The 5 Toxic Additives Hiding in 80% of Supplements (and Why I Avoid Them)

When you’re building a daily supplement stack, you’re usually doing it to support your vitality or prepare your body to handle daily stressors. But there is a hidden irony in the wellness industry: the very capsules meant to support our health are often delivery vehicles for toxic additives and contaminants.

While we focus on the "Active Ingredients," part of the label, the "Other Ingredients" list (usually in tiny, faded print) contains compounds that may be actively sabotaging your health. Many of these are restricted in the EU but remain "Generally Recognized as Safe" (GRAS) in the US, despite growing evidence that they accumulate in our tissues and can eventually cause harm.

These fillers are obstacles to your health and should not be included in your diet, in supplement form or in food (in my opinion). This article covers some of the usual suspects hiding in your cabinet, and the research about each that should concern you.

Keep in mind this article is being provided for educational purposes only, and is not medical advice. Please consult with a trusted healthcare provider for advice pertaining to your specific needs and situation. 

Why the "Low Dose" Argument Doesn’t Work

The standard industry defense is that these additives are used in "minuscule amounts" that don’t cause any harm (in their study that only monitored participants for a few weeks). However, many of these compounds are not found in nature, and in many cases, our bodies do not have a process for excreting them, which can lead to accumulation. Small amounts of these compounds may not be a big deal every now and then, but over time the cumulative effects are noticeable. If you take five supplements a day, every day, for ten years, you aren't getting a "low dose", you are literally conducting a long-term experiment on the cumulative effects on your internal organs.

Additionally, unlike naturally-occurring nutrients found in food, many of these synthetic particles are made to be nano-sized. Nano-particles are small enough to cross biological barriers (like the blood-brain barrier) and deposit in your bones, liver, kidneys, and spleen. This is particularly a concern when combined with chemicals like Polysorbate-80 (commonly found in commercial ice creams, vaccines and other meds) which is known to OPEN the blood-brain barrier, allowing these toxins to get into our blood, and accumulate in the sensitive tissues of our brains.

How is This Allowed??

When supplements and drugs are tested, typically the studies are relatively very short term (like as in a few weeks or months long, at most), and often cannot be replicated, meaning that if someone where to do the study over again as written with different people, the results would be totally different. If a study’s results can’t be replicated, this indicates that the scientific method was not followed.

Source: Dr. Neal Smoller, “The 14 Mega-Corporations that Own Your Supplement Brands.” March 30, 2018. https://drnealsmoller.com/rant/the-14-mega-corporations-that-own-your-supplement-brand/

It’s amazing to me that this is standard practice, but unfortunately most supplement companies are owned by large corporations who have more allegiance to their shareholders than the safety of the people consuming their products (AKA “Shareholder Primacy” or “Shareholder Maximization”). I think this explains why most supplement brands, personal care products, infant formula, packaged foods and household goods test positive for heavy metals these days (there is no safe level of heavy metals since they cannot be easily excreted by the body and most of them cause brain damage). This has continued despite increasing awareness because incorporating manufacturing practices that eliminate these harmful contaminants is expensive, which is not generally in the best interest of shareholders unless the company is losing money due to their lack of safety precautions. Our main avenue of enacting change in this area is to vote with our dollars and buy only products that are safe.

How to Avoid Contaminants in Supplements

Since contaminants are harder to avoid than the additives listed on the label, I recommend getting a certificate of analysis (COA) from the supplement manufacturer, (ideally from a third party lab) that tests for heavy metals and other common contaminants. You’ll be able to tell which companies care about yourh health as those are the ones who are proactively sharing this information on the product page.

And now for some of the commonly used additives that are deliberately included in most supplements:

1. Titanium Dioxide (E171)

Used for: Whitening and coating tablets to make them look "clean." Also used in a lot of cosmetics to block UV radiation or add a white pigment.

The Risk: In 2021, the European Food Safety Authority (EFSA) declared it was no longer safe due to concerns about genotoxicity (AKA DNA damage). DNA damage is an issue because if a cell with damaged DNA replicates, that new cell (and all of its descendants) may not function normally. These kinds of issues can devolve into cancers and other disease over time.

My Take: When you ingest these particles, they create oxidative stress and inflammation in the gut (in addition to the DNA damage). Since our gut is strongly linked to our mental health, assimilation of nutrients and pretty much every other bodily process, avoiding any stress and inflammation in this area, is something I prioritize. Animal studies (PMID: 28106049) showed that even "food-grade" doses led to immune signaling disruption and pre-cancerous lesions in the colon.

