User login
Parabens were named nonallergen of the year! It is time that we help consumers understand that the substitutes for parabens are often worse than parabens, and parabens are not as sensitizing as we thought. Preservatives are essential parts of most cosmetics and cosmeceuticals. (I say “most” because many organic products do not have them and consequently have shorter shelf lives.) Without them, products are vulnerable to rapid decomposition and infiltration by bacteria, fungi, and molds. The preservatives that are used in the place of parabens often are sensitizers. What do we tell our patients about the safety of parabens with all of these conflicting reports? This column will focus on current thoughts regarding the safety of parabens used as preservatives. I would love to hear your thoughts.
Background
Parabens are alkyl esters of p-hydroxybenzoic acid and have been used as a class of preservatives since the late 1920s and early 1930s. Parabens are found naturally in raspberries, blackberries, carrots, and cucumbers and are common ingredients in food and pharmaceuticals. They are still widely used in skin, hair, and body care products, despite the public outcry against them.1-4
There are many kinds of parabens such as butylparaben, isobutylparaben, ethylparaben, methylparaben, propylparaben, isopropylparaben, and benzylparaben, each with its own characteristics.5 Parabens are considered ideal preservative ingredients because they exhibit a broad spectrum of antimicrobial activity, stability over a large pH and temperature range, have no odor, do not change color, and are water soluble enough to yield an effective concentration in a hydrophilic formulation.3 As the alkyl chain length of parabens increases, they become less water soluble and more oil soluble. Parabens penetrate the skin barrier in inverse relation to its ester chain length.6 Often, several parabens will be combined to take advantage of each paraben’s solubility characteristics.
Many patients avoid parabens because of “health risks.” Now other preservatives are being substituted for parabens, even though these ingredients may be less studied or even less safe than parabens. It is important not to lump all parabens together as they each have different characteristics. Methylparaben and propylparaben are the most commonly used parabens in skin care products.7 Combinations of parabens are notably more effective than the use of single parabens.3,8 High concentrations of any type of paraben can cause an irritant reaction on the skin, but those with longer ester chain lengths are more likely to cause irritation.
Methylparaben
The methyl ester of p-hydroxybenzoic acid is found in many skin care products. It is readily absorbed through the skin and gastrointestinal tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body. Studies have shown it is nontoxic, nonirritating, and nonsensitizing. It is not teratogenic, embryotoxic, or carcinogenic. Methylparaben, because of its shorter side chain groups and greater lipophilicity, has been shown to be more readily absorbed by the skin than other paraben chemicals.8,9 It is also on the low order of ingredients provoking acute and chronic toxicity.3
Propylparaben
Propylparaben is the ester form of p-hydroxybenzoic acid that has been esterified with n-propanol. It is the most commonly used antimicrobial preservative in foods, cosmetics, and drugs. It is readily absorbed through the skin and GI tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body.
Estrogenic activity of parabens
In a 2004 study, Darbre et al. reported on the discovery of parabens-like substances in breast tissue and published these findings in the Journal of Applied Toxicology.10 The media and public panicked, saying that parabens have estrogenic activity and can cause breast cancer. However, many studies have shown that certain parabens do not have estrogenic activity. Although some parabens have been shown to impart estrogenic effects in vitro, these are very weak. The four most commonly used parabens in cosmetic products are 10,000-fold or less potent than 17beta-estradiol.11 The potential to result in an adverse effect mediated via an estrogen mode of action has not been established in humans.6 Paraben exposure differs geographically. No correlation has been found between the amount of parabens in a geographic location and the incidence of breast cancer. Current scientific knowledge is insufficient to demonstrate a clear cancer risk caused by the topical application of cosmetics that contain parabens on normal intact skin.11
Parabens and contact dermatitis
Paraben compounds are capable of minimal penetrance through intact skin.12 When they are able to penetrate the skin – a capacity that varies among the class – parabens are rapidly metabolized to p-hydroxybenzoic acid and promptly excreted in the urine.3,11 Parabens for many years were thought to cause contact dermatitis, and there are many reports of this. However, the incidence is much lower than previously thought. In fact, parabens were named “Nonallergen of the Year in 2018” because of the low incidence of reactions in patch tests.13 Higher concentrations of parabens applied topically to skin – especially “nonintact” skin – have been shown to cause mild irritant reactions. It is likely that many of these reported cases of “contact dermatitis” were actually irritant dermatitis. Longstanding concerns about the allergenicity of parabens in relation to the skin have been rendered insignificant, as the wealth of evidence reveals little to no support for the cutaneous toxicity of these substances.11 Yim et al. add that parabens remain far less sensitizing than agents newly introduced for use in personal care products.4
Daily average exposure to parabens
It is estimated that parabens are found in 10% of personal care products. In most cases, these products contain 1% or less of parabens. If the average patient uses 50 g of personal care products a day, then the average daily exposure to parabens topically is 0.05 g. Parabens also are found in food and drugs, so the total paraben exposure per day is assumed to be about 1 mg/day. (See the 2002 Food and Chemical Toxicology article for details of how this was calculated.)7 When food, personal care products, and drug exposure rates are added, the average person is exposed to 1.29 mg/kg per day or 77.5 mg/day for a 60-kg individual. You can see that personal care products account for a fraction of exposure, as most paraben exposure comes from food.
