The use of parabens became quite controversial after being found in the cells of breast cancers patients. Early research showed parabens affect hormone function.
This can cause changes in cholesterol, blood sugar, thyroid, and immune function. The risk of allergies, obesity, and infertility has also been associated with the use of parabens.
Read on to learn more about the different types of parabens, their potential to affect your health, and where you can find them. Keep in mind that paraben research has been limited to animal and cell studies. Further research is needed on the effects of parabens on humans to confirm the long-term effects of use.
Negative Health Effects of Parabens
The US Food and Drug Administration (FDA) and the Cosmetic Ingredient Review (CIR) tests ingredients in food and cosmetics for safety. Neither organization found any risks with the use of parabens.
The FDA said the use of up to 0.1% of methyl- and propylparabens was safe for food and drinks. Cosmetics usually contain between 0.01% and 0.3% parabens. According to the CIR, these compounds are safe in doses of up to 25%.
Other research says parabens are endocrine-disrupting chemicals (EDCs) that cause problems to the endocrine system. EDCs attach to cells in the body, which results in blocking or weakening hormone cell communication.
Changes in Hormone Function
Parabens cause changes in hormone function, which can result in the following:
Changes in brain functionChanges in cholesterolHigh blood sugar Changes in thyroid hormonesPoor immune functionSensitivities, allergies, and rashesFertility issuesObesity riskRisk of cancer
Changes in Brain Function
Some parabens may harm the brain. Others may help it.
One study found that butyl- and isobutyl-parabens prevented learning in animals. The same animals also experienced low levels of antioxidants, more inflammation, and anxiety.
However, propylparaben was found to reduce the effects of traumatic brain injury associated with Alzheimer’s disease.
Changes in Cholesterol
Cholesterol is needed to make estrogen and testosterone. Parabens can stop these essential hormones from being made.
A connection between triglycerides and the levels of methyl-, ethyl-, and propylparabens was also seen in humans. Triglyceride levels varied by age, sex, weight, and ethnicity.
Those with high triglycerides were older, obese, and/or male. Women, non-Hispanic Whites, and non-Hispanic Blacks with paraben exposure had lower triglyceride levels. Canadian men exposed to propylparaben also had a risk of developing high cholesterol. Women exposed to methyl-, propyl-, and ethylparaben had increased levels of good cholesterol, HDL.
High Blood Sugar
A mixture of parabens seems to do more harm than one paraben alone. A combination of butyl- and propylparabens increased the blood sugar for pregnant women in their first and second trimesters. This puts them at risk for gestational diabetes.
Less is known about the effects of parabens in non-pregnant individuals. One study found no significant changes in those exposed to parabens.
Similar effects could occur in men and non-pregnant women. More research is needed to understand how parabens affect blood sugar overall.
Poor Immune Function
Good immune function is tied to a healthy gut. Using antimicrobial parabens prevents the growth of healthy bacteria. This can weaken the immune system.
Parabens cause the production of Type 2 helper T (Th2) cells. Th2 cells make the immune system very sensitive., causing it to overreact to stimuli more than normal. Th2 cells are also found in those with asthma and eczema.
Parabens can weaken immune defenses. The presence of methylparabens was associated with fewer Th1 cells, which prevent autoimmune responses. This will protect the body from attacking its own cells.
Sensitivities, Allergies, and Skin Rashes
The skin has its own microbiome. Parabens can reduce the number of healthy bacteria on the skin, weakening the skin’s immune system.
Allergies and sensitivities can develop, and some people may experience a histamine response. Symptoms include red, itchy, and dry skin. Skin rashes can occur anywhere on the body, including the scalp. Scalp rashes will dry out the hair and may even cause hair loss.
Methylparaben is a small paraben that is unlikely to cause allergies and sensitivities. Butylparaben is a medium-sized molecule that is bigger than methylparabe, but smaller than large parabens. It also has a weaker response than large molecules like heptylparaben.
Medications with parabens placed on broken or damaged skin may also cause skin reactions. Parabens in food can also cause reactions but are rare.
