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Top 11 Food Additives to Avoid In Your Supplements


Do you always check the ingredient label on your supplements?


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Or do you just assume that if it’s a health supplement, it must be safe?

Even though the FDA does not regulate the supplement market, they’ve allowed over 3,000 food additives on their list of approved ingredients[*].

That means all manufacturers have to do is comply with this list in order to receive the green light to launch their product.

But some of these additives are more harmful to your health than you think and shouldn’t ever be used.

That’s why we’ll be exploring the worst offenders when it comes to supplement fillers to avoid in today’s guide. You’ll also learn:

To start, did you know supplement additives go beyond just cheap fillers?

8 Types of Additives in Supplements

When most people think about food additives, what usually comes to mind are cheap fillers, artificial colors, flavors and preservatives.

But this is only a third of the additives supplement manufacturers have at their disposal.

In total, there are eight different types of additives to watch out for when it comes to supplements specifically — and they each have their own distinct properties.

Here’s how they compare:

#1: Fillers

Fillers are by far the most used additives.

As the name suggests, these are added to products to help bulk them up and give them substance.

Oftentimes, the active ingredient is so small it wouldn’t even be noticeable if it wasn’t paired with a filler.

Not only that, fillers usually bulk up a product without jacking up the processing costs, which reduces costs to manufacturers and allows them to sell more volume without increasing expenses in active ingredients.

This means a scoop of your favorite protein powder could contain a lot more fillers and lot less protein than you’re being lead to believe.

#2: Binders

Once again, the name of this additive gives it away: binders help ingredients stay together.

When it comes to supplements, this means keeping your compressed tablet in one piece so it doesn’t crumble before you have the chance to pop it in your mouth.

Binders can also perform double duty and become a form of filler in tablets with small amounts of active ingredients.

The next additive is common in both powdered and tablet supplements.

#3: Anti-Caking Agents (Also Called Flow Agents)

Keeping along the simple name theme, anti-caking ingredients also ensure that your powder doesn’t turn into one giant clump.

But that’s not all they’re good for.

As it turns out, they’re also beneficial for food processing.

Anti-caking agents, also called flow agents, are added to the outside of capsules so they can move through the machines quickly without sticking or snagging on them. And the worst part is they don’t need to be labeled in the ingredient list of the product.

You may not see the big deal in this just yet, but after reading about what these are really made of, you may rethink your stance.

The next two additives serve a better purpose than guaranteeing the capsules make it through the assembly line as efficiently as possible.

#4: Disintegrants

As it sounds, this additive helps break down tablet supplements once they’re in your system.

Anything with the words “fast-acting” slapped on the label usually have a disintegrant additive responsible for this.

#5: Coatings and Glazes

Similar to binders, coatings and glazes function as the glue keeping your supplements together, especially during humid conditions.

But instead of being on the inside, these are on the outside of the supplement.

In the case of an enteric coating, this added layer helps your body break down your supplement at the right time.

This means that instead of being destroyed by your stomach acids, for example, an enteric coating may dissolve slowly so the supplement makes it to your pancreas or small intestine.

#6: Preservatives

Preservatives are another straightforward additive: they help extend the shelf life of supplements so they don’t break down prematurely.

They also keep mold, fungi, yeast and bacteria away[*].

You’ll find natural and artificial preservatives, such as:

  • Vitamins A, C, E and a few amino acids
  • Benzoates
  • Parabens
  • Sulfites
  • Sorbates
  • TBHQ
  • BHA

The artificial preservatives on the list could cause serious damage when consumed in large quantities and over an extended period of time, such as humour disturbances or even tumor growth.

#7: Acidulants

Acidulants are another additive packing more than one purpose.

When it comes to supplements, acidulants can[*]:

  • Enhance the flavor
  • Increase shelf life
  • Improve color and texture
  • Prevent mold from forming
  • Control pH

Because acidulants have so many functions, they’re used in a wide range of foods and supplements.

Look for lactic acid or citric acid on the label — these are acidulants[*].

#8: Colors and Flavorings

Artificial color additives were originally created to help foods appear brighter or more vivid for ads.

Most people assume these are only found in sweet treats like neon-colored Jello and bright pink cake frosting, but they can also be lurking in cheese, margarine and some of your favorite snack foods[*].

Flavor additives, on the other hand, help to offset any bad tastes associated with the supplement and make them more palatable.

If something tastes good, you’re more likely to keep using it. But if your supplements taste terrible, you’ll probably switch brands or never buy them again.

