Phthalates have been linked to reproductive and developmental problems, hormonal disruptions, and even certain types of cancer.
Why Are They Being Used in the First Place?Chemists often rely on versatile phthalates to formulate different products, including pharmaceuticals, because phthalates enhance the effectiveness of certain drugs through various mechanisms.
Phthalates have high compatibility with a wide range of ingredients and oils. They can also slow evaporation and give products long-term stability.
Toxic Substances in OTC Drugs and SupplementsA 2012 study that investigated the use of phthalates as ingredients in drugs found that a wide range of prescription and over-the-counter (OTC) products and supplements from different therapeutic categories incorporate various phthalates.
The study found that phthalates are used in these products as "inactive" ingredients. Inactive ingredients in medicine are usually added to improve the efficacy of active agents, mitigate unpleasant tastes, or preserve medications until their expiration date.
However, some medical professionals express concerns that the phthalates contained in these drugs may have adverse effects.
“Exposure to low dosages like in drugs can change gene expression by reprogramming the molecular system in cells, protein level, receptor expression, and DNA methylation,” said Dr. Luíza Mirpuri, a renowned phthalate expert. “All of these are known to influence health adversely.”
Hormone-Disrupting ChemicalsPhthalates are categorized as endocrine-disrupting chemicals, which can interfere with the normal functioning of male and female hormones.
Do Phthalates Cause Breast Cancer?To explore the effects of phthalates on human health, a team of Danish researchers conducted a study to examine whether there was an association between phthalate exposure via pharmaceuticals and higher breast cancer rates.
The study's hypothesis was based on the understanding that phthalates, known for their estrogen-mimicking properties, could influence the occurrence of estrogen receptor-positive breast cancer.
In a comprehensive review involving almost 10 million women, the researchers found that women exposed to high levels of phthalates had a twofold increase in the likelihood of developing breast cancer. The study was published in the Journal of Clinical Oncology in 2019.
FDA Oversight QuestionedWhile the U.S. Food and Drug Administration (FDA) is widely perceived to have stringent oversight in the regulatory process for phthalate-containing drugs, a paper published in Environmental Health Perspectives notes that even though certain phthalates aren't technically approved for general use as inactive ingredients, they're allowed to be included in approved drug products with specific maximum levels.
According to the paper, OTC drugs don't require the same ingredient review as their prescription drug counterparts as long as no new ingredients are included.
And although the FDA may know the ingredients in certain drugs, manufacturers aren't obligated to disclose a complete ingredient list to the public because of patent protection laws. As a result, consumers may not know whether a particular drug contains phthalates.
According to Dr. Mirpuri, there's concern that regulatory agencies, such as the FDA, may not fully grasp the potential health risks associated with phthalates.
“They say that low-dose exposure is harmless," she said. "I find this to be unacceptable as a doctor.”
She drew a comparison between phthalates and DDT, an insecticide that was widely produced in the past but was banned because of its cancer-causing properties. According to her, the similarity lies in the fact that both substances weren't initially recognized as significant pollutants or contaminants. However, both can persist, accumulate, and exhibit toxic effects.
“I believe [phthalates] to be another ‘Silent Spring,’” Dr. Mirpuri said.