2. Silicon Dioxide (Silica)

Used for: An anti-caking agent that keeps powders flowing through factory machines.

The Risk: Often marketed as "natural" because there is a natural form of silica that exists in nature (and is even a constituent in some medicinal herbs). But the stuff in your vitamins is synthetic amorphous silica, which is not the same thing.

The Research: Long-term mouse studies (PMID: 31701056) found silica deposits in the kidneys and liver, leading to chronic low-grade inflammation. For those of us focused on kidney health and filtration, these "nano-clumps" are a needless burden on the body’s detox pathways.

3. Carrageenan

Used for: A thickener in gummies, liquids, and "vegetarian" softgels. This is also added to many foods including heavy cream, baked goods and Costco rotisserie chicken.

The Risk: Derived from seaweed, so it sounds natural, but it’s actually highly processed. Carrageenan is a known gut irritant and is actually used in animal studies to cause inflammation so as to test anti-inflammatory therapies.

My Take: Carrageenan is notorious for triggering TLR4 inflammatory pathways. So if you’re someone who’s dealing with "leaky gut", digestive issues, or endotoxin issues, eating carrageenan is kind of like throwing kerosene on a fire. A 2025 review (PMID: 40195700) confirmed its role in microbiome disruption.

4. Artificial Colors (Red 40, Yellow 5, etc.)

Used for: Purely added for aesthetics.

The Risk: Most of these food colorings are petroleum-derived chemicals. They’ve been linked to hyperactivity in children and contain contaminants like benzidine (a carcinogen).

The Research: Red 40 has been shown to disrupt the p53 tumor suppressor pathway, which is your body’s "guardian" against rogue cell growth (PMID: 37719200). There is zero biological reason to ingest petroleum dyes for a "wellness" benefit.

Alternatives: Instead of artificial colorings, try using high-pigmented fruits and vegetables to color your foods. You can buy powdered beets (red/pink), spirulina (green), butterfly pea flowers (blue), turmeric (yellow), and create the entire rainbow without any toxic additives.

5. Magnesium Stearate (and Stearic Acid)

Used for: A lubricant to prevent capsules from sticking to metal machinery.

The Risk: While often claimed to be safe, it is frequently derived from low-quality seed oils (hydrogenated oils/PUFAs) like cottonseed or palm oil.

My Take: We want to minimize unsaturated fats and "flow agents" that can create a biofilm in the gut, potentially hindering absorption of the active ingredient in the supplement you’re paying for. While the stearic acid itself is a saturated fat, the source and the processing (potential pesticide residue in cottonseed) make it a "hard pass" me.

How to Find "Ivy-Approved" Supplements

Once you start reading labels, you can't "un-see" these additives. They are in 80% of the products on big-box shelves. If we want to start actually healing, we need to demand better.

• Look for "Excipient-Free": Some high-end brands now use L-Leucine (an essential amino acid) or organic rice concentrate as flow agents instead of silica or steroids.

• Food-Based Supplements Over Synthetic: Supplements are an ultra-processed food, but you can reduce the risk of toxic contaminants by opting for food-based supplements over the synthetic ones made in a lab. Vitamin C supplements from acerola cherry, for example, are less likely to include harmful additives compared with the synthetic ascorbic acid versions.

• The Capsule Matters: Opt for "Pullulan" capsules (naturally fermented tapioca) over carrageenan-heavy "veggie caps" or gelatin if you know the source is high-quality.

• Trust Your Eyes: If a supplement is neon green or bright red, this can indicate synthetic dyes have been used. Nature’s colors are a lot more earthy and muted in comparison.

• Powder Over Pills: When in doubt, buy the raw herb or the pure powder and make the capsules yourself. This is time consuming, for sure, but it’s harder for manufacturers to hide titanium dioxide and these other additives if you buy the bulk powder and make the capsules yourself.

Are there any brands that don’t use these additives?

There are a few brands that mostly avoid them, but it’s hard to find anyone who is consistently following good practices. I think we all need to get used to doing our own research and actually just read the ingredients label. We can shape what future products are developed just by changing our buying habits. I feel weird endorsing any particular supplement brand because policies can change.

My advice: check all products individually. Even if a brand is generally pretty good about not including these additives, different supplements from that same brand are likely sourced from different areas of the world and may have different additives as a result.

The Bottom Line

Your health is an investment. Don't let a "clean-looking" bottle or holistic-sounding marketing tactics fool you! Always read the fine print and keep your engine free of synthetic sludge. Also be aware of who owns the company that is making the supplement and search out small, family-owned businesses as those are the people who actually care about your health, not increasing profits for their shareholders.