Omiganan

omiganan pentahydrochloride, MBI-226, CLS001, MX-226, CLS-001

Antimicrobial & antiviral

Awaiting medical reviewEN ES DE FR PT ZH+ Follow for updates

1What it is

Omiganan is a synthetic antimicrobial peptide derived from indolicidin, a short tryptophan-rich host-defence peptide from cattle neutrophils. It has been developed as a topical agent — first as an antiseptic for the skin around intravascular catheters, and later (by Cutanea/Maruho and others) as a gel for inflammatory skin conditions where bacteria or the skin microbiome play a part, chiefly rosacea and acne, as well as atopic dermatitis, genital warts and vulvar intraepithelial neoplasia.

It has been through many trials over roughly two decades but has not reached approval. It is not a community self-use compound.

2How it's thought to work

Omiganan is cationic and attracted to microbial membranes, which it permeabilises, giving broad antibacterial and antifungal activity. In skin conditions the rationale is partly direct antimicrobial action against organisms implicated in rosacea and acne and partly a modulating effect on the skin microbiome and local inflammation. Because it is applied topically and barely absorbed, systemic exposure is minimal.

A synthetic indolicidin analogue applied to the skin. It kills by disrupting the microbial membrane rather than by hitting an enzyme, and is not absorbed.Schematic — not to scale

3What the research shows

Catheter-site colonisation

A large trial of topical omiganan (then MBI-226/MX-226) for preventing central-venous-catheter infection reduced local catheter-site colonisation but did not significantly reduce the key endpoint of catheter-related bloodstream infection, so it did not support approval.

Rosacea

Phase 2 work in papulopustular rosacea (e.g. a 240-patient study, omiganan 1% and 2.5% vs vehicle) showed signals favouring 2.5% once daily on some lesion-count measures but did not clearly meet the percent-change primary endpoint; the programme moved toward Phase 3 but did not deliver a clear approvable result.

Acne vulgaris

Phase 2 trials in acne reported some improvement versus vehicle; results were not strong enough to reach market.

Atopic dermatitis, genital warts, vulvar intraepithelial neoplasia

Exploratory Phase 2 studies (several run in the Netherlands) tested omiganan as a microbiome-modulating topical. Signals were mixed and none produced an approved indication. Across indications the pattern is consistent: tolerable, biologically plausible, repeated Phase 2 signals, but no definitive pivotal success.

4Reported side effects and interactions

Literature-reported

Topical omiganan was generally well tolerated, with local application-site reactions the main finding and negligible systemic exposure.

Community-reported

Community use: essentially none documented. This is an investigational prescription-type topical, not a self-use peptide.

Theoretical. minimal, given topical-only use.

Interactions. none established.

Markers researchers commonly monitor

Not applicable as a self-use compound. Trial endpoints were clinical (lesion counts and investigator global assessment in rosacea/acne; catheter colonisation and bloodstream infection) and local tolerability, not blood markers, reflecting topical use.

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

5Formulation and handling

Developed as a finished topical gel at defined strengths (1%, 2.5%); not a peptide for . No calculator link applies.

6Commonly studied alongside

Topical antibiotics and standard rosacea/acne therapies (as comparators), chlorhexidine (catheter-antiseptic comparator), other antimicrobial peptides such as Pexiganan (research context).

Informational cross-links. Not stack recommendations.

7Regulatory status by region

Region	Status (checked —)
United States	Not FDA-approved; investigational across dermatology and catheter indications
European Union	Not authorised
United Kingdom	Not licensed
Australia	Not approved
South Africa	Not registered
Sport	Not relevant; not listed by WADA

8Open questions

Can omiganan show a decisive Phase 3 benefit in any single dermatology indication, or will it stay a perennial Phase 2 molecule?
Is its effect in rosacea/acne antimicrobial, microbiome-modulating, anti-inflammatory, or a mix?
Does topical antimicrobial-peptide delivery reach the relevant skin compartments at active concentrations?

9References

1Sader HS et al. (2004). Omiganan pentahydrochloride (MBI 226): antimicrobial activity and spectrum. Antimicrob Agents Chemother. PubMed
2Melo MN, Castanho MARB (2007). Omiganan interaction with bacterial membranes and cell wall models. Biochim Biophys Acta. PubMed
3Niemeyer-van der Kolk T et al. (2020). Topical antimicrobial peptide omiganan in dermatology: Phase 2 studies (atopic dermatitis / rosacea). Clin Pharmacol Ther / Br J Dermatol. PubMed
4Cutanea Life Sciences (2016–2018). CLS001 (omiganan) rosacea Phase 2/3 programme announcements. 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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