Other Risks
Other identified risks of paraben exposure include:
Risk of cancer: Parabens can activate the hormone estrogen. High levels of estrogen have been found in breast cancer tumors. Breast cancer is also associated with the continual use of paraben-containing personal care products applied near the breast area. Fertility issues: Parabens can lower testosterone and sperm production. However, research is limited to animals and failed to prove toxicity in females with paraben-related uterine growths. Changes in thyroid hormones: Females with high levels of butylparaben experienced lower levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). These changes could cause thyroid dysfunction. Obesity risk: Methyl- and propylparabens were found in women with higher BMIs. Food and dietary supplements with high levels of parabens may be responsible for weight gain.
Who Is at Risk for Paraben Exposure?
Parabens are absorbed when we eat foods and drinks containing these substances. The skin also takes in paraben when products with these chemicals are applied to the face and body. Parabens have also been found in the sediment, sewage, water treatment plants, rivers, soil, and house dust.
Parabens are all around us so everyone may have some exposure. Especially if you consume foods and drinks and/or use certain paraben-containing products.
Higher Levels of Parabens Have Been Found in Certain Individuals
The National Health and Nutrition Examination (NHANES) survey found about 33% of the 9,813 individuals tested had a presence of parabens at or above the limit of detection in their urine.
Types of Parabens
Parabens are made from para-hydroxybenzoic acid (PHBA). PHBA is an acid found in bacteria, plants, and fruits.
Urinary levels of parabens were higher in women than men. People 20 years and older had higher paraben levels than younger survey participants. Asians had the highest levels of butyl- and ethyl- parabens. Non-Hispanic Blacks and Mexican Americans had the highest levels of methylparabens. Non-Hispanic blacks had the highest levels of n-propyl parabens.
Parabens are made from an acid-base chemical reaction called esterification. When PHBA and alcohol are combined they create an ester. Esters vary by the number of chemical bonds in the molecule. The type of alcohol used will determine the number of esters.
Methylparaben (methanol)Ethylparaben (ethanol)Isopropylparaben (isopropanol)Propylparaben (n-propanol)Butylparaben (butanol) Isobutylparaben (isobutanol)Pentylparaben (pentanol)Heptylparaben (heptanol)Benzylparaben (benzyl alcohol)Pentylparaben (pentyl alcohol)
The more ester bonds the more active the paraben. So medium, long, and/or branched-chain esters are more harmful.
Methyl- and ethylparabens are short-chain parabens. They have weaker estrogenic effects than medium-chain esters like propylparaben. Long-chain esters like butylparaben are stronger than medium-chain esters. The order of increasing estrogenic activity is as follows:
MethylEthylProplyButylIsobutyl
Long-chain esters are the most harmful according to test-tube studies.
Another thing that determines a paraben’s harm is if it dissolves in fat. Cell studies found parabens like benzylparaben easily bound to estrogen. This is a hydrophobic, long-chain ester.
More research needs to be done to know if these effects can be replicated in humans.
Products With Parabens
Parabens are often found in cosmetics, personal care products (PCP), pharmaceuticals, medicines, and foods. Here is a list of parabens broken out by category.
The type of paraben is determined by the alcohol used in the chemical reaction. It will also tell whether the paraben has short, long, and/or branched-chain ester bonds.
Parabens that dissolve in fat are called hydrophobic parabens. Parabens that are hydrophobic with long and/or branched chains easily bond with estrogen cell receptors. This could be harmful to health.
Cosmetics and Personal Care Products
The main source of paraben exposure comes from cosmetics and personal care products.
Face, body, and hand creams Eye shadow Foundation Blush Eyeliner Mascara Lip gloss, lipstick, lip balm Lotions/Moisturizers Mud packs Skin lighteners Body wash/scrubs Shampoo/Conditioner Shower gel Shaving gel Haircare products Perfume Skin toner Deodorant Nail polish Sunscreen Facial cleanser or soap Makeup remover wipes Baby products
Personal care products often contain methyl-, ethyl-, butyl-, and propylparaben.
