How to Shop Smarter for Dietary Supplements

Shopping for dietary supplements can be overwhelming – but it doesn’t have to be.

Supplements are dietary ingredients not intended to treat, diagnose, prevent, or cure a disease. A broad category, these products encompass many ingredients and are offered in many forms.

Selecting the right supplement for your needs can be even more challenging given that the US Food and Drug Administration (FDA) does not regulate them as they would other products. Therefore, much of the research falls on you.

This seems easy enough, right? After all, the dawn of the internet means that we have mass amounts of information at our fingertips at any given moment. Unfortunately, this only makes your task more challenging as you now have to weed through all of the misinformation.

So where do you start? Follow the tips in this article to ensure that you are able to select the best dietary supplement for your needs.

Role of the FDA

While the FDA is charged with regulating everything from cereal box labels to cutting edge medical devices, their role regarding dietary supplements is a bit different. The FDA steps in after a supplement hits the market, rather than before.

This means that manufacturers and distributors of a particular supplement are responsible for ensuring their safety, effectiveness, and proper labeling. These conditions are not always met, however. The FDA takes action only if they discover this to be the case.

Unfortunately, this may occur after you have already purchased and used a supplement. To avoid this issue, your investigation should start with the ingredients label.

Where to Start: The Ingredient Label

Whether you could use more energy, have been experiencing constipation, or simply feel your diet is missing key nutrients, your search for a dietary supplement likely started with a particular need.

When you have identified products that most interest you, you probably wonder if they are safe and effective. These factors are largely related to the information you can obtain from the label.

To ensure FDA compliance, manufacturers must include:

  • a descriptive name indicating that the product is a dietary supplement
  • the name and address of the manufacturer, packer, or distributor
  • an ingredient list
  • the net contents of the supplement


Look for the active and inactive ingredients.

Active ingredients are those that are responsible for the supplement’s actions. Once you’ve identified these, take note, as these will guide most of your research.

Inactive ingredients serve a supportive role such as increasing the absorption or preservation of the product. Though they do not alter the action of the supplement, they can still have side effects.

If you have allergies or dietary restrictions, make sure the supplement doesn’t contain small amounts of milk, wheat, nuts, soy or other products that you typically avoid.

Serving Size, Amounts, and Recommended Daily Allowances (RDA)

Take special notice of the serving size. This can vary depending on the number of pills, tablets, or scoops of powder you’re recommended to ingest each day. The amount of each ingredient is a function of the serving size.

For example, your supplement contains 3g (the amount) of Active Ingredient X in each serving, while a single serving for this product is considered to be 3 pills.

If this information is overlooked and you ingest only a single pill each day, you would be taking in just 1g per serving - perhaps not enough for the desired effects.

Proprietary blends consist of multiple ingredients and can make researching effective amounts of individual ingredients challenging. Again, the FDA requires the label to include only net (or total) amounts. If a 12-ingredient proprietary blend is listed as 4.5g in total, we don’t know the amount of each ingredient included.

The RDA is essentially an average daily level of intake that would meet the nutrient requirements of most (97%–98%) people. This allows you to compare an adequate daily intake to the amount contained in your supplement.

Your supplement may provide 700% of the RDA for vitamin C, for example. In contrast, an ingredient may not offer a substantial amount when compared to the RDA. Depending on the nutrient, ensuring adequate dietary intake or additional supplementation may be necessary.

Also, ingredients may not have an RDA at all. This is often the case for many herbs, extracts, pre- and probiotics, as well as antioxidant blends as daily allowances for these ingredients have not been set.

Recommended Use

This information provides instruction for use. For example, “Take 2 tablets, twice each day, with a meal.” Such a simple sentence actually offers a lot of details that should be followed as described.

If one serving is 2 tablets, taking one serving twice each day means you must multiply the amounts of each ingredient by 2 to get the actual daily totals. Misinterpreting these details can cause you to consume less or more of the target amounts depending on the mix-up.

Important details like consuming with a meal can serve to increase absorption of the supplement, or prevent stomach discomfort. Poor results or unwanted side effects may be avoided by carefully following instructions.

Keep in mind that supplements are offered as tablets, capsules, softgels, gelcaps, powders, and liquids. Each form likely has a specific recommended use.

The Takeaway

Use the label to your advantage. The active ingredients, serving size, and amounts are key components of your research; without these details, you can’t accurately determine safety and efficacy.

