{"url":"https://whatshealthyandwhy.com/triclosan/overview","path":"/triclosan/overview","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/triclosan/overview.json","markdown":"https://whatshealthyandwhy.com/triclosan/overview.md"},"topic":{"slug":"triclosan","name":"Triclosan","url":"https://whatshealthyandwhy.com/triclosan"},"slug":"overview","order":1,"title":"Triclosan: The Antibacterial Chemical FDA Banned From Soap","question":"Is triclosan harmful, and is antibacterial soap better than plain soap?","answer":"Triclosan soap works no better than plain soap, and triclosan may disrupt thyroid hormones, though human evidence is limited to modest associations.","description":"An endocrine-disrupting antibacterial that's no more effective than plain soap — restricted by the FDA in 2016 but still found in toothpaste, plastics, and textiles","confidence":2,"confidenceNote":"Harm rests on cell and mouse studies plus modest NHANES associations (1,831 people); the no-benefit finding rests on a 27-study review.","evidenceSummary":{"rctCount":0,"observationalCount":3,"metaAnalysisCount":1,"totalParticipants":"4,500+","replicated":true,"newestStudyYear":2017},"category":{"categoryTitle":"What's Harming You","categorySlug":"harming-you","subcategoryName":"Environmental Toxins","subcategorySlug":"environment","url":"https://whatshealthyandwhy.com/explore/harming-you/environment"},"actions":["Wash hands with plain soap and water for 20 seconds, scrubbing between fingers and under nails; antibacterial soap was no better [4].","Check toothpaste and product labels for triclosan (also sold as Microban or Biofresh) and skip antibacterial-labeled items unless prescribed.","Skip antimicrobial-treated kitchen tools, yoga mats, athletic clothing and shower curtains."],"cautions":["The 2016 FDA rule covered only consumer antiseptic washes; it did not cover toothpaste, textiles, plastics or healthcare antiseptics [8].","Triclosan reaches the fetus (detected in cord blood) during sensitive development windows, so avoiding it in pregnancy is a sensible precaution [5].","Human evidence is modest: NHANES links urinary triclosan to lower thyroxine mainly in adolescents, but cannot show cause [7]."],"simpleText":"Triclosan is a synthetic antibacterial chemical that was added to thousands of consumer products — soaps, body washes, toothpaste, deodorants, cosmetics, plastics, even kitchen utensils — for decades before researchers realized it acts as an endocrine disruptor in the body and offers no real benefit over plain soap and water [4][8]. The FDA banned it from over-the-counter consumer antiseptic washes in 2016 after manufacturers failed to demonstrate it was both safe for long-term daily use and more effective than washing with regular soap [8]. Despite the partial ban, triclosan still appears in some toothpaste, textiles, and plastics, and it has been detected in roughly three-quarters of Americans' urine [3].","mediumText":"What Triclosan Does in the Body\n\nTriclosan was originally developed as a hospital surgical scrub in the 1960s. Once industry began adding it to consumer products, large-scale exposure became inevitable — it absorbs through skin and the lining of the mouth, then enters the bloodstream within minutes. The 2003-2004 NHANES biomonitoring survey detected triclosan in 74.6% of urine samples from Americans aged six and older, with the highest levels measured in people in their twenties and in higher-income households [3].\n\nEndocrine disruption\n\nTriclosan resembles thyroid hormone and several other steroid hormones in its molecular structure. In cell and animal studies it interferes with thyroid signaling, estrogen receptors, and androgen receptors. A NHANES analysis of 2007-2008 urinary triclosan and serum thyroid measures found higher triclosan exposure was associated with altered total thyroxine (T4) levels, particularly in adolescents, suggesting the laboratory findings translate to detectable effects in the general population [7]. Thyroid hormone is essential for fetal brain development, metabolism, and energy regulation, making even modest disruption a concern.\n\nLiver effects\n\nA 2014 study in PNAS exposed mice to triclosan for six months — roughly equivalent to 18 human years of exposure — and found it strongly promoted liver tumor formation, accelerated fibrosis, and increased oxidative stress in liver cells [1]. The mechanism appears to involve interference with constitutive androstane receptor (CAR) signaling, a pathway that normally regulates how the liver handles xenobiotics. Mice given triclosan together with a chemical liver carcinogen developed larger and more numerous tumors than controls.\n\nAntibiotic resistance\n\nTriclosan kills bacteria by inhibiting an enzyme called enoyl-ACP reductase, the same broad target affected by some antibiotics. Years of household and consumer use of sub-lethal triclosan concentrations selects for resistant bacterial strains, and these strains often show cross-resistance to clinical antibiotics. A 2007 review in Clinical Infectious Diseases concluded that consumer triclosan soaps at typical concentrations (0.1-0.45%) were no more effective than plain soap at preventing illness or reducing bacterial counts on hands, while laboratory data showed they could select for antibiotic-resistant bacteria [4].