Top 7 Ingredients You do Not Want in Your Supplements

In today’s world, nutritional supplements have become a staple in our daily health routines. However, the journey towards wellness can be confusing due to the overwhelming number of products available, each claiming to offer the elixir of life. As a clinical nutritionist and functional medicine practitioner, I have discovered a concerning reality while navigating the landscape of dietary supplements. Many supplements, which are often recommended by conventional doctors lacking specialized training in nutrigenomics and targeted supplementation strategies, contain harmful additives and ingredients that could potentially cause more harm than good.

Variety of dietary supplements in capsules and tablets, emphasizing the need for careful ingredient selection

The Hidden Dangers Hiding in Your Supplements

The use of supplements has increased significantly due to recommendations from healthcare professionals who may not have expertise in nutritional science. While well-intentioned, this guidance may lead patients to consume products that contain harmful substances.

Hazardous Additives and Ingredients

Artificial Colors and Sweeteners

Artificial colors, such as FD&C Red No. 40 (E129 in Europe), and artificial sweeteners like aspartame (E951), are prevalent across the supplement industry. Despite FDA approval and corresponding European designations [1], there’s growing research and public concern about their safety. For instance, E129 has been investigated for its potential link to behavioral issues in children [2]. Similarly, E951, once hailed as a healthier sugar alternative, has been associated with increased risks of metabolic syndrome and diabetes [3].

How they might appear on labels:

  • FD&C Blue No. 1: Also listed as Brilliant Blue FCF, E133
  • FD&C Red No. 40: Also known as Allura Red AC, E129
  • FD&C Yellow No. 6: Sunset Yellow FCF, E110
  • Titanium Dioxide: E171
  • Aspartame: E951, sometimes simply listed as Aspartame, or under brand names like NutraSweet, Equal
  • Sucralose: E955, marketed under the brand name Splenda
  • Saccharin: E954, may be listed simply as Saccharin; also known as Sweet’N Low, Necta Sweet
Close-up of a supplement ingredient label listing harmful additives like artificial colors and sweeteners

Hydrogenated Oils

Known as trans fats, hydrogenated oils are a major health concern, linked to increased bad LDL cholesterol and decreased good HDL cholesterol, heightening the risk of coronary heart disease (CHD) [4]. Yet, they find their way into supplements as cheap fillers, misleading consumers about the health benefits.

How they might appear on labels:

  • Partially Hydrogenated Oil: Often followed by the source, such as “Partially Hydrogenated Soybean Oil”
  • Hydrogenated Vegetable Oil: Can specify the vegetable source, like palm, soybean, or coconut

Contaminants: Heavy Metals and PCBs

Mercury, polychlorinated biphenyls (PCBs), and other contaminants have been found in fish oil supplements. Accumulation of these substances in the body can pose serious neurological and cardiovascular risks [5,6,7,8]. A notable lawsuit in California highlighted the absence of warning labels on fish oil supplements about their cancer risk from high PCB levels[8].

These might not be listed on the label directly but be wary of products sourced from polluted areas or lower-quality fish oils, which are more likely to contain:

  • “Molecularly Distilled Fish Oil” (this is a positive indication that it’s been purified, whereas the absence of this or similar phrases might raise concerns)

Talc (Magnesium Silicate) and Titanium Dioxide

Magnesium silicate, used as a filler and anti-caking agent, has raised safety concerns, especially regarding potential asbestos contamination, a known carcinogen [10,11]. Titanium dioxide, used for coloring supplements white, has faced scrutiny for its links to inflammation and potential carcinogenic effects, with recent evaluations questioning its safety [12,13,14,15,16].

How they might appear on labels:

  • Magnesium Silicate: Can be listed simply as Talc or Magnesium Silicate
  • Titanium Dioxide: May be listed directly as Titanium Dioxide; sometimes referred to for its use as a colorant
Talc powder displayed as a common filler in supplements, associated with health risks

Steering Clear of Harmful Supplements

The Art of Deciphering Labels

Avoiding these hazardous ingredients begins with mastering label literacy. Look beyond the nutritional facts to the “Ingredients” list, where the full spectrum of contents, including harmful additives, must be disclosed.

