Actually, the above statement is partly correct and partly incorrect. First, St. John's Wort isn't an OTC med -- that's something like aspirin or Robutussin. St. John's Wort isn't a med, it's a plant, one that comes in many forms such as tinctures, capsules, teas, standardized extracts, etc.. Like aspirin, anything that was in use before the passage of the Food and Drug Act way back when isn't covered by that statute -- that's right, aspirin isn't covered either. And like Tylenol or generics of all kinds or tainted beef, even if something is regulated it isn't actually inspected by anyone very often, so we have many tainted products, and because pharmaceutical companies don't tell FDA the truth about their products, we don't know how safe they are either until they've been in use for many years. Take Tylenol again -- acetaminophen is highly liver toxic, but still on the shelves. St. John's Wort has been used in herbal medicine for centuries, so we're pretty sure it's safe if in its natural form, but it's usually not used in its natural form, it's usually used in a standardized form, which is a little different. But if you look at people who've reported injuries from drugs vs. natural remedies, you'd never take a drug, you'd only take natural remedies. Which is to say, nothing is safe for everyone. Some companies make more reliable products than others, so it's good to have a good local health food store to shop at rather than fishing around on the internet. As to studies, there are hundreds of studies on St. John's Wort, and it's officially recognized in Europe as a safe anti-depressant. But it isn't an anti-anxiety remedy unless your anxiety is caused by depression, which is the case more often than we think. There are many anti-anxiety natural remedies, and for the most part the only real risk is that they won't work -- very few people suffer serious problems from truly natural products, and when they do they're almost always reversible, unlike FDA approved drugs which are approved despite known toxicity.
Over the counter meds haven't been tested in trials so are unreliable. The purity of active ingredient is not guaranteed. CNN article is below.
http://www.cnn.com/2009/OPINION/11/23/frum.supplements.drugs/index.html