E-numbers / Preservatives / E209
also: Heptyl paraben · Heptyl ester of p-hydroxybenzoic acid · INS 209
A synthetic paraben preservative not permitted in UK or EU food. Used in some US beverages to stop microbial spoilage.
Scan a barcode to check a food for heptylparaben. NutraSafe Pro · £3.99/month · iOS
Heptylparaben belongs to the paraben family, which mimic the hormone oestrogen.
Why it’s worth knowing. Heptylparaben belongs to the paraben family, which mimic the hormone oestrogen. Longer-chain parabens such as heptylparaben show stronger oestrogen-like activity in laboratory tests than shorter-chain relatives. Parabens have been detected intact in human breast tumour tissue, and chronic animal exposure at levels within human safety benchmarks accelerated tumour growth and spread in mice. It is not on the UK list of approved food additives, so you will not normally see this E number on a UK label.
Heptylparaben is the heptyl ester of para-hydroxybenzoic acid, a synthetic compound belonging to the paraben preservative family. Its International Numbering System code is INS 209. It has seven carbon atoms in its alkyl chain, making it a longer-chain paraben.
It disrupts microbial cell membranes and interferes with essential enzyme systems, preventing mould, yeast and bacterial growth in food and beverages. Like other parabens, it works across a wide pH range and inhibits spoilage at low concentrations.
Not permitted in UK or EU food. In the United States it is approved for use in fermented malt beverages such as beer (up to 12 parts per million) and in noncarbonated soft drinks and fruit-based beverages (up to 20 parts per million). On a US label it may appear as heptylparaben or heptyl p-hydroxybenzoate.
All parabens can bind to human oestrogen receptors, but the strength of this binding rises with each additional carbon in the alkyl chain. Heptylparaben, with a seven-carbon chain, shows among the most potent oestrogen receptor activity of all commonly studied parabens. Laboratory studies find it can drive oestrogen-receptor-mediated gene expression and promote breast cancer cell proliferation and migration in cell cultures.
Among 17 parabens tested, those with alkyl chains around C5-C7, including heptylparaben, showed the most potent oestrogenic activity at oestrogen receptors alpha and beta, with potency falling stepwise in shorter or longer chains.
Parabens show weak oestrogen-like activity in laboratory and animal tests and are classed as endocrine-disrupting chemicals, with estrogenic potency increasing as a function of alkyl chain length.
A 2004 study measured intact parabens in breast tumour samples from 20 patients. Methylparaben was the most abundant form detected. The authors were clear that detection does not establish that parabens caused the tumours, and called for further work comparing paraben levels in cancerous versus healthy breast tissue.
Parabens were detected intact in 20 human breast tumour samples at a mean concentration of 20.6 ng per gram of tissue. Methylparaben accounted for 62% of the total recovered.
A 2023 study dosed mice genetically predisposed to mammary tumours with methylparaben or propylparaben at levels equivalent to human acceptable daily intakes. Both parabens increased primary tumour volume and significantly raised the number of lung metastases compared with controls, with propylparaben producing a 91% increase in weekly metastases. The mice had an existing tumour predisposition, so findings cannot be transferred directly to healthy humans, but the doses were within recognised human safety thresholds.
Female mice exposed to methylparaben or propylparaben at doses within the FDA acceptable daily intake developed larger primary mammary tumours and 28% and 91% more weekly lung metastases respectively compared with unexposed controls.
Human population studies examining urinary paraben levels and breast cancer risk have returned inconsistent results. Some case-control studies find higher paraben exposure associated with increased breast cancer risk; others find weak inverse associations or no clear correlation. The overall epidemiological picture is limited and does not establish causation.
A systematic review concluded that epidemiological evidence linking paraben exposure to breast cancer remains limited, with individual studies finding contradictory directional associations.
Heptylparaben was never included in the EU positive list of approved food additives. The related parabens propylparaben (E216) and its sodium salt (E217) were removed from EU authorisation in 2006 after the European Food Safety Authority concluded that a safe exposure level for propylparaben could not be set, because of evidence of effects on male reproductive hormones and sperm production in young rats. Methyl and ethyl parabens (E214, E215, E218, E219) remain permitted with a group acceptable daily intake.
EFSA concluded in 2004 that an acceptable daily intake of 0-10 mg/kg body weight per day could be set for methyl and ethyl parabens and their sodium salts, but not for propylparaben, due to effects on male reproductive hormones in young rats. Propylparaben was subsequently removed from the EU approved additives list in 2006.
Anyone buying food in the UK and EU will not encounter E209 in authorised products. Those purchasing imported US beverages such as some beers, malt drinks or fruit-based soft drinks should look for heptylparaben or heptyl p-hydroxybenzoate on the ingredient list. People with known paraben sensitivity or allergy should also avoid this ingredient.
Heptylparaben is absent from UK and EU shelves as a permitted food ingredient. The paraben family carries a live scientific debate: laboratory studies consistently show oestrogen-like activity that rises with chain length, and heptylparaben sits near the top of that potency scale among food-relevant parabens. A 2023 animal study found that chronic exposure to related parabens at levels within human safety limits accelerated tumour growth in mice already prone to cancer. Human population data are inconsistent and cannot currently establish a causal link to cancer. The EU removed two related parabens from food use in 2006 because a safe level could not be confirmed for one of them; heptylparaben never entered the EU approved list at all. What this means for long-term human health from the relatively modest dietary exposures seen in the US context is not settled.
E209 heptylparaben is not on the UK FSA approved-additives list and was never authorised for use in food in the UK or EU. It therefore cannot legally be used as a food additive in UK food products. It is not the same as being actively banned after withdrawal, but the effect is the same: it is not permitted.
Estrogenic potency in parabens rises with alkyl chain length. Heptylparaben has a seven-carbon chain, which laboratory studies show places it among the most potent parabens for binding to human oestrogen receptors. Shorter-chain parabens such as methylparaben and ethylparaben bind more weakly. The full consequences of this stronger binding for human health are not yet established, but the pattern has informed regulatory decisions to keep longer-chain parabens out of food.
In the UK and EU, no authorised food product will contain E209, as it is not a permitted additive. In the United States it can appear in fermented malt beverages (including some beers) and noncarbonated soft drinks or fruit-based beverages. On a US label it would be listed as heptylparaben or heptyl p-hydroxybenzoate.
Heptylparaben is a synthetic compound manufactured from para-hydroxybenzoic acid and heptanol. It does not derive from animal sources and is generally considered vegan in composition. However, animal studies have been used to assess its toxicity.
Last reviewed: 20 June 2026
It's the only app that does thisUKJaneK
You Need This AppGmac2005
Best AppGK getting skinny UK App Store reviews
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
NutraSafe Pro · £3.99/month · iOS
