Risk alert: phthalates are hiding in supplements too!

bottles of generic supplements

By Dr. Mary James, ND

You’ve switched shampoos and sunblock to avoid the risks of endocrine disruptors. But have you ever wondered whether harmful phthalates — one of those endocrine disruptors that can interfere with hormonal activity in your body — might be hiding in your supplements too?

Several types of phthalates were banned in the U.S. back in 2008. But when a group of researchers from Harvard and Boston University examined some of the inactive ingredients in medications and supplements, their findings were disturbing. Of the hundreds of individual products they examined, phthalates were often disclosed in coatings or capsule materials — and many more did not specify what inactive ingredients were used.

I think it’s time we all take a closer look at what could be hiding in our favorite products.

Are your supplements coated in endocrine-disrupting toxins?

Unfortunately, there is no law requiring manufacturers to list the specific inactive ingredients — such as the phthalates used in coatings or capsules — in the nutrition facts panel. Most don’t tell you.

But at Women’s Health Network, we want you to know. We don’t use enteric coatings or phthalate-containing capsules for our supplements, including Omega-3s, Magnesium Citrate and our Super Biotic probiotic, to help you avoid adding to your phthalate burden.

Further, we have done an extensive review of “certificates of analysis” for our products, and confirmed that none of our products contains phthalates. And we do certificates of analysis on every single batch of every product we make.

For other supplement brands, you’ll need to look at the bottle and see if ingredients such as diethyl phthalate (DEP), di-n-butyl phthalate (DBP), or phthalate polymers such as hypromellose phthalate (HMP), cellulose acetate phthalate (CAP) or polyvinyl acetate phthalate (PVAP) are used.

Check the labels, though not seeing phthalates listed is unfortunately no guarantee that they’re not present — especially in capsules or products with enteric coatings or labeled “delayed release,” like some — not all — digestive enzymes and probiotics. There is no real way to determine whether the “inactive ingredients” in pill coatings or capsules include phthalates unless you take the somewhat extreme step of calling the manufacturer and asking. A company that prides itself on quality and purity will usually be willing to answer such questions.

The dangers of phthalates in certain supplements

There’s growing evidence that phthalates may cause disruptions in thyroid and reproductive hormones. That means if you’re taking a contaminated supplement to help with a particular hormonal imbalance, the chemicals hitching a ride on that supplement could actually be making your imbalance even worse.

And there’s also evidence that phthalates suppress levels of vitamin D in your blood, which can negate many of the health benefits of vitamin D.

Simply put, endocrine disruptors like phthalates are toxins that don’t belong in your body and can cause health problems. Yet the Centers for Disease Control and Prevention noted in studies undertaken 15 years ago that metabolites of as many as 13 different phthalates were present in individuals 6 years old and older. Some of these might have come from plastic toys, since phthalates are often used to make plastic more pliable.

Phthalates are one of the most common types of endocrine-disruptors and contribute to a wide range of serious health issues, including:

  • Diabetes
  • Metabolic syndrome
  • Cardiovascular diseases
  • Cancer
  • Obesity
  • Infertility

That’s quite a list of possible risks from these chemicals — and it’s far from complete!

How to avoid endocrine disruptors

Even those of us who strive to “eat clean” and look carefully at where our food and beverages are sourced from can’t possibly cast a critical eye on everything.

And while there’s really no way to avoid phthalates completely — you can dramatically reduce your daily exposure with these simple steps:

  • Avoid buying bottled water. Carry a metal or glass water bottle with you, and use a water filter to reduce the chemicals in your tap water before filling your bottle.
  • Store food in glass or metal containers rather than plastic. Also avoid buying food products that come in plastic bottles or containers whenever possible.
  • Limit your cosmetics, soaps and personal care items. Choose only brands that clearly commit to avoiding the use of phthalates and other endocrine disruptors in their formulations.
  • Choose fresh, rather than canned, fruits and vegetables. If you cannot get fresh options, use frozen rather than canned. As a general rule, avoid processed foods.
  • Keep your meat intake low (and lean). Humans aren’t the only creatures exposed to phthalates — they’re also present in the fat of animals used for food.

And of course, choose your supplements with care!

  • Binder AM, Corvalan C, Calafat AM, Ye X, Mericq V, Pereira A, Michels KB. Childhood and adolescent phenol and phthalate exposure and the age of menarche in Latina girls. Environ Health. 2018 Apr 3;17(1):32.
  • Johns LE, Ferguson KK, Meeker JD. Relationships Between Urinary Phthalate Metabolite and Bisphenol A Concentrations and Vitamin D Levels in U.S. Adults: National Health and Nutrition Examination Survey (NHANES), 2005-2010. J Clin Endocrinol Metab. 2016 Nov;101(11):4062-4069. Epub 2016 Sep 20.
  • Kasper-Sonnenberg M, Wittsiepe J, Wald K, Koch HM, Wilhelm M. Pre-pubertal exposure with phthalates and bisphenol A and pubertal development. PLoS One. 2017 Nov 20;12(11):e0187922. doi: 10.1371/journal.pone.0187922. eCollection 2017.
  • Kelley KE, Hernández-Diaz S, Chaplin EL, et al. Identification of Phthalates in Medications and Dietary Supplement Formulations in the United States and Canada. Environ Health Perspect. 2012 Mar; 120(3): 379–384.
  • Petrakis D, Vassilopoulou L, Mamoulakis C, et al. Endocrine Disruptors Leading to Obesity and Related Diseases. Int J Environ Res Public Health. 2017 Oct; 14(10): 1282.
  • Przybyla J, Geldhof GJ, Smit E, Kile ML. A cross sectional study of urinary phthalates, phenols and perchlorate on thyroid hormones in US adults using structural equation models (NHANES 2007-2008). Environ Res. 2018 May;163:26-35. doi: 10.1016/j.envres.2018.01.039. Epub 2018 Feb 6.
  • Serrano SE, Braun J, Trasande L, et al. Phthalates and diet: a review of the food monitoring and epidemiology data. Environ Health. 2014 Jun 2;13(1):43.


For more details on how to avoid endocrine disruptors, along with a list of the most-common toxins, see our article Endocrine disruptors – the hormonal effects of everyday