Ensure you are using the supplement as recommended. Often times, failure to do so can cause side effects or lower the efficacy.

If any of this information is missing, it is a red flag indicating that this particular supplement is probably not right for you.

The Internet: Best Friend or Worst Enemy?

By reviewing the ingredients label, you can identify key pieces of information that will guide your research. Knowing the active ingredients and their doses is vital.

The internet is an extremely convenient means of researching your supplement, though all of the available information is not valuable. Learning to use it to your advantage is key.

While sites that offer reviews for supplements may be helpful in describing a general overview, they may not be the best resource when it comes down to the nitty-gritty. When you need cold, hard facts, opt for the most objective information.

Tips for Identifying Credible Online Sources:

  • The accuracy of the information offered in each article should be reviewed by a health professional. Bonus points if they authored it.

  • Ensure they’re citing primary sources. This means every reported effect of your supplement is associated with a reference to scientific research.

  • The review should be free of bias. Paid sponsorships and reviews that attempt to sell you other supplements should be avoided. Seek information elsewhere.

The Takeaway

Identifying credible sources that relate complex topics in an objective and easy to understand manner can be challenging.

First and foremost, ensure you’re opting for reviews written or reviewed by a health professional. Avoid those that don’t cite scientific research or have conflicts of interest like paid sponsorships.

Similarly, if the site stands to gain something if you purchase the supplement detailed in their review, the information may be biased.

Research Basics: Types of Studies and Interpreting the Data

The goal of this section is not to turn you into a scientist overnight. Instead, you should walk away with some basic concepts that can help to minimize the risk of selecting a supplement that is harmful or ineffective.

If you are unsatisfied with information obtained from a general review of your product or have had trouble finding reviews that cite primary sources, you may need to dig up the literature on your own.

Dietary supplements are rarely researched as stand-alone products. For example, your favorite protein powder was likely not tested in a scientific study to determine its safety and efficacy.

It is more common that your supplement simply contains individual ingredients that have been tested. Your review of available research can begin with these ingredients.

The best way to go about this is to explore the ingredients in a credible medical search engine. You can use their search bar (just as you would in Google), or take advantage of the guidance offered with the ‘advanced search’ tool.

The following tips will allow you to interpret research on a basic level:

Animal and Human Research

Medications undergo extensive research prior to being offered on the market. This process starts with laboratory and animal testing and finishes with human trials. Dietary supplements do not always follow a rigorous process.

As you are unlikely to try a medication that hasn’t been tested in humans, adopting this policy when it comes to supplements is also a good idea. If your research does not seem to turn up human studies, beware.

Early laboratory and animal investigations may point to promising results that warrant further testing. These models do not ensure the same results in human subjects, however. 

Study Types


Retrospective studies look back in time. The study begins with the known outcome - an illness, for example. Researchers then use medical records to look back in time and try to identify any risk factors subjects may have been exposed to prior to the diagnosis.


Prospective studies are those that follow patients over time. In this instance, the outcome is unknown. The researchers can identify outcomes they are interested in studying, as well as the possible risk factors, prior to starting the investigation.


Another form of a prospective study, randomized, double-blind, placebo-controlled trials is considered the “gold standard” for conducting research as these trials offer the most reliable information.

Randomization ensures patients are assigned to study groups by chance. Blinding means neither the patient nor the investigator has knowledge of which treatment is being offered.

Placebo is “dummy treatment” – though it seems as though you’re administering or receiving treatment, no treatment is actually taking place. In a drug trial, treatment subjects get the actual medication, whereas placebo subjects receive a sugar pill.

This study design is the best means of limiting biases, as well as determining “cause and effect”, rather than only an association.


In a systematic review, researchers use a specific protocol to gather all the available research for a given study question. They use a meta-analysis to compare the results of many similar studies.

When the meta-analysis compares only randomized, double-blind, placebo-controlled trials, it is considered to offer a high level of evidence for a given study question.

Journal Reputation

Unfortunately, even if you have taken steps to ensure you look for the strongest evidence in the most credible search engine, you may still come across studies that aren’t very reputable.

Poor study design and methods, inadequate statistical analysis, and multiple biases can all serve to limit the information presented in the article.

Without having to be an expert at conducting research, there are a couple of details you can easily find to ensure you are receiving good information.