Some of the most common flavor enhancers are sweeteners, which come in both natural forms like fruit extracts and artificial ones like high fructose corn syrup, aspartame and saccharin.

Now that you know the basic categories of additives in supplements, let’s get specific. Keep in mind, these are only the overarching additive categories for supplements.

Like I mentioned earlier, there are currently over 3,000 approved additives manufacturers can include in food items.

Since it would be impractical cover all of them, let’s go over the 11 most harmful ones next.

11 Popular Supplement Fillers to Avoid

The following supplement fillers are the worst offenders to your health and should always be avoided, including:

#1: Magnesium Stearate

You may not know its formal name, but you’ve probably seen magnesium stearate in action.

It’s the white powder layer you’ll often find on vitamins.

This additive falls under the flow agent category since it’s used to keep the manufacturing process moving along smoothly by preventing the capsules from getting stuck to the machines.

It also prevents them from sticking together in the bottle.

In the last 10 decades, the potential risks associated with magnesium stearate consumption haven’t been thoroughly studied.

In one of the studies available, researchers found that magnesium stearate weakened the immune system and destroyed important T-cells associated with immunity in mice[*].

However, humans and mice differ here because mice don’t have the same enzymes people do. So when researchers tried to replicate these findings in humans, they were unsuccessful.

Does that mean magnesium stearate is safe for humans?

In small amounts, it may be.

But consume too much and it may cause weakness and impair neuromuscular transmission[*].

If you’re consuming a supplement with magnesium stearate everyday, you’ll start to accumulate high doses of it in your system, and this may lead to the muscular issues I just mentioned.

So while small doses is loosely defined, you have to consider the big picture and how it will all add up each day and every week.


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The last issue with this additive is that it can be cheaply sourced.

As a synthetic additive, it may come from genetically modified cottonseed or canola, which are extremely harmful for you health.

#2: Sodium Benzoate

Sodium Benzoate is another additive that prolongs the shelf life of your supplement by ensuring it doesn’t have a chance to spoil.

It’s deemed safe by the FDA in small doses, but in practice it’s easy to go over this limit, and the impact on your health can be significant.

Studies show this additive may magnify hyperactivity and ADHD in children[*].

In adults, sodium benzoate can also trigger and increase chances of asthma attacks[*].

And when this additive is combined with ascorbic acid (vitamin C), it becomes the carcinogen (i.e., cancer causing substance) known as benzene[*].

Ingestion of foods and drinks with high levels of benzene can cause stomach irritation, dizziness, sleepiness, and in the worst cases vomiting and convulsions.[*]

The next additive shares this awful characteristic too.

#3: Titanium Dioxide

You’ve probably consumed a product containing titanium dioxide without knowing it.

This time, instead of the white powder residue that comes with magnesium stearate, you get a perfectly white colored tablet with titanium dioxide.

But aside from giving you a bright white capsule, titanium dioxide may create or exacerbate negative gut symptoms.

So far, researchers have learned titanium dioxide may trigger immune reactions of the intestine after oral intake, triggers issues like IBS and Leaky Gut Syndrome, and irritate people already suffering from colitis and Crohn’s disease[*][*].

You can see why this additive is worth avoiding. The same goes for this next one.

#4: Silicon Dioxide

Silicon dioxide is made from two abundant compounds: silicon and oxygen. It’s used in food products to prevent clumps and to absorb moisture to ensure freshness.

Wondering how it does that?

The secret is sand.

Yes, sand.

The same sand that’s between your toes at the beach is also known as silicon dioxide.

One of the reasons why sand is used as a flow agent food additive is because it doesn’t get absorbed by your body[*].

This means your kidneys filter the silicon dioxide right out and it doesn’t interfere with the active ingredients in the supplement.

According to several studies, there’s no clear or strong evidence of silicon dioxide’s toxicity and safety to the human body.

However, an evaluation published in the Journal of Applied Toxicology determined that a higher concentration and longer exposure, silicon dioxide interferes with cell cycle and inhibits cell growth in the gastrointestinal tract.[*]

Researchers concluded that even though silicon dioxide could be used as a safe food additive, more investigations, such as long-term in vivo exposure, are necessary in future studies.

Due to this uncertainty, the European Food Safety Authority (EFSA) doesn’t classify silicon dioxide as safe.[*]

#5: Magnesium Silicate

You may know magnesium silicate in its more common form: talc, or talcum powder.

Talc has recently become a household name in a bad way thanks to emerging research connecting it to increases in[*]:

  • Ovarian cancer
  • Lung cancer
  • Endometrial cancer

Japanese researchers also discovered that when consumed in high amounts, this carcinogenic additive can also lead to high rates of stomach cancer too[*].

