5 Things to Consider Before Taking a Supplement


Around 77% of Americans take one or more nutritional supplements, and the number of people popping supplements is on the rise. Some of the most popular are supplements for heart and immune health. Supplement taking is highest in middle-aged men and women.

But not everyone who takes one or more supplements does it for the right reasons. Some buy a new supplement because a friend recommended it, or because they saw a catchy ad that pointed out its potential benefits. Don’t let advertising sway you!

If you’re considering a supplement, it’s smarter to do your research and know the science behind taking a particular supplement rather than trusting an ad or a recommendation from a friend. Here are five things you should consider before purchasing your next supplement.

Know Why You’re Taking It

Do you need a supplement because you have a health condition or you’re at high risk for one? Make sure there’s enough evidence to support its benefit. Look for valid studies that show its safety and effectiveness and watch where you get your information from. Use reputable sources like MedlinePlus, the U.S. National Library of Medicine’s site.

Also, not all studies are created equal. Some of the studies in reputable journals that show benefits were carried out in cell culture or on animals rather than human beings. Some may be studies that only show a correlation between a particular vitamin, mineral, or supplement and some outcome and don’t necessarily show the supplement caused the outcome.

The best studies are randomized controlled, double-blind trials, as they show causation rather than correlation. Reputable sites, like Mayo Clinic or the Cleveland Clinic, also provide unbiased information about certain types of supplements. Check these sites before buying a new supplement.

Most importantly, discuss the supplements you’re taking or plan on taking with your physician. They know your medical history and are a better judge of whether they’re right for you. A supplement can work well for some people, but not for others. Their experience may not be the same as yours.

Consider the Other Supplements and Medications You’re Taking

Supplements can interact with each other, with other nutritional supplements, and with prescription medications. For example, some supplements, like garlic or omega-3s, are unsafe if you’re taking a blood thinner. Always consult your physician before starting one. Like medications, supplements can have side effects. Use the same level of caution when buying a supplement as you would a prescription medication.

Keep this in mind too; supplements do not have to be approved by the FDA (Food and Drug Administration) before reaching the market. They can be on store shelves without undergoing extensive testing, as prescriptions do, and without proof that they’re safe and effective.

Supplements May Not Contain What’s Listed on the Label

Independent testing of supplements by sites like Consumer Lab often reveals discrepancies between what’s listed on the label of a supplement and what’s in the product. A supplement may contain more or less of an active ingredient, and some contain none of the active ingredients at all!

Harvard Health Publishing points out one example. After independent testing of three memory supplements, two contained none of the active ingredient and the third contained ingredients not listed on the label that could be harmful.

That’s the drawback of lack of regulation; it’s up to the manufacturer to ensure they produce a pure product with the appropriate quantity of the active ingredient, yet they’re in it to make a profit. Some cut costs to increase their profit margin and may use less of the active ingredient than is listed on the label.

One way to increase the odds of buying a pure product and one that’s as potent as it says is to look for products that have a “seal of approval.” Independent laboratories test these products to ensure they contain what they say. However, they say nothing about whether the ingredients are safe and effective. Before buying a supplement, check the FDA’s website and make sure the supplement doesn’t have ongoing safety issues or recalls.

Supplements Aren’t a Substitute for a Healthy Diet

When a vitamin, mineral, or phytonutrient is in a food, it comes with a food matrix, a plethora of other compounds that may include other vitamins, minerals, fiber, phytonutrients, and more. In some cases, these components work in synergy to offer their health benefits. Taking an isolated component won’t always have the same benefits as getting that component in food form with the matrix intact.

It sounds easy to pop a pill to get your nutrients, but it’s wiser to use supplements as a “fill in” for nutrients missing from your diet or that you’re unable to get enough of. For example, vegans must get vitamin B12 from a supplement since plant-based foods don’t contain this B-vitamin. If you don’t get enough sun exposure or live in an area with little direct sunlight, you might need a vitamin D supplement. Otherwise, see if you can fulfill your vitamin and mineral requirements with food first.

Supplements Can Have Unexpected Side Effects

Although supplements have a decent safety record, they can have unexpected side effects, especially if you take more than the recommended amount. For example, over 60 cases of liver failure worldwide are linked to taking green tea extract. Yet studies suggest that drinking green tea has a variety of health benefits. So, isolated ingredients in supplements may behave differently than the same component within the context of food.

The Bottom Line

Know why you’re taking a supplement, do your research, and choose a reliable source. It’s like the wild, wild west for supplement makers with little regulation or assurance that what they produce is safe and effective. That means it’s up to you to choose products that offer benefits but also cause no harm. Do your homework before supplement shopping and think before you purchase. Cover these angles and you’ll have more confidence in the supplements you take.



  • CRNUSA. Org. “Dietary Supplement Use Reaches All Time High”
  • CBC.ca. “Health Canada toughens green tea extract warnings”
  • Harvard Health Publishing. “What’s in your supplements?”


Related Articles By Cathe:

Why Supplements Can’t Match the Health Benefits of Real Food

Supplements Have Potential Risks and These Types Are the Worst

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

Why Whole Foods Are Better Than Supplements

Are Probiotic Supplements Overhyped?

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

6 Vitamins and Minerals You Should Think Twice Before Taking as a Supplement

Calcium: the Supplement You May Not Need for Healthy Bones

6 Health-Saving Facts You Should Know Before Taking Supplements

Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos and Free Weekly Newsletter. Here are three ways you can watch and work out to my exercise videos:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy