Not All Supplements Are Created Equal: How to Choose the Ones That Truly Work

Every week I’m asked where to buy supplements and which brands to trust. The reality is that the supplement industry is enormous, poorly regulated, and often misleading. While some products are excellent and clinically supported, many others are contaminated, underdosed, or contain substances that are not listed on the label.

What You Don't Know Can Hurt You

You might assume that supplements are harmless because they are labeled as “natural,” but several well-designed studies have shown otherwise. In a 2022 JAMA analysis, the FDA issued warning letters to 31 supplement products that contained illegal stimulants such as BMPEA, methylsynephrine, or DMHA. Only one of those 31 products was recalled, and more than half still contained the banned ingredients when retested six years later.¹

In another JAMA Network Open study, researchers reviewed data from 2007 to 2016 and found 776 adulterated supplements from 146 different companies. Most were marketed for sexual enhancement, weight loss, or muscle building, and many contained unapproved pharmaceutical drugs such as sildenafil, sibutramine, or synthetic steroids. Even after FDA warnings, many of these products remained available for sale online.²

Other studies have shown similar patterns. Reviews from 2023 and 2024 found that between 10 and 30 percent of supplements may contain prohibited or undeclared ingredients, including stimulants and steroid-like compounds. Surveys of sports nutrition products have identified that up to one-third contain substances banned by the World Anti-Doping Agency, sometimes without disclosing them on the label. For athletes this can mean a failed doping test, but for patients it can mean serious health risks or dangerous drug interactions.³,⁴

When “Natural” Isn't Always Safe

When people experience side effects from herbal or botanical products, it is often not because the plant itself is inherently dangerous but because of the way it was processed. Extraction methods, solvents, contamination, or substitution with cheaper ingredients can all lead to toxicity or allergic reactions. In some cases, this has resulted in significant adverse events — including reports of liver failure linked to poorly processed kava and other botanicals.⁵

When Supplements Don't Deliver What They Promise

Even when a supplement is safe, it may not be effective. Many products are formulated or stored in ways that make them biologically inactive long before they reach your system. On the other hand, if you take a supplement and notice no effect at all, that might also be a sign of poor quality. Independent testing has repeatedly shown that many supplements either do not contain the advertised active ingredient or contain amounts very different from what the label states.

A perfect example is probiotics. Many over-the-counter probiotic products have never been tested to confirm that their bacteria actually survive the stomach and reach the colon alive. Without that data, you might be swallowing millions of organisms that are already dead or die in transit before ever reaching their target site. Clinical-grade probiotics undergo viability and stability testing at body temperature and pH, which means you are paying for function, not just marketing.

This issue extends far beyond probiotics. Nutrients like curcumin, omega-3s, and antioxidants all depend on formulation, absorption, and stability. The difference between something sitting on the shelf and something that truly works often comes down to the science behind how it’s made, stored, and tested.

In short, safety and effectiveness depend on BOTH quality and verification.

The Oversight Gap

The FDA does not evaluate dietary supplements for safety or effectiveness before they reach the market. Manufacturers are expected to follow Good Manufacturing Practices, but inspections are limited and enforcement usually happens only after harm is reported. Even after public warning letters, products often remain available for purchase online. This means that a supplement could be contaminated, underdosed, or adulterated and still sit on store shelves or e-commerce platforms for years.

How to Choose Safer Supplements

If you decide to use supplements, it is essential to choose products that are independently verified for purity and potency. Always look for third-party certification on the label. If it is not there, do not buy it. Examples of reputable third-party agencies include:

NSF Certified for Sport applies to products tested for all World Anti-Doping Agency banned substances.
USP Verified means the product has been tested for ingredient identity, strength, and purity.
NSF GMP or Informed Choice certifications confirm that manufacturing facilities follow strict quality and contamination standards.

Proper storage and shipping also matter. Nutrients like probiotics, fish oils, and antioxidants can degrade with heat or humidity. Buying through trusted distributors helps ensure that products are handled and stored correctly.

Be especially cautious when purchasing supplements from large online marketplaces such as Amazon. While the convenience is appealing, many listings are from third-party sellers that the manufacturer has no relationship with. This opens the door to counterfeit, expired, or improperly stored products. Independent tests have found that some supplements sold through online retailers do not match the ingredients listed on their labels. Buying directly from verified manufacturer websites or through your clinician’s office ensures that the product you receive is authentic, safely stored, and traceable.

Why I Choose to Offer Supplements in My Office

When I completed my integrative medicine fellowship, one of the most common questions patients asked was where they could purchase supplements that were safe and effective. After reviewing the research, it became clear that simply recommending people “buy it online” was not good enough.

In my practice, I carry a carefully curated selection of clinical-grade supplements that meet rigorous standards for purity, potency, and transparency. These are the same brands used in research and hospital protocols. They are tested by independent laboratories, free of contaminants and fillers, and distributed through verified channels that maintain appropriate storage conditions.

Having them available in the office also makes it easier for patients to start their plan right away without the extra cost or delay of ordering online and waiting for shipping. I do not sell supplements to generate revenue. I offer them to ensure my patients have access to products that are safe, effective, and trustworthy. When we are working to optimize health, purity and quality matter as much as science.

The Bottom Line

Most supplement reactions or failures come down to quality, not intention. A product might look harmless on the shelf, but if it is adulterated, mislabeled, or contaminated, it can interfere with medications, trigger inflammation, or cause serious harm.

If you take supplements, make sure they come from a transparent and verified source. Look for third-party certifications, clinical evidence, and professional guidance. The goal is not to take more supplements but to take the right ones—safely, intentionally, and with full confidence in what you are putting into your body.

There are so many wonderful herbal and botanical medicines that truly help people. When sourced and used correctly, they can offer powerful alternatives or complements to pharmaceuticals, support the body’s natural healing processes, and improve quality of life. The key is using the right product, at the right dose, for the right person.

References

1. Cohen PA et al. Recalls, Availability, and Content of Dietary Supplements Following FDA Warning Letters. JAMA. 2022;328(3):393–395.

2. Tucker J et al. Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With FDA Warnings. JAMA Network Open. 2018;1(6):e183337.

3. Frontiers in Sports and Active Living. 2023. Prevalence of Adulteration in Dietary Supplements and Ingredient-Mislabeling.

4. Sport Integrity Australia. 2025 Report on Supplements and WADA Compliance.

5. Teschke R. Kava hepatotoxicity—a clinical review. Annals of Hepatology. 2010;9(3):251–265.