And while more research is needed, so far it’s safe to say you should steer clear of this one, and definitely this next one too.

#6: Soybean Oil

Soybean oil is more straightforward than the other lab-created chemicals on the list, but it’s not any better for you.

As the name suggests, it comes from soybeans[*].

One of the biggest problems with soybean oil is that many manufacturers use genetically modified soy, which is heavily exposed to chemical pesticides during production.

Not only that, soybean oil will negatively affect anyone with a peanut or soy allergy, which means it’s off limits if you fall within this category.

And, finally, when it comes to soy products, you may also unknowingly create a hormonal imbalance thanks to its phytoestrogen effects, which is the last thing you want your supplements to do[*].

Soybean oil is best avoided, just like this next one.

#8: Shellac

This additive is what creates the shiny and glossy coating in capsules, but what truly makes it unique is its sourcing.

Do you know where it comes from? A female lac insect excretes it and manufacturers turn it into usable resin[*].

According to research, in large amounts, shellac[*]:

  • Is considered harmful if swallowed
  • Causes skin irritation
  • Causes serious eye irritation

In general, it’s considered an allergen[*].

Shellac isn’t usually mentioned by name in food products. Just like sugar and sweeteners, it goes by several names, including:

  • Natural glaze
  • Pure food glaze
  • Confectioner’s resin

This means you may have been unknowingly eating this allergen for quite some time.


Similar to soybean oil, when you find cornstarch in your supplements,you’re increasing your chances of consuming a GMO ingredient heavily exposed to harmful pesticides thanks to the corn its derived from.

Both of these traits can lead to developing sensitivities and allergies, which is reason enough to ditch them.

#9: Citric Acid

Citric acid also falls under that same umbrella: it’s usually made from GMO corn and heavy pesticide use is common.

Keep in mind, we’re referring to the chemically-made version here.

Ascorbic acid (aka vitamin C) is the natural version found in fruits and veggies, which can help prevent kidney stones[*].

As for the chemical alternative, citric acid can lead to gastrointestinal disturbances such as diarrhea, indigestion, nausea, and heartburn.[*]

The next additive can also wreak havoc on your digestive system.

#10: Carrageenan

Carrageenan is found in numerous seemingly healthy and sometimes organic food products.

You’ll find it in most almond milks on the market and even in sour cream and kefir.

For manufacturing purposes, carrageenan is used to thicken products that may otherwise be too runny.

But once consumed, carrageenan can cause gastrointestinal side effects. One study found that human intestinal cells exposed to carrageenan had an increased cell death, reduced cell proliferation, and cell cycle arrest (stopped participating in cell division)[*].

If you’ve ever had a bad reaction to the MSG commonly found in takeout and junk food, you’re more likely to experience a similar situation with carrageenan.

But even if you’re not sensitive to it, you should still ditch it for your health’s sake, just like our last additive.

#11: Potassium Sorbate

Potassium sorbate is another popular additive used to extend the shelf life of foods and supplements.

By preventing the growth of mold and bacteria, it can make food stay around longer than it should.

Some negative side effects of potassium sorbate include[*]:

  • Migraines
  • Higher potassium levels, or hyperkalemia
  • Allergic reactions such as itching, congestion and abdominal pain (usually within the first two hours of eating it)

Now that you know which supplement fillers to avoid, your head may be spinning with what to do next.

There are better options out there and we’re going to help you find them.

How to Choose Supplements Without Harmful Ingredients

Since supplements are not regulated by the FDA, it’s up to you to do your research and find the best options.

While the ingredients we discussed today are generally considered safe to use by the FDA, you may still have a negative reaction to them because not all of them have been properly researched for safety and toxicity.

Fortunately, there are safer options out there you can trust. Follow these two simple rules when looking for a high-quality supplement:

  • Check the ingredient label. If the list is stacked with some of the ingredients in today’s guide or you don’t recognize them as food, you have two red flags that tell you to put it back on the shelf.
  • Choose products with a short ingredient list. Less is more when it comes to supplements.

The good news is you don’t have to travel too far to find supplements free of questionable additives and cheap fillers. Our line of supplements at Perfect Keto is doctor-formulated and doesn’t contain any fake, cheap, or unnecessary fillers.


Join 90k+ people who are losing weight with Keto Kickstart, our doctor-developed program designed to give you real weight loss results.

No matter which supplements you choose, they should always be free of dubious ingredients that don’t contribute to the nutrition or benefits of the product. Luckily now you can spot the difference.


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