be considered tentative at this time.


For legal purposes, "dietary supplements" are distinguished from "prescription drugs" derived from plants (morphine, digitalis, atropine, etc) by virtue of being available without a prescription and, unlike "over-the-counter medications," are legally considered dietary supplements rather than drugs. This distinction eliminates the need for proof of efficacy and safety prior to marketing and also places the burden of proof on the Food and Drug Administration (FDA) to prove that a supplement is harmful before its use can be restricted or removed from the market. Although manufacturers are prohibited from marketing unsafe or ineffective products, the FDA has met significant challenges from the supplement industry largely due to the strong lobbying effort by supplement manufacturers and the variability in interpretation of the Dietary Supplement Health and ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPharmacy Full Site: One-Year Subscription

Connect to the full suite of AccessPharmacy content and resources including 30+ textbooks such as Pharmacotherapy: A Pathophysiologic Approach and Goodman & Gilman's The Pharmacological Basis of Therapeutics, high-quality videos, images, and animations, interactive board review, drug and herb/supplements databases, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPharmacy

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.