Nisin

nisin A, E234 (food-additive number), Nisaplin (commercial preparation); a lantibiotic from Lactococcus lactis

Antimicrobial & antiviral

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Summary

Class: Naturally occurring 34-amino-acid lantibiotic (a lanthionine-containing, post-translationally modified peptide) produced by Lactococcus lactis
Mechanism: Binds lipid II (the bacterial cell-wall building block), both blocking wall synthesis and using lipid II as a docking point to punch pores in the membrane
Routes studied: Oral/ingested as a food preservative (approved); topical, dental and veterinary (mastitis) uses studied; not an injected human drug
Half-life: Degraded by digestive enzymes when ingested; not systemically active orally
Storage: Stable dry powder, more stable at acidic pH; food-grade preparations are shelf-stable
Regulatory status: Approved food additive (E234) in the EU, US (GRAS) and ~50+ countries; not an approved medicine

Doses are as reported in studies or by the community — never recommendations.

1What it is

Nisin is a natural antibacterial peptide made by the dairy bacterium Lactococcus lactis. It belongs to the lantibiotics — peptides that carry unusual ring-forming amino acids (lanthionine and methyl-lanthionine) built in after the chain is made. Nisin has been used since the late 1960s as a food preservative (additive number E234), especially in cheese and processed meats, to suppress spoilage and dangerous Gram-positive bacteria including Clostridium botulinum and Listeria. It is one of the oldest and most widely approved antimicrobial peptides in the world — but as a food additive, not a medicine.

People eat it routinely and safely. Its medical interest (wound care, dental, mastitis, possible gut-pathogen use) is active research, not established therapy, and there is no community injectable use.

2How it's thought to work

Lipid II binding. nisin latches onto lipid II, the molecule bacteria use to build their cell wall. This both blocks wall synthesis and anchors nisin so it can assemble pores.

Pore formation. anchored at lipid II, nisin molecules punch holes in the membrane, collapsing the ion and pH gradients the cell needs and killing it rapidly.

Spore activity. it is also effective against bacterial spores, which is why it is valued against Clostridium in food.

Gram-negative limitation. the outer membrane of Gram-negative bacteria usually shields them unless it is disrupted (heat, EDTA), limiting nisin's spectrum.

A bacteriocin from lactic acid bacteria that binds lipid II, a cell-wall building block, and uses it as a docking point to punch pores. Used as a food preservative for decades.Schematic — not to scale

3What the research shows

Graded A (regulatory)

Food preservation safety

Decades of use plus toxicology underpin regulatory acceptance. EFSA's re-evaluation set an acceptable daily intake of 1 mg nisin A/kg body weight/day, based on a 90-day rat study with a no-adverse-effect level of 225 mg/kg/day and a 200-fold safety factor, and judged dietary exposure well below that. This is high-quality safety evidence for ingestion.

Graded B/C

Mastitis and veterinary/topical antiseptic use

Nisin-based teat wipes and mastitis products have been studied in dairy cattle, and nisin has been tested as a topical antiseptic and in wound and dental applications in animals and small human studies, with some positive antibacterial results.

Graded C/D

Medical anti-infective research

Laboratory and animal work explores nisin (and engineered nisin variants) against resistant Gram-positives (MRSA, enterococci), biofilms, and — combined with agents that breach the outer membrane — some Gram-negatives. Interest includes combination with miconazole for Clostridioides difficile. None is an approved human therapy, and oral nisin is digested before it could act systemically.

Oral/gut and dental

Studied for oral-cavity bacteria and as a possible gut-targeted antimicrobial; early-stage.

4Reported side effects and interactions

Literature-reported

As a food additive, nisin has an excellent safety record; no significant toxicity at dietary levels, and the oral NOAEL in rats was very high. Allergy is rare.

Community-reported

Community use as a medicine/injectable: essentially none documented. People consume it in food without issue.

Theoretical. concerns centre on possible cross-resistance with other lipid II-targeting antibiotics and on the fact that eaten nisin is simply digested — a limitation, not a toxicity.

Interactions. none established at dietary exposure.

Markers researchers commonly monitor

No human therapeutic monitoring is established because nisin is a food additive, not an administered medicine. In food-safety science the relevant work is dietary-exposure modelling against the ADI rather than individual biomarkers. For any experimental topical/medical use, general local tolerability is the main observation.

Free for everyone. Safety information is never behind a paywall.

5Formulation and handling

Supplied as a food-grade powder (e.g. Nisaplin, standardised with salt/milk solids); handled as a food ingredient, not a injectable. No calculator link applies.

6Commonly studied alongside

EDTA and other outer-membrane permeabilisers (to extend reach to Gram-negatives), conventional antibiotics (combination studies), other lantibiotics and antimicrobial peptides such as the Human defensins.

Informational cross-links. Not stack recommendations.

7Regulatory status by region

Region	Status (checked —)
United States	GRAS for specified food uses (FDA); not an approved drug
European Union	Approved food additive E234, with an ADI of 1 mg/kg bw/day
United Kingdom	Permitted food additive (retained EU rules)
Australia	Permitted food additive (FSANZ)
South Africa	Permitted as a food preservative
Sport	Not listed by WADA; not a performance substance

8Open questions

Can engineered nisin variants or delivery systems make it a viable medical antibiotic despite digestion and the Gram-negative barrier?
Does nisin select for cross-resistance with clinically important lipid II-targeting antibiotics?
Is there a real niche for nisin in human infection (gut, dental, wound) beyond food?

9References

1EFSA ANS Panel (2017). Safety of nisin (E 234) as a food additive in the light of new toxicological data and the proposed extension of use. EFSA Journal. PubMed
2Hsu ST et al. (2004). The nisin–lipid II complex reveals a pyrophosphate cage that provides a blueprint for novel antibiotics. Nat Struct Mol Biol. PubMed · DOI
3Shin JM et al. (2016). Biomedical applications of nisin. J Appl Microbiol. PubMed · DOI
4Field D et al. (2015). Bioengineered nisin derivatives with enhanced activity. (review). Front Microbiol. PubMed

References are being resolved to PubMed/DOI identifiers; links search PubMed for the citation until then.

10Community

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Self-reported side effects Phase 2

Not enough data yet. 0 of the 50 members needed have logged this compound for 4+ weeks. We don't show anything below 50, so no one can be identified.

11Page history

30 Oct 2026Profile published — awaiting medical review

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