Not All Supplements Are Created Equal

Written By Jeanette De Caro, FNTP, BCHN®, MRWP
Natural supplements

Think the same supplement from different brands are the same? Here are 5 reasons why they are not.

As a Functional Health and Nutrition Practitioner, one of the most common questions I hear is, “Can’t I just grab my supplements at CVS or Costco?”

Ideally, we would get all the vitamins, minerals, and nutrients we need from food. But in today’s world, that’s not always realistic. Even with a healthy, whole-foods-based diet, many people still fall short. Industrial farming practices have depleted our soil, water sources are increasingly affected by pollutants and chemical runoff, and the modern food supply is flooded with processed and ultra-processed options that offer plenty of calories but little nutritional value.

In addition, many people face chronic health conditions that increase nutrient needs. Autoimmune diseases, hormonal imbalances, digestive issues, stress, and certain medications can all interfere with how the body absorbs and utilizes nutrients. Environmental toxins, including exposure to BPAs, herbicides, pesticides and more, further compound the problem.

Supplements are not a replacement for real food, but they can play a vital role in helping the body heal, restore balance, and function at its best.

This is one area where quality, sourcing, and manufacturing standards make all the difference.

1. The Supplement Industry Is Loosely Regulated

Unlike pharmaceutical drugs, which must pass FDA scrutiny, dietary supplements are regulated more like food. Manufacturers are not required to prove safety, efficacy, or even labeling accuracy before a supplement hits the shelves.

While the FDA does set some manufacturing guidelines known as Good Manufacturing Practices (GMPs), enforcement is minimal. This allows for significant variability in the potency, purity, and overall quality of ingredients.

Two bottles of "Vitamin D3 5000 IU" may appear identical, but what's inside can vary dramatically.

2. “Made in the USA” Isn’t Always What It Seems

A label claiming “Made in the USA” often refers only to where a supplement was bottled or packaged. The raw ingredients themselves may have been grown, processed, or manufactured in countries with far less oversight.

India and China are two of the largest exporters of raw supplement materials, including herbs, minerals, and synthetic vitamins. In many cases, these ingredients may not undergo the same quality testing or safety evaluations that consumers in the U.S. assume.

3. There’s a Big Difference Between Natural and Synthetic Supplements

Most drugstore vitamins are made with synthetic ingredients because they are cheaper to produce and more profitable for manufacturers. However, that lower price often comes at the expense of quality and effectiveness.

Synthetic supplements have been found to contain contaminants such as heavy metals, pesticides, petroleum byproducts, hexane, and environmental toxins including polychlorinated biphenyls (PCBs) and dioxins. Long-term exposure to these substances has been linked to neurological, hormonal, liver, and immune dysfunction, along with an increased risk of cancer.

In contrast, natural supplements are derived from food-based sources and often include important cofactors like trace minerals and amino acids that enhance absorption and effectiveness. These nutrients are typically more bioavailable, meaning the body can absorb and use them more easily.

Even when a synthetic and natural supplement have the same dose on the label, they may not deliver the same results in the body. For example, the synthetic form of vitamin B12, known as cyanocobalamin, must be converted in the liver before it can be used. Individuals with certain genetic variations, such as an MTHFR gene variation, may have difficulty with this conversion. The natural form of vitamin B12, methylcobalamin, on the other hand, is already bioactive and can be easily absorbed by the body without needing liver conversion, providing more effective support for energy, cognition, and nervous system function.

Similarly, folic acid, the synthetic version of folate (vitamin B9), must be converted into 5-MTHF, the body’s usable form. Many people have impaired conversion, which can lead to deficiency symptoms even when supplementation appears adequate.

Here’s a closer look at some common vitamins and minerals and how the ingredients differ between the natural and synthetic versions::

  • Vitamin B9 (folate)
    Natural version: Methylfolate (5-MTHF, bioactive)
    Synthetic version: Folic acid

  • Vitamin B12
    Natural version: Methylcobalamin (bioactive)
    Synthetic version: Cyanocobalamin

  • Vitamin A
    Natural version: Beta-carotene or retinol from liver
    Synthetic version: Retinyl palmitate

  • Vitamin D
    Natural version: Vitamin D3 (from lanolin or lichen)
    Synthetic version: Vitamin D2 (ergocalciferol)

  • Vitamin C
    Natural version: Extracts from whole foods like acerola or camu camu
    Synthetic version: Ascorbic acid

  • Calcium
    Natural version: Calcium from algae (plant-based source)
    Synthetic version: Calcium carbonate

4. Third-Party Testing Adds a Crucial Layer of Safety

Because supplements are so loosely regulated, manufacturers are responsible for ensuring the accuracy and safety of their own products. This is where third-party testing becomes essential.

Independent laboratories can verify that the supplement contains what it claims, is free from harmful contaminants, and meets quality assurance standards for production.

One study found that 30% of tested multivitamins contained levels of cadmium and lead above regulatory safety limits. While the FDA states that adults should not exceed 10 micrograms of lead per day, no amount is truly considered safe because it can accumulate in the body over time, leading to serious health issues.

In 2015, the New York State Attorney General’s office used DNA barcoding to test herbal supplements from GNC, Target, Walgreens, and Walmart. They discovered that 80% of the products either lacked the labeled herbs or included unlisted fillers like wheat, rice, or houseplants. Some had no active ingredients at all.

When you choose a third-party tested supplement, you're choosing a product that’s been independently verified for quality, accuracy, and safety. It’s one of the best ways to protect your health.

5. Clinical-Grade Supplements Are Designed With Therapeutic Impact in Mind

Supplements sold through practitioners are often referred to as "clinical-grade" or "practitioner-only" because they meet higher standards for formulation, dosing, and absorption. These products are designed with therapeutic results in mind, not just shelf appeal, and typically use bioavailable forms of nutrients, avoid unnecessary fillers or artificial additives, and follow strict quality control measures. Many are also backed by published research, making them more reliable for use alongside treatment plans for chronic conditions, autoimmune issues, and hormonal imbalances.

Working with a practitioner ensures you're taking the right supplement, in the right form and dosage, based on your unique biochemistry and needs.

Cost vs. Value: Why Quality Pays Off

When it comes to your health, cheap supplements are often the most expensive choice in the long run.

  • If a $10 magnesium supplement is poorly absorbed, you’re wasting your money

  • If a $30 supplement causes side effects from fillers or contaminants, you’re harming your health

  • If you get no results from a generic multivitamin, you’ve just lost time in your healing process

Investing in high-quality, targeted nutrients can support your body efficiently and accelerate your wellness journey. The value comes from results, safety, and peace of mind—not the lowest price per capsule.

Why I Recommend Fullscript®

Fullscript is a U.S.-based, secure, online supplement dispensary that only sells verified professional brands:

  • Products are stored in climate-controlled, GMP-certified facilities

  • Every product is vetted for quality and manufacturer standards

  • Clients get therapeutic-grade supplements with practitioner guidance

  • No risk of counterfeit or expired products (unlike on Amazon)

Fullscript is simple to use and you can set up refill reminders directly to your inbox.

Upgrade your supplement routine and get professional-grade supplements—click here to buy supplements.

Sources:

Jeanette De Caro, FNTP, BCHN®, MRWP