Government opinion on the safety of parabens for the skin
Parabens long have been assessed as safe for use in cosmetic products in many countries. The European Commission stipulated a maximum concentration of 0.4% for each paraben and 0.8% for total mixture of paraben esters.4,6 While the Federal Food, Drug, and Cosmetic Act of 1938 prohibits the Food and Drug Administration from ruling on cosmetic ingredients, the industry-sponsored Cosmetic Ingredient Review expert panel has endorsed the European guidelines.4,6 Further, the North American Contact Dermatitis Group has pointed out that parabens continue to demonstrate the lowest prevalence of positivity (0.6%) of any major preservative available on the North American market, which includes over 10,000 cosmetic and personal care products, and remain one of the safest classes of preservatives for the skin.14 Further, the FDA has listed or classified parabens as generally regarded as safe.8
Safety of parabens
Parabens do not accumulate in tissues or organs for any appreciable length of time.6,8 In addition, carcinogenicity, cytotoxicity, or mutagenicity has not been proven in relation to parabens.8 Indeed, classical assays have shown no activity from parabens in terms of mutagenicity or carcinogenicity.11,15 Some estrogenic effects or activity that mimics estrogen have been associated with parabens in vitro, but this activity has been noted as very weak and there are no established reports of human cases in which parabens have elicited an estrogen-mediated adverse event.6,11
Concerns about a possible link between parabens and breast cancer have been largely diminished or relegated to the status of unknown and difficult to ascertain.13 Further, present knowledge provides no established link between the topical application of parabens-containing skin care formulations on healthy skin and cancer risk.10 Only intact skin should come in touch with products containing parabens to prevent irritant reactions.
Conclusion
Despite the fearful hype and reaction to one report 15 years ago, parabens continue to be safely used in numerous topical formulations. Their widespread use and lack of association with adverse events are a testament to their safety. From a dermatologic perspective, this nonallergen of the year deserves a better reputation.
Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote two textbooks: “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and “Cosmeceuticals and Cosmetic Ingredients” (New York: McGraw-Hill, 2014), and a New York Times Best Sellers book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Evolus, Galderma, and Revance. She is the founder and CEO of Skin Type Solutions Franchise Systems. Write to her at dermnews@mdedge.com
References
1. “Goodman and Gilman’s The Pharmacological Basis of Therapeutics,” 6th ed. (New York: Macmillan, 1980, p. 969).
2. Toxicity: The Butyl, Ethyl, Methyl, and Propyl Esters have been found to promote allergic sensitization in humans, in “Dangerous Properties of Industrial Materials,” 4th ed. (New York: Van Nostrand Reinhold, 1975, p. 929).
3. Food Chem Toxicol. 2001 Jun;39(6):513-32.
4. Dermatitis. 2014 Sep-Oct;25(5):215-31.
5. Crit Rev Toxicol. 2005 Jun;35(5):435-58.
6. Int J Toxicol. 2008;27 Suppl 4:1-82.
7. Food Chem Toxicol. 2002 Oct;40(10):1335-73.
8. Dermatitis. 2019 Jan/Feb;30(1):3-31.
9. Exp Dermatol. 2007 Oct;16(10):830-6.
10. J Appl Toxicol. 2004 Jan-Feb;24(1):5-13.
11. Dermatitis. 2019 Jan/Feb;30(1):32-45.
12. Food Chem Toxicol. 2005 Feb;43(2):279-91.
13. Dermatitis. 2018 Dec 18. doi: 10.1097/DER.0000000000000429.
14. Dermatitis. 2018 Nov/Dec;29(6):297-309.
15. Food Chem Toxicol. 2005 Jul;43(7):985-1015.
Parabens were named nonallergen of the year! It is time that we help consumers understand that the substitutes for parabens are often worse than parabens, and parabens are not as sensitizing as we thought. Preservatives are essential parts of most cosmetics and cosmeceuticals. (I say “most” because many organic products do not have them and consequently have shorter shelf lives.) Without them, products are vulnerable to rapid decomposition and infiltration by bacteria, fungi, and molds. The preservatives that are used in the place of parabens often are sensitizers. What do we tell our patients about the safety of parabens with all of these conflicting reports? This column will focus on current thoughts regarding the safety of parabens used as preservatives. I would love to hear your thoughts.