First, look up the medical journal’s impact factor. This number relates to the number of times articles from the journal are cited each year. It varies greatly from journal to journal, and medical specialty to medical specialty, though this chart provides an understanding of where you should be looking.

Investigating the source of funding is another helpful detail. This is often listed at the end of a research study. Randomized trials offer the best information, but they are quite expensive to conduct.

Including sources of funding is required, as this can create biases. For example, a drug company that funds the clinical investigation of their product stands to gain from positive results. This conflict of interest does not mean the results are inaccurate, but it must be disclosed.

The Takeaway

Use credible search engines to investigate your supplement.

A lack of randomized trials with human subjects, studies with poor designs and inherent biases, and publication in less than reputable journals are all red flags.

If these red flags are present in the available research for the supplement that interests you, find another supplement.

Determining Safety and Efficacy

Without being an expert in the research process, it can be challenging to feel confident in what you take away from the results and conclusion of a study.

In addition to the details in the previous section, there are a few tips that can aid your decision.

  • Animal and laboratory studies do not necessarily relate to human studies.

  • Randomized, double-blind, placebo-controlled trials offer the strongest information. Other study designs do not demonstrate “cause and effect”, but may show an association between your supplement and a particular outcome.

  • Studies lasting 2-weeks to 3-months are common; these do not guarantee lasting effects or long-term safety.

  • Pay attention to doses used in the studies and compare them to your ingredient label. You may not see results if most studies used much higher doses than what your supplement offers.

  • While human studies are important, keep in mind that a study in a specific population doesn’t mean the same results will occur for the general population. A supplement that seems successful in obese individuals may not offer the same results on other individuals, for example.

  • Keeping dosing in mind, watch out for the side effects that occurred during the study. Were they mild? Did subjects have to discontinue participation in the study?

Purchasing Tips

If you have identified that a product is safe and effective, there are a number of other factors to consider when purchasing. Keep these questions in mind before you hit the check-out aisle.

Is the seller credible?

  • Do they make claims that aren’t rooted in science or cite biased research?
  • Does their label adhere to FDA guidelines?

What do you get for your money?

  • What are the benefits above and beyond the reported effect of the supplement?
  • Does it offer convenience?
  • Does it contain other ingredients that reduce the need for additional supplements?

Are there similar products available?

  • If so, what ingredients, credibility, and cost do they offer?

Are there natural means of obtaining this supplement?

  • Is it possible to obtain the ingredients and their benefits from your regular diet?

Role of Healthcare Professionals

Your primary care physician should be involved in the discussion prior to the use of any supplement. This conversation can occur before or after you’ve done your research, though it is likely more beneficial to occur after.

You’ll have more specific questions and will be able to offer more specific information. They can interpret research when applicable. The physician’s role is to fill in any gaps and offer guidance.

As they have a large role in managing your care, even if it’s only on routine bases, they can ensure the addition of a particular supplement is safe to include.

The Bottom Line

Use the tips provided in this article to identify the right supplement for your needs. A basic understanding of a few key areas can reduce the risk of selecting a harmful or ineffective product.

Know your label – pay careful attention to the active ingredients, their amounts, and compare them to the RDA. Ensure you understand the instructions for recommended use.

Use the internet to your advantage. Select objective reviews that are free of bias. Similarly, use credible academic search engines.

Make sure your supplement has been extensively studied. Absence of human trials, lack of randomization, publication in low impact factor journals, and multiple biases are red flags.

Safety and efficacy are challenging to determine. Ensure the available research includes long-term testing in human subjects at doses comparable to those offered by your supplement. If these factors don’t exist, it’s best to search for another supplement.

Get the most for your money – to receive the best value, your supplement should be both effective and modestly priced.

Always discuss with your physician before use. If you’ve already done your homework, you’ll likely get the most out of this conversation.

Anthony Dugarte, M.D., C.S.C.S

Dr. Anthony Dugarte is a 2016 graduate of Case Western Reserve University School of Medicine. Passionate about health and wellness, he also has a background in collegiate athletics, exercise physiology, nutrition, and over 10-years of experience as a personal trainer. Most recently, Dr. Dugarte completed a postdoctoral Research Fellowship in Orthopaedic Trauma. At HighYa, he shares the knowledge he has obtained by blending his diverse background with his passion for relating complex health topics practically to a diverse readership. Learn more

How to Shop Smarter for Dietary Supplements