\n\nWhere It Still Hides\n\nThe 2016 FDA rule applied only to consumer antiseptic washes used with water — bar soap, body wash, hand soap [8]. It did not cover:\n\n- Hand sanitizers\n- Healthcare antiseptics (hospital scrubs)\n- Toothpaste (Colgate Total contained triclosan until 2019, when Colgate voluntarily reformulated)\n- Textiles, kitchen sponges, cutting boards, plastics with antimicrobial claims\n- Cosmetics and deodorants in some formulations\n\nReading ingredient labels is the most reliable defense. Triclosan may also appear under chemical synonyms like 2,4,4'-trichloro-2'-hydroxydiphenyl ether or under the trade names Microban or Biofresh in non-cosmetic products. See our Personal Care Products page for guidance on auditing daily-use products.\n\nPractical reduction steps\n\n- Wash hands with plain soap and water — 20 seconds, full lather, scrub between fingers and under nails. The mechanical action of washing, not antibacterial chemistry, removes most pathogens.\n- Avoid products labeled \"antibacterial\" or \"antimicrobial\" unless prescribed.\n- Check toothpaste ingredient lists for triclosan; switch to fluoride or hydroxyapatite formulations without antimicrobials.\n- Skip antimicrobial-treated kitchen tools, yoga mats, athletic clothing, and shower curtains.\n\nWhy The Story Matters\n\nTriclosan is a case study in how a chemical can become ubiquitous before its biological effects are characterized. It was added to consumer products under the assumption that \"kills bacteria on contact\" translated to better health outcomes — an assumption that turned out to be wrong both at the population level (no benefit over plain soap) and at the cellular level (significant endocrine and liver effects). The Florence Statement, signed by more than 200 scientists in 2017, called for limiting use of triclosan and the closely related triclocarban to applications with demonstrated medical benefit, and for full disclosure on consumer products [2]. The same caution applies to many of the antimicrobial chemicals introduced as triclosan replacements.","deepText":"Evidence Review\n\nHuman exposure prevalence\n\nCalafat and colleagues (2008) analyzed 2,517 urine samples collected during the 2003-2004 NHANES cycle, the first nationally representative biomonitoring study to measure triclosan in the United States [3]. Triclosan was detected in 74.6% of samples at concentrations of 2.4-3,790 micrograms per liter, with a geometric mean of 13.0 micrograms per liter and a 95th percentile of 459.0 micrograms per liter. Concentrations were highest in people aged 20-29 and in households in the highest income quartile, an unusual exposure pattern explained by personal care product use rather than occupational exposure. The study established that triclosan exposure was nearly universal in the U.S. population, motivating subsequent investigation of health effects.\n\nThyroid hormone associations\n\nKoeppe and colleagues (2013) used NHANES 2007-2008 data — 1,831 participants with paired urinary triclosan/paraben measurements and serum thyroid hormone panels — to assess whether biomonitored exposure correlated with thyroid disruption [7]. After adjustment for age, sex, BMI, race, urinary creatinine, and serum cotinine, urinary triclosan was inversely associated with total thyroxine (T4) in adolescents, with stronger effects in girls. The effect size was modest at the population level but supports the mechanistic case from animal studies that triclosan interferes with thyroid hormone homeostasis.\n\nLiver toxicity in animal models\n\nYueh and colleagues (2014) fed mice a diet containing 0.09% triclosan — chosen to produce serum levels comparable to those measured in humans — for six months [1]. Compared to controls, triclosan-fed mice showed enhanced hepatocyte proliferation, increased markers of fibrosis, oxidative stress, and altered expression of hepatic genes related to xenobiotic metabolism. When the same mice received diethylnitrosamine to initiate hepatocarcinogenesis, triclosan accelerated tumor development: tumors were larger, more numerous, and appeared earlier than in controls. The authors traced the effect to triclosan's activation of constitutive androstane receptor (CAR), a nuclear receptor whose chronic stimulation is known to drive tumor promotion in rodents. Six months in mice corresponds roughly to 18 years of human exposure, raising concerns about cumulative effects given the duration of triclosan use in consumer products.\n\nEffectiveness vs. plain soap\n\nAiello, Larson, and Levy (2007) systematically reviewed 27 studies comparing antibacterial soap (containing 0.1-0.45% triclosan) to plain soap for two outcomes: bacterial reduction on hands and prevention of infectious illness symptoms [4]. Across community-setting studies, triclosan soaps were not significantly better than plain soap at reducing hand bacterial counts or preventing gastrointestinal and respiratory infections. The same review summarized laboratory evidence that bacteria exposed to sub-lethal triclosan concentrations developed mutations in the FabI enzyme, conferring resistance to triclosan and cross-resistance to several clinically important antibiotics. The combination — no measurable benefit, plausible harm — became the central evidentiary basis for the FDA's 2016 rulemaking.