Taking supplemental nutrients are standard practice these days. People are taking supplements to address missing nutrients from their diet, or as tools to optimise their health and wellbeing.

There are so many different supplements available it can feel like a maze trying to navigate all the different options — it’s difficult to know which supplements are good, and which ones aren’t so good.

One of the biggest sources of this confusion is additives contained in these nutritional supplements. Some have natural additives, others use synthetic additives.

Which one is better? Does this even matter?

Let’s get into it and discuss why supplement companies use additives, and why we recommend going for the natural additive options and avoid synthetic versions.


Why Do Supplements Have Additives in the First Place?

The vast majority of nutritional supplements and pharmaceutical medications require at least some additives.

They serve all kinds of purposes, from bulking the product up to a more convenient size, to preventing the machines from clogging up during the manufacturing process. It really depends on the active ingredients within the supplement, and how they behave during the manufacturing process that determines what additives are included.

Common Supplement Additives Include:

  • Fillers

Fillers are used to give supplements more bulk. They’re especially useful when the active ingredient in the supplement requires only a very small dose.

  • Binding Agents

These are especially important in tablets. Without a binding agent, the tablets would soon dissolve and fall apart in the bottle, leaving you with a bottle of dust by the time you get it home.

  • Preservatives

Preservatives are self-explanatory, they keep the supplement from going bad with mold or bacterial growth — which can be extremely harmful to your health.

  • Colouring Agents

Colouring agents aren’t always necessary, but they’re useful for giving the supplement an attractive colour. This may seem like a small touch, but a lot of supplements actually come out with a dirty-brown colour, making them very unattractive in appearance.

  • Flavouring Agents

Certain supplements, such as fish oils, have a terrible taste. Adding a flavouring agent to the supplement makes the supplement much easier to take. These are especially common in supplements or vitamins that come as a tablet rather than a capsule because the contents are more likely to activate the taste receptors on the tongue.

Natural vs. Synthetic Additives

So how do natural and synthetic additives compare to each other?

There are positives and negatives to each option, depending on what you’re using the supplement for and what your budget is.

Comparing natural and synthetic additives:


Pros Cons
Natural Additives
  • Generally regarded as the safer option
  • They don’t always work as well as synthetic options
  • Can be expensive
Synthetic Additives
  • Cheaper than natural options
  • Stores for longer periods of time
  • May produce negative side-effects



Testing the Safety of Additives:

In the European Union, food additives are regulated by the FSA. If the additives pass the safety tests, the compound is given an E number and allowed for use in supplements. Both natural and synthetic additives need to go through this process before they’re allowed for human consumption.


What Makes an Additive Natural?

The word natural can be a bit tricky. There aren’t any real regulations that control how the word is used, so we often find compounds that are hard to consider as natural the way we think it should mean.

A lot of vitamin C supplements, for example, are manufactured in a lab — yet come with the words natural written down the side of the bottle. The idea is that vitamin C is found naturally, even if this particular batch is made in a lab.


The public perception of natural means that the ingredients have to have come from a completely natural source — usually a plant.

Additives are often made from natural ingredients. Things like brown rice flour, magnesium, colouring agents made from fruits and berries, thickening agents made from guar gum or agar, and preservatives from essential oils of plants can all be used to give the supplement the desired qualities.


Are Synthetic Additives Dangerous?

Some synthetic additives are dangerous, others aren’t — it really comes down to each ingredient individually.

Over the last couple of years, there’s been a lot of research highlighting the potential dangers of synthetic additives that we previously thought were safe.

It seems times are changing, and even small amounts of some additives have been shown cause serious health problems long-term.

Common synthetic food colourings, for example, have been linked with hyperactivity and attention deficits in children [1].


Some Other Examples of Negative Side-Effects of Synthetic Additives:

  • Nausea/vomiting
  • Cancer
  • Allergic reactions
  • Inflammation in the digestive tract
  • Poor absorption
  • Headaches
  • Problems during pregnancy
  • Increased risk of heart disease
  • Weight gain
  • Cognitive deficits

Examples of Natural vs. Synthetic Additives:

Natural Options Synthetic Options
  • Cellulose
  • Gelatin
  • Stearic acid
  • Brown rice flour
  • Magnesium chelates
  • High fructose corn syrup
Binding Agents
  • Carob gun
  • Guar gum
  • Agar
  • Xanthan gum
  • Hydroxypropyl cellulose (HPC)
  • Polyvinylpyrrolidone (PVP)
  • Polyethylene glycol (PEG)
  • Essential oils
  • Sulfur dioxide
  • Sodium sulfite
  • Sodium nitrate
  • Butylated hydroxyanisole (BHA)
  • Sulfur dioxide
Colouring Agents
  • Beet extracts
  • Berry extracts
  • Mushroom extracts
  • Saffron
  • Blue #1 and Blue #2
  • Red dye # 3
  • Yellow #6
Flavoring Agents
  • Stevia extracts
  • Piperine
  • Essential oils
  • Fruit extract
  • Aspartame
  • MSG (monosodium glutamate)
  • High fructose corn syrup

Should I Avoid Supplements Containing Synthetic Additives?

Most supplements use additives to make them more effective, or easier to take. Additives, in general, aren’t a bad thing at all. Companies that add these compounds to their supplements have a good reason for doing so — they may be trying to prevent their products from going off on the shelf, adding flavouring agents to improve the taste, or using binding agents to keep tablets nice and uniform.

None of the additives on the market currently are considered toxic in the doses they’re used in — according to the FSA and other regulators at least.

However, a growing body of evidence is suggesting synthetic additives like food dyes, magnesium silicate, BHT, and MSG may have a negative impact on health with long-term use.

Generally speaking, natural additives are the better option, even if they tend to cost a little bit more on average than synthetic options.



  1. Stevens, L. J., Kuczek, T., Burgess, J. R., Hurt, E., & Arnold, L. E. (2011). Dietary sensitivities and ADHD symptoms: thirty-five years of research. Clinical pediatrics, 50(4), 279-293.
  2. Joint FAO/WHO Expert Committee on Food Additives. Meeting, & World Health Organization. (2006). Safety evaluation of certain food additives (No. 56). World Health Organization.
  3. World Health Organization. (2016). Safety evaluation of certain food additives and contaminants, supplement 1: non-dioxin-like polychlorinated biphenyls.