Background
Parabens are alkyl esters of p-hydroxybenzoic acid and have been used as a class of preservatives since the late 1920s and early 1930s. Parabens are found naturally in raspberries, blackberries, carrots, and cucumbers and are common ingredients in food and pharmaceuticals. They are still widely used in skin, hair, and body care products, despite the public outcry against them.1-4
There are many kinds of parabens such as butylparaben, isobutylparaben, ethylparaben, methylparaben, propylparaben, isopropylparaben, and benzylparaben, each with its own characteristics.5 Parabens are considered ideal preservative ingredients because they exhibit a broad spectrum of antimicrobial activity, stability over a large pH and temperature range, have no odor, do not change color, and are water soluble enough to yield an effective concentration in a hydrophilic formulation.3 As the alkyl chain length of parabens increases, they become less water soluble and more oil soluble. Parabens penetrate the skin barrier in inverse relation to its ester chain length.6 Often, several parabens will be combined to take advantage of each paraben’s solubility characteristics.
Many patients avoid parabens because of “health risks.” Now other preservatives are being substituted for parabens, even though these ingredients may be less studied or even less safe than parabens. It is important not to lump all parabens together as they each have different characteristics. Methylparaben and propylparaben are the most commonly used parabens in skin care products.7 Combinations of parabens are notably more effective than the use of single parabens.3,8 High concentrations of any type of paraben can cause an irritant reaction on the skin, but those with longer ester chain lengths are more likely to cause irritation.
Methylparaben
The methyl ester of p-hydroxybenzoic acid is found in many skin care products. It is readily absorbed through the skin and gastrointestinal tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body. Studies have shown it is nontoxic, nonirritating, and nonsensitizing. It is not teratogenic, embryotoxic, or carcinogenic. Methylparaben, because of its shorter side chain groups and greater lipophilicity, has been shown to be more readily absorbed by the skin than other paraben chemicals.8,9 It is also on the low order of ingredients provoking acute and chronic toxicity.3
Propylparaben
Propylparaben is the ester form of p-hydroxybenzoic acid that has been esterified with n-propanol. It is the most commonly used antimicrobial preservative in foods, cosmetics, and drugs. It is readily absorbed through the skin and GI tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body.
Estrogenic activity of parabens
In a 2004 study, Darbre et al. reported on the discovery of parabens-like substances in breast tissue and published these findings in the Journal of Applied Toxicology.10 The media and public panicked, saying that parabens have estrogenic activity and can cause breast cancer. However, many studies have shown that certain parabens do not have estrogenic activity. Although some parabens have been shown to impart estrogenic effects in vitro, these are very weak. The four most commonly used parabens in cosmetic products are 10,000-fold or less potent than 17beta-estradiol.11 The potential to result in an adverse effect mediated via an estrogen mode of action has not been established in humans.6 Paraben exposure differs geographically. No correlation has been found between the amount of parabens in a geographic location and the incidence of breast cancer. Current scientific knowledge is insufficient to demonstrate a clear cancer risk caused by the topical application of cosmetics that contain parabens on normal intact skin.11
Parabens and contact dermatitis
Paraben compounds are capable of minimal penetrance through intact skin.12 When they are able to penetrate the skin – a capacity that varies among the class – parabens are rapidly metabolized to p-hydroxybenzoic acid and promptly excreted in the urine.3,11 Parabens for many years were thought to cause contact dermatitis, and there are many reports of this. However, the incidence is much lower than previously thought. In fact, parabens were named “Nonallergen of the Year in 2018” because of the low incidence of reactions in patch tests.13 Higher concentrations of parabens applied topically to skin – especially “nonintact” skin – have been shown to cause mild irritant reactions. It is likely that many of these reported cases of “contact dermatitis” were actually irritant dermatitis. Longstanding concerns about the allergenicity of parabens in relation to the skin have been rendered insignificant, as the wealth of evidence reveals little to no support for the cutaneous toxicity of these substances.11 Yim et al. add that parabens remain far less sensitizing than agents newly introduced for use in personal care products.4
Daily average exposure to parabens
It is estimated that parabens are found in 10% of personal care products. In most cases, these products contain 1% or less of parabens. If the average patient uses 50 g of personal care products a day, then the average daily exposure to parabens topically is 0.05 g. Parabens also are found in food and drugs, so the total paraben exposure per day is assumed to be about 1 mg/day. (See the 2002 Food and Chemical Toxicology article for details of how this was calculated.)7 When food, personal care products, and drug exposure rates are added, the average person is exposed to 1.29 mg/kg per day or 77.5 mg/day for a 60-kg individual. You can see that personal care products account for a fraction of exposure, as most paraben exposure comes from food.