\n\nPregnancy and birth outcomes\n\nGeer and colleagues (2017) measured triclosan, triclocarban, and five paraben species in third-trimester maternal urine and umbilical cord blood from 185 mothers and 34 paired neonates in Brooklyn, New York (2007-2009) [5]. After adjustment for maternal age, BMI, parity, and gestational diabetes, triclocarban exposure was associated with shorter gestational age at birth, while butylparaben was independently associated with reduced birth weight and increased odds of preterm birth. Triclosan itself did not show statistically significant associations in this cohort. Cord blood detection confirms transplacental passage, meaning the fetus is directly exposed during sensitive windows of development.\n\nRegulatory and consensus assessments\n\nThe Florence Statement (Halden et al., 2017) is a consensus document signed by more than 200 scientists and medical professionals summarizing the evidence on triclosan and triclocarban [2]. The signatories concluded that both chemicals are environmentally persistent endocrine disruptors that bioaccumulate in aquatic organisms, generate toxic byproducts including dioxins and chlorophenols when degraded, and confer no demonstrated health benefit in consumer products. The statement called for restricting use to applications with documented medical benefit, full ingredient disclosure, and proactive evaluation of replacement chemicals to avoid simply substituting one antimicrobial for another with similar properties. Yueh and Tukey (2016) reviewed the broader evidence in the Annual Review of Pharmacology and Toxicology, drawing on in vitro and in vivo animal studies and environmental toxicology studies that show triclosan exerting adverse effects on different biological systems through various modes of action, and speculating that these effects may be relevant to human health [6].\n\nThe FDA's 2016 final rule (21 CFR Part 310) determined that triclosan and 18 other antimicrobials were neither generally recognized as safe nor effective for consumer antiseptic washes [8]. The agency cited insufficient long-term safety data, including unresolved questions about endocrine disruption and antibiotic resistance, alongside the absence of demonstrated benefit over plain soap. Manufacturers were given one year to comply, and triclosan was largely removed from U.S. consumer hand and body washes by September 2017. The rule did not address triclosan in toothpaste, healthcare settings, or non-drug products such as textiles, leaving meaningful exposure pathways open.\n\nStrength of evidence …","deepTruncated":true,"references":[{"id":"1","title":"The commonly used antimicrobial additive triclosan is a liver tumor promoter","authors":"Yueh MF, Taniguchi K, Chen S, Evans RM, Hammock BD, Karin M, Tukey RH","year":2014,"journal":"Proceedings of the National Academy of Sciences","pmid":"25404284","url":"https://pubmed.ncbi.nlm.nih.gov/25404284/"},{"id":"2","title":"The Florence Statement on Triclosan and Triclocarban","authors":"Halden RU, Lindeman AE, Aiello AE, Andrews D, Arnold WA, Fair P, Fuoco RE, Geer LA, Johnson PI, Lohmann R, McNeill K, Sacks VP, Schettler T, Weber R, Zoeller RT, Blum A","year":2017,"journal":"Environmental Health Perspectives","pmid":"28632490","url":"https://pubmed.ncbi.nlm.nih.gov/28632490/"},{"id":"3","title":"Urinary concentrations of triclosan in the U.S. population: 2003-2004","authors":"Calafat AM, Ye X, Wong LY, Reidy JA, Needham LL","year":2008,"journal":"Environmental Health Perspectives","pmid":"18335095","url":"https://pubmed.ncbi.nlm.nih.gov/18335095/"},{"id":"4","title":"Consumer antibacterial soaps: effective or just risky?","authors":"Aiello AE, Larson EL, Levy SB","year":2007,"journal":"Clinical Infectious Diseases","pmid":"17683018","url":"https://pubmed.ncbi.nlm.nih.gov/17683018/"},{"id":"5","title":"Association of birth outcomes with fetal exposure to parabens, triclosan and triclocarban in an immigrant population in Brooklyn, New York","authors":"Geer LA, Pycke BFG, Waxenbaum J, Sherer DM, Abulafia O, Halden RU","year":2017,"journal":"Journal of Hazardous Materials","pmid":"27156397","url":"https://pubmed.ncbi.nlm.nih.gov/27156397/"},{"id":"6","title":"Triclosan: A Widespread Environmental Toxicant with Many Biological Effects","authors":"Yueh MF, Tukey RH","year":2016,"journal":"Annual Review of Pharmacology and Toxicology","pmid":"26738475","url":"https://pubmed.ncbi.nlm.nih.gov/26738475/"},{"id":"7","title":"Relationship between urinary triclosan and paraben concentrations and serum thyroid measures in NHANES 2007-2008","authors":"Koeppe ES, Ferguson KK, Colacino JA, Meeker JD","year":2013,"journal":"Science of the Total Environment","pmid":"23340023","url":"https://pubmed.ncbi.nlm.nih.gov/23340023/"},{"id":"8","title":"Safety and Effectiveness of Consumer Antiseptics; Topical Antimicrobial Drug Products for Over-the-Counter Human Use; Final Rule","authors":"U.S. Food and Drug Administration","year":2016,"journal":"Federal Register","url":"https://www.federalregister.gov/documents/2016/09/06/2016-21337/safety-and-effectiveness-of-consumer-antiseptics-topical-antimicrobial-drug-products-for"}],"wordCount":1637,"source":{"path":"src/content/topics/triclosan/overview.md"},"citeAs":"“Is triclosan harmful, and is antibacterial soap better than plain soap?.” What's Healthy and Why. https://whatshealthyandwhy.com/triclosan/overview","notice":"General information backed by peer-reviewed research, not medical advice."}