Selecting Safe Supplements

  • Prioritize supplements derived from whole foods, as these are less likely to contain synthetic additives.
  • Seek out products with trusted certifications (organic, non-GMO, third-party tested) that signify a commitment to purity and safety.
  • Familiarize yourself with optimal nutrient forms for better absorption and health benefits, choosing supplements that adhere to these standards.
  • Here are the supplements I choose for my clients: functional nutrition supplements

Advocacy for Better Health Choices

We wield power as consumers to influence the supplement market by supporting brands dedicated to health and transparency. Further, by spreading awareness about the hidden dangers in some supplements, we can collectively make more informed decisions.

Concluding Thoughts

Our health journey is shaped by the choices we make, from our diet to the supplements we incorporate into our routines. By exercising discernment and demanding higher standards from the supplement industry, we safeguard our health and the environment.

Consult with a healthcare professional, ideally one with expertise in nutritional science, before beginning any new supplement to ensure it complements your health needs without exposing you to unnecessary risks.

In the quest for wellbeing, let knowledge be your guiding light. Stay informed, remain skeptical of unchecked recommendations, and always aim for the healthiest version of yourself.


  1. Official Journal of the European Union. Regulation (EC) No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:354:0016:0033:en:PDF. Accessed 2008.
  2. Fulton A. FDA probes link between food dyes, kids’ behavior. NPR. http://www.npr.org/2011/03/30/134962888/fda-probes-link-between-food-dyes-kids-behavior. Published 2011.
  3. U.S. Food and Drug Association. Overview of Food Ingredients, Additives, and Colors: Types of Food Ingredients. http://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm094211.htm#types. Accessed March 2013.
  4. Center for Disease Control and Prevention. Trans Fat. http://www.cdc.gov/nutrition/everyone/basics/fat/transfat.html. Accessed 2010.
  5. MedlinePlus. Fish Oil. http://www.nlm.nih.gov/medlineplus/druginfo/natural/993.html. Accessed 2014.
  6. American Heart Association. Fish and Omega-3 Fatty Acid. http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyDietGoals/Fish-and-Omega-3-Fatty-Acids_UCM_303248_Article.jsp. Published May 14, 2014.
  7. Salzberg S. Those fish oil supplements might cause cancer. Forbes.com. http://www.forbes.com/sites/stevensalzberg/2013/07/23/those-fish-oil-supplements-might-cause-cancer/. Published July 23, 2013.
  8. Finney M. Lawsuit over contamination in fish oil supplements. ABC7news.com. http://abclocal.go.com/kgo/story?id=7306625. Published March 2, 2010.
  9. Warner J. Consumer reports: some popular fish oil supplements may contain PCBs. WebMd.com. http://www.webmd.com/diet/news/20111206/some-fish-oil-supplements-fishy-on-quality. Published December 7, 2011.
  10. Merliss RR. Talc-treated rice and Japanese stomach cancer. Science. 1971;173(4002):1141-1142. doi:10.1126/science.173.4002.1141.
  11. U.S. Food and Drug Administration. Select committee on GRAS Substances (SCOGS) Opinion: Magnesium silicate. http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/SCOGS/ucm260465.htm. Published April 18, 2013.
  12. Choi G-S, et al. Titanium dioxide exposure induces acute eosinophilic lung inflammation in rabbits. Industrial Health. https://www.jstage.jst.go.jp/article/indhealth/advpub/0/advpub_2013-0105/_article. Published March 7, 2014.
  13. Chang X, Fu Y, Zhang Y, Tang M, Wang B. Effects of Th1 and Th2 cells balance in pulmonary injury induced by nano titanium dioxide. Environ Toxicol Pharmacol. 2014;37(1):275-83. doi: 10.1016/j.etap.2013.12.001.
  14. Makumire S, Chakravadhanula VS, Kollisch G, Redel E, Shonhai A. Immunomodulatory activity of zinc peroxide (ZnO2) and titanium dioxide (TiO2) nanoparticles and their effects on DNA and protein integrity. Toxicol Lett. 2014;227(1):56-64. doi: 10.1016/j.toxlet.2014.02.027.
  15. Gui S, Sang X, Zheng L, et al. Intragastric exposure to titanium dioxide nanoparticles induced nephrotoxicity in mice, assessed by physiological and gene expression modifications. Particle and Fibre Toxicology. 2013;10:4. doi:10.1186/1743-8977-10-4.
  16. Nogueira CM, Mendes de Azevedo W, Dagli MLZ, et al. Titanium dioxide induced inflammation in the small intestine. World J Gastroenterol. 2012;18(34):4729–4735. doi: 10.3748/wjg.v18.i34.4729.

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