Government opinion on the safety of parabens for the skin
Parabens long have been assessed as safe for use in cosmetic products in many countries. The European Commission stipulated a maximum concentration of 0.4% for each paraben and 0.8% for total mixture of paraben esters.4,6 While the Federal Food, Drug, and Cosmetic Act of 1938 prohibits the Food and Drug Administration from ruling on cosmetic ingredients, the industry-sponsored Cosmetic Ingredient Review expert panel has endorsed the European guidelines.4,6 Further, the North American Contact Dermatitis Group has pointed out that parabens continue to demonstrate the lowest prevalence of positivity (0.6%) of any major preservative available on the North American market, which includes over 10,000 cosmetic and personal care products, and remain one of the safest classes of preservatives for the skin.14 Further, the FDA has listed or classified parabens as generally regarded as safe.8
Safety of parabens
Parabens do not accumulate in tissues or organs for any appreciable length of time.6,8 In addition, carcinogenicity, cytotoxicity, or mutagenicity has not been proven in relation to parabens.8 Indeed, classical assays have shown no activity from parabens in terms of mutagenicity or carcinogenicity.11,15 Some estrogenic effects or activity that mimics estrogen have been associated with parabens in vitro, but this activity has been noted as very weak and there are no established reports of human cases in which parabens have elicited an estrogen-mediated adverse event.6,11
Concerns about a possible link between parabens and breast cancer have been largely diminished or relegated to the status of unknown and difficult to ascertain.13 Further, present knowledge provides no established link between the topical application of parabens-containing skin care formulations on healthy skin and cancer risk.10 Only intact skin should come in touch with products containing parabens to prevent irritant reactions.
Conclusion
Despite the fearful hype and reaction to one report 15 years ago, parabens continue to be safely used in numerous topical formulations. Their widespread use and lack of association with adverse events are a testament to their safety. From a dermatologic perspective, this nonallergen of the year deserves a better reputation.
Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote two textbooks: “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and “Cosmeceuticals and Cosmetic Ingredients” (New York: McGraw-Hill, 2014), and a New York Times Best Sellers book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Evolus, Galderma, and Revance. She is the founder and CEO of Skin Type Solutions Franchise Systems. Write to her at dermnews@mdedge.com
References
1. “Goodman and Gilman’s The Pharmacological Basis of Therapeutics,” 6th ed. (New York: Macmillan, 1980, p. 969).
2. Toxicity: The Butyl, Ethyl, Methyl, and Propyl Esters have been found to promote allergic sensitization in humans, in “Dangerous Properties of Industrial Materials,” 4th ed. (New York: Van Nostrand Reinhold, 1975, p. 929).
3. Food Chem Toxicol. 2001 Jun;39(6):513-32.
4. Dermatitis. 2014 Sep-Oct;25(5):215-31.
5. Crit Rev Toxicol. 2005 Jun;35(5):435-58.
6. Int J Toxicol. 2008;27 Suppl 4:1-82.
7. Food Chem Toxicol. 2002 Oct;40(10):1335-73.
8. Dermatitis. 2019 Jan/Feb;30(1):3-31.
9. Exp Dermatol. 2007 Oct;16(10):830-6.
10. J Appl Toxicol. 2004 Jan-Feb;24(1):5-13.
11. Dermatitis. 2019 Jan/Feb;30(1):32-45.
12. Food Chem Toxicol. 2005 Feb;43(2):279-91.
13. Dermatitis. 2018 Dec 18. doi: 10.1097/DER.0000000000000429.
14. Dermatitis. 2018 Nov/Dec;29(6):297-309.
15. Food Chem Toxicol. 2005 Jul;43(7):985-1015.
Parabens were named nonallergen of the year! It is time that we help consumers understand that the substitutes for parabens are often worse than parabens, and parabens are not as sensitizing as we thought. Preservatives are essential parts of most cosmetics and cosmeceuticals. (I say “most” because many organic products do not have them and consequently have shorter shelf lives.) Without them, products are vulnerable to rapid decomposition and infiltration by bacteria, fungi, and molds. The preservatives that are used in the place of parabens often are sensitizers. What do we tell our patients about the safety of parabens with all of these conflicting reports? This column will focus on current thoughts regarding the safety of parabens used as preservatives. I would love to hear your thoughts.
