3 Types of Supplements You Should Think Twice Before Taking

image of nutritional supplements in capsules and tablets

Supplement use is on the rise. According to a survey conducted by the Council for Responsible Nutrition (CRN), 71% of adults in the United States takes one or more supplements. Why are supplements so popular? People see them as a way to potentially slow the aging process, lower the risk of disease, help with weight control, or compensate for a less than ideal diet.

Some supplements, assuming you buy them from a reputable source, are unlikely to be harmful, but there are certain classes of supplements that carry risk, especially if you buy from a disreputable supplier. To illustrate the scope of the problem, the Poison Control Center gets a call every 24 minutes, on average, from a bad reaction related to a supplement – and keep in mind, most people don’t call the Poison Control Center when they have a reaction, so the scope of the problem is probably larger.

In fact, when the Drug-Induced Liver Injury Network compiled data over a 1-year period, 839 people suffered liver injuries and 130 of those cases were due to supplements, including herbals. One reason is some supplements contain ingredients not listed on the label. Some of the contaminants the FDA has identified in supplement products include anabolic steroids, peptide hormones, prescription weight loss medications, and clenbuterol, a medication used to treat asthma that also promotes muscle growth. But, the risk is higher with certain supplements. Let’s look at a few you should either avoid or research carefully before taking.

Weight Loss Supplements

As you know, there are no magic supplements that guarantee weight loss, despite the empty promises that supplement manufacturers spew out. Weight loss supplements are frequently formulated with herbal stimulants, but the FDA has also confiscated products that contain actual drugs with amphetamine-like activity. In fact, the FDA has confiscated a number of weight loss supplements with the prescription drug sibutramine, a medication that has since been withdrawn from the market.

Even weight loss supplements that contain only herbal stimulants can cause unwanted symptoms like a rapid heart rate, sweating, and an elevation in blood pressure. They also may not be safe if you have hypertension or heart disease. Also, keep in mind that weight loss supplements don’t lead to healthy, sustainable weight loss. Think twice before taking any type of weight loss supplement. It’s easy to see why weight loss supplements top the list of those to avoid.

Bodybuilding and Exercise Supplements

There’s no shortage of supplements that claim to help you get lean and ripped. However, bodybuilding supplements may contain more than what’s stated on the bottle.  In fact, a study published in 2008 suggests that adulteration and contamination are fairly common with supplements that cater to the desire to build muscle. Of the non-hormonal supplements researchers analyzed, some of which were bodybuilding supplements, 15% contained anabolic steroids. Another study, funded by the Olympic Committee, tested 245 supplements. Of those tested, almost 19% contained steroids. A 2007 study also analyzed 54 supplements and found 11% contained stimulants. The dangers? Steroids have the potential to damage the liver and kidneys, raise blood pressure, increase the risk of stroke, and cause mental health issues.

Herbal Supplements

Herbal supplements might sound harmless, but you aren’t always getting what’s on the label. One way that researchers identify what’s in a supplement is with DNA barcoding, a procedure that aids in the identification of what plants are in a product. Unfortunately, a study found that 59% of the products tested contained plant species not listed on the label. Another red flag. A study of supplements sold at well-known retailers including Walmart, Walgreens, Target, and GNC showed that one in four of the supplements tested, including many herbal supplements, didn’t contain the active ingredient listed on the label in any quantity. What they contained, instead, was plant-based filler. What’s concerning is some people could be allergic to the plant species added to these products or the plant could interact in a dangerous way with prescription medications.

Why Is This Problem So Common?

Unlike prescription medications, the FDA does not evaluate or test supplements before they enter the market. The responsibility is solely on the manufacturer to ensure the products they produce are safe and contain the ingredients they claim. In the name of profits, a supplement maker might cut corners by including less of the expensive active ingredient or replace it with a cheaper, plant-based filler. To make a product more effective, as in weight loss or bodybuilding supplements, they could add stimulants to promote weight loss, including prescription ones, or anabolic steroids to promote muscle growth, all without your knowledge.

Guidelines if You Take Supplements

  • If you take supplements of any type, here are some guidelines for doing it safely:
  • Know who you’re buying from. There are sites online, such as Consumer Lab, that independently test supplements and publish the results. Also, look for a USP verified seal on supplement products. This seal indicates that the quality and contents have been verified by the U.S. Pharmacopeial Convention. Unfortunately, this only applies to non-herbal supplements.
  • Have a valid reason for taking a supplement. Don’t base your decision on clever advertising that promises quick weight loss, more energy, or some other compelling promise that’s often not backed by research. First, ask your healthcare provider their opinion and then do your own independent research to learn more about the mechanism of action and potential side effects.
  • Don’t use a supplement to treat a symptom that you don’t know the cause. See your healthcare provider if you’re having health issues.
  • Stay away from supplements that make promises that sound too good to be true and aren’t supported by science.



CRNUSA.com. “Supplement Use Among Younger Adult Generations Contributes to Boost in Overall Usage in 2016—More than 170 million Americans take dietary supplements”
J Mass Spectrom. 2008 Jul;43(7):892-902. doi: 10.1002/jms.1452.

Hepatology. 2014;60(4):1399-408.
FDA. “Beware of Products Promising Miracle Weight Loss”
ConsumerMedSafety.org. “Liver injuries from herbals and dietary supplements have led to death and liver transplants”
Men’s Health. “Who’s Spiking Your Supplements?”
Vopr Pitan. 2013;82(6):6-13.
U.S. Anti-Doping Agency. “Vitamins, Minerals, and Other Supplements”
National Institute on Drug Abuse. “What are anabolic steroids?”
Science Daily. “Analysis of herbal products shows contamination is common”
PopularScience.com. “The troubling truth about vitamins and herbal supplements”


Related Articles:

6 Health-Saving Facts You Should Know Before Taking Supplements

4 Reasons Supplements Aren’t Always All They’re Cracked Up to Be

The Problem with Probiotic Supplements: Are They What They Seem to Be?

Do the Supplements You’re Taking Really Contain What You Think They Do?


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