Medications and Pharmaceuticals
The concentration of parabens in medications and pharmaceuticals is around 1%. See below for what products fall into this category:
Pills Suppositories Pain relievers Eyewashes Acne medication Medical weight gainers Injectable drugs Condoms and other contraceptives
Foods
Regardless of the type of food packaging (paper, glass, plastic, or can), methyl-, ethyl-, and propylparbens have been seen in 90% of foods. Butyl- and benzylparabens were also found but less frequently. Here is a list of foods that contain parabens:
Beverages
Bottled waterCarbonated soft drinksAlcoholic beverages (beer, wine, bourbon)JuiceMilkInfant formulaCoffee
Dairy Products
YogurtCheeseIce cream
Fats and Oils
Vegetable oilSalad oilOlive oil
Fish and shellfish
Freshwater fishMarine fishShrimpCrabClam
Grains
Wheat flourBreadRiceNoodlesPie/pastriesPastaPizzaCorn productsCookiesCakesCereals
Meats
BeefPorkChickenTurkeyHamSausage
Fruits
ApplesPearsPineapplesPeachesGrapes/raisinsOranges BananasYellow melonsPassion fruitMixed fruits
Vegetables
BroccoliCabbageCarrotsCeleryCucumbersMushroomsOnionPotatoesTomatoesGreen peppersRadishesPumpkinLettuceBeans Mixed vegetables
Animal feeds can also contribute to the level of parabens in meats and other animal products.
Other Foods that Contain Parabens
Jams/jelliesPicklesSaucesDessertsFlavoring syrupsProcessed foods (fish, meat, fruits, and vegetables)CondimentsBean productsOlivesVanilla extractIcings
Summary
Methyl-, ethyl-, butyl-, and propylparaben are the types of parabens in shampoo, food, and other personal care products.
These parabens do not bind to cell receptors as strong as the actual hormone estrogen. Research shows they are fine in low doses. However, intake may exceed safe levels when numerous paraben-containing products are used on a daily basis.
While the research is limited to animal and cell studies, there’s the potential that parabens can cause health problems. Until controlled human studies are carried out it is hard to know the true effects of long-term paraben use.
In the meantime, you can limit your exposure to parabens cutting back on the use of paraben-containing products.
A Word From Verywell
Animal and cell research shows parabens can act like estrogen which may cause health problems. Unfortunately, there is still a lot we do not know about how these chemicals affect humans. If you have a reaction and think it may be from paraben exposure, be sure to contact your healthcare provider. They can help you get tested to see if you have a paraben sensitivity or allergy.
FormaldehydeQuarternium-15Im-idazolidinyl ureaDiazolidinyl ureaDimethyloldimethyl hydantoinThymolCinnamaldehydeAllyl isothiocyanateCitric acidAscorbic acidRosemary extractFormic acidPropionic acidSorbic acidBenzoic acidSalicylic acidBenzyl alcohol2-phenoxyethanolSodium benzoateTriclosanBronpolDMDM hydantoinMethylisothiazolinoneMethylchloroisothiazolinoneEssential oils (grape seed extract)
These natural preservatives may also cause problems. They have been associated with allergies and other health issues. Formaldehyde has even been linked to cancer. Some may also interfere with medications so be sure to ask your doctor before using any of these products.
Overall there is not enough research to prove any of these are actually safe and effective alternatives to parabens.
Treatment plants work to eliminate parabens from wastewater but only 80% of methyl-, ethyl-, propyl-, and butylparaben are removed.
Parabens pose problems for wildlife. Plankton, algae, dolphins, and polar bears were found to have high levels of these chemicals. The mixture of methyl-, ethyl-, propyl-, and/or butylparaben is more toxic than one paraben alone.
Sulfates, sodium laurel, or laureth sulfate (SLS) is another chemical that causes dry skin. This substance is likely to cause scalp problems similar to parabens. So if you want to prevent potential scalp damage be sure to get a shampoo without parabens and sulfates.