Background
Parabens are alkyl esters of p-hydroxybenzoic acid and have been used as a class of preservatives since the late 1920s and early 1930s. Parabens are found naturally in raspberries, blackberries, carrots, and cucumbers and are common ingredients in food and pharmaceuticals. They are still widely used in skin, hair, and body care products, despite the public outcry against them.1-4
There are many kinds of parabens such as butylparaben, isobutylparaben, ethylparaben, methylparaben, propylparaben, isopropylparaben, and benzylparaben, each with its own characteristics.5 Parabens are considered ideal preservative ingredients because they exhibit a broad spectrum of antimicrobial activity, stability over a large pH and temperature range, have no odor, do not change color, and are water soluble enough to yield an effective concentration in a hydrophilic formulation.3 As the alkyl chain length of parabens increases, they become less water soluble and more oil soluble. Parabens penetrate the skin barrier in inverse relation to its ester chain length.6 Often, several parabens will be combined to take advantage of each paraben’s solubility characteristics.
Many patients avoid parabens because of “health risks.” Now other preservatives are being substituted for parabens, even though these ingredients may be less studied or even less safe than parabens. It is important not to lump all parabens together as they each have different characteristics. Methylparaben and propylparaben are the most commonly used parabens in skin care products.7 Combinations of parabens are notably more effective than the use of single parabens.3,8 High concentrations of any type of paraben can cause an irritant reaction on the skin, but those with longer ester chain lengths are more likely to cause irritation.
Methylparaben
The methyl ester of p-hydroxybenzoic acid is found in many skin care products. It is readily absorbed through the skin and gastrointestinal tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body. Studies have shown it is nontoxic, nonirritating, and nonsensitizing. It is not teratogenic, embryotoxic, or carcinogenic. Methylparaben, because of its shorter side chain groups and greater lipophilicity, has been shown to be more readily absorbed by the skin than other paraben chemicals.8,9 It is also on the low order of ingredients provoking acute and chronic toxicity.3
Propylparaben
Propylparaben is the ester form of p-hydroxybenzoic acid that has been esterified with n-propanol. It is the most commonly used antimicrobial preservative in foods, cosmetics, and drugs. It is readily absorbed through the skin and GI tract. It is quickly hydrolyzed and excreted in the urine and does not accumulate in the body.
Estrogenic activity of parabens
In a 2004 study, Darbre et al. reported on the discovery of parabens-like substances in breast tissue and published these findings in the Journal of Applied Toxicology.10 The media and public panicked, saying that parabens have estrogenic activity and can cause breast cancer. However, many studies have shown that certain parabens do not have estrogenic activity. Although some parabens have been shown to impart estrogenic effects in vitro, these are very weak. The four most commonly used parabens in cosmetic products are 10,000-fold or less potent than 17beta-estradiol.11 The potential to result in an adverse effect mediated via an estrogen mode of action has not been established in humans.6 Paraben exposure differs geographically. No correlation has been found between the amount of parabens in a geographic location and the incidence of breast cancer. Current scientific knowledge is insufficient to demonstrate a clear cancer risk caused by the topical application of cosmetics that contain parabens on normal intact skin.11
Parabens and contact dermatitis
Paraben compounds are capable of minimal penetrance through intact skin.12 When they are able to penetrate the skin – a capacity that varies among the class – parabens are rapidly metabolized to p-hydroxybenzoic acid and promptly excreted in the urine.3,11 Parabens for many years were thought to cause contact dermatitis, and there are many reports of this. However, the incidence is much lower than previously thought. In fact, parabens were named “Nonallergen of the Year in 2018” because of the low incidence of reactions in patch tests.13 Higher concentrations of parabens applied topically to skin – especially “nonintact” skin – have been shown to cause mild irritant reactions. It is likely that many of these reported cases of “contact dermatitis” were actually irritant dermatitis. Longstanding concerns about the allergenicity of parabens in relation to the skin have been rendered insignificant, as the wealth of evidence reveals little to no support for the cutaneous toxicity of these substances.11 Yim et al. add that parabens remain far less sensitizing than agents newly introduced for use in personal care products.4
Daily average exposure to parabens
It is estimated that parabens are found in 10% of personal care products. In most cases, these products contain 1% or less of parabens. If the average patient uses 50 g of personal care products a day, then the average daily exposure to parabens topically is 0.05 g. Parabens also are found in food and drugs, so the total paraben exposure per day is assumed to be about 1 mg/day. (See the 2002 Food and Chemical Toxicology article for details of how this was calculated.)7 When food, personal care products, and drug exposure rates are added, the average person is exposed to 1.29 mg/kg per day or 77.5 mg/day for a 60-kg individual. You can see that personal care products account for a fraction of exposure, as most paraben exposure comes from food.
Government opinion on the safety of parabens for the skin
Parabens long have been assessed as safe for use in cosmetic products in many countries. The European Commission stipulated a maximum concentration of 0.4% for each paraben and 0.8% for total mixture of paraben esters.4,6 While the Federal Food, Drug, and Cosmetic Act of 1938 prohibits the Food and Drug Administration from ruling on cosmetic ingredients, the industry-sponsored Cosmetic Ingredient Review expert panel has endorsed the European guidelines.4,6 Further, the North American Contact Dermatitis Group has pointed out that parabens continue to demonstrate the lowest prevalence of positivity (0.6%) of any major preservative available on the North American market, which includes over 10,000 cosmetic and personal care products, and remain one of the safest classes of preservatives for the skin.14 Further, the FDA has listed or classified parabens as generally regarded as safe.8
Safety of parabens
Parabens do not accumulate in tissues or organs for any appreciable length of time.6,8 In addition, carcinogenicity, cytotoxicity, or mutagenicity has not been proven in relation to parabens.8 Indeed, classical assays have shown no activity from parabens in terms of mutagenicity or carcinogenicity.11,15 Some estrogenic effects or activity that mimics estrogen have been associated with parabens in vitro, but this activity has been noted as very weak and there are no established reports of human cases in which parabens have elicited an estrogen-mediated adverse event.6,11
Concerns about a possible link between parabens and breast cancer have been largely diminished or relegated to the status of unknown and difficult to ascertain.13 Further, present knowledge provides no established link between the topical application of parabens-containing skin care formulations on healthy skin and cancer risk.10 Only intact skin should come in touch with products containing parabens to prevent irritant reactions.
Conclusion
Despite the fearful hype and reaction to one report 15 years ago, parabens continue to be safely used in numerous topical formulations. Their widespread use and lack of association with adverse events are a testament to their safety. From a dermatologic perspective, this nonallergen of the year deserves a better reputation.
Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote two textbooks: “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and “Cosmeceuticals and Cosmetic Ingredients” (New York: McGraw-Hill, 2014), and a New York Times Best Sellers book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Evolus, Galderma, and Revance. She is the founder and CEO of Skin Type Solutions Franchise Systems. Write to her at dermnews@mdedge.com
References
1. “Goodman and Gilman’s The Pharmacological Basis of Therapeutics,” 6th ed. (New York: Macmillan, 1980, p. 969).
2. Toxicity: The Butyl, Ethyl, Methyl, and Propyl Esters have been found to promote allergic sensitization in humans, in “Dangerous Properties of Industrial Materials,” 4th ed. (New York: Van Nostrand Reinhold, 1975, p. 929).
3. Food Chem Toxicol. 2001 Jun;39(6):513-32.
4. Dermatitis. 2014 Sep-Oct;25(5):215-31.
5. Crit Rev Toxicol. 2005 Jun;35(5):435-58.
6. Int J Toxicol. 2008;27 Suppl 4:1-82.
7. Food Chem Toxicol. 2002 Oct;40(10):1335-73.
8. Dermatitis. 2019 Jan/Feb;30(1):3-31.
9. Exp Dermatol. 2007 Oct;16(10):830-6.
10. J Appl Toxicol. 2004 Jan-Feb;24(1):5-13.
11. Dermatitis. 2019 Jan/Feb;30(1):32-45.
12. Food Chem Toxicol. 2005 Feb;43(2):279-91.
13. Dermatitis. 2018 Dec 18. doi: 10.1097/DER.0000000000000429.
14. Dermatitis. 2018 Nov/Dec;29(6):297-309.
15. Food Chem Toxicol. 2005 Jul;43(7):985-1015.