Gomesin
A tarantula antimicrobial peptide — a rigid disulfide beta-hairpin that disrupts the membranes of microbes and cancer cells. Research compounds, not drugs
Gomesin comes from the blood cells of the Brazilian tarantula Acanthoscurria gomesiana, which is where it gets its name. Structurally it is a close cousin of the horseshoe-crab peptide tachyplesin and the pig peptide protegrin: a short, strongly cationic beta-hairpin locked into shape by two disulfide bonds. That rigid, charged scaffold lets gomesin bind and break microbial membranes, giving it broad activity against Gram-positive and Gram-negative bacteria, fungi (especially Candida) and parasites. What has drawn the most recent attention, though, is that gomesin also selectively disrupts the membranes of cancer cells, which has made it a scaffold for anticancer and drug-delivery research. Chemists have built cyclic versions of gomesin that survive in blood, slip into cancer cells and kill bacterial biofilms, turning the natural peptide into a stable template for drug design. Gomesin and its analogs are research peptides; they are not approved medicines and have not been given to people as an approved treatment.
No established human dose Details ↓
Recommended Dosing
No established human dose
Gomesin is a spider research peptide; no gomesin is an approved treatment, and its cyclic analogs are investigational scaffolds. The work here is in microbes, cultured cells and animals, often with engineered analogs, at experimental amounts that do not carry over to people, so no amount is printed here.
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What is it?
Spiders, like horseshoe crabs and pigs, defend themselves with potent beta-hairpin antimicrobial peptides, and gomesin is the best-studied example. It was isolated in 2000 from the blood cells (haemocytes) of the Brazilian tarantula Acanthoscurria gomesiana, and its discoverers immediately noted how much it resembled the horseshoe-crab tachyplesins. Gomesin is eighteen residues, strongly cationic, and folded into a beta-hairpin pinned by two disulfide bonds, with a modified (pyroglutamate) start and an amidated end that add to its stability — the same rigid architecture seen in tachyplesin, protegrin and arenicin.
Gomesin's reach is unusually broad. It is active against Gram-positive and Gram-negative bacteria, is especially effective against pathogenic fungi such as Candida, and also hits parasites. Research into gomesin-like peptides has sought variants with cleaner, more selective antifungal profiles: one short, histidine-rich analog from a spider (DsGom) matched natural gomesin's antifungal activity against Candida while being far less toxic to human cells, pointing toward safer antifungal leads.
What sets gomesin apart from many antimicrobial peptides is its activity against cancer cells. It selectively targets and disrupts the membranes of tumour cells, and recent work has mapped why: gomesins bind membranes with a particular phospholipid and cholesterol makeup, and their toxicity to melanoma is tied to the glycosphingolipid pathway (the ST3GAL5 gene) and to intracellular cholesterol, with cholesterol-poor melanoma cells being the most sensitive. Its membrane mechanism is distinctive: rather than punching classic stable pores, the wedge-shaped peptide makes the outer membrane layer bulge and fold until it suddenly tears — a different route to the same lethal end.
Because the natural peptide is relatively fragile in blood, most translational work uses engineered versions. A cyclic gomesin is far more stable in human serum, can enter cancer cells by both direct membrane crossing and uptake, and has been used as a scaffold to carry drugs; a designed cyclic analog cleared established Staphylococcus aureus biofilms, which are notoriously hard to treat — and in both cases the three-dimensional structure and its disulfide bonds proved essential, since linear, unfolded versions were inactive. These cyclic and D-amino-acid analogs are the forms being pursued for anticancer, anti-infective and delivery applications.
Through all of this, gomesin remains a research peptide. No gomesin is an approved medicine, and its analogs are investigational scaffolds; material sold online under this name is an unregulated research chemical. Nothing here is a dose or a therapy; this page records what the published science says.
Mechanism of Action
Gomesin is an 18-residue cationic beta-hairpin spider (tarantula) antimicrobial peptide, stabilised by two disulfide bonds, that binds and breaks the membranes of bacteria, fungi, parasites and cancer cells — not by classic stable pores but by inducing membrane protrusion, folding and laceration. Its selectivity for cancer cells and its serum-stable cyclic analogs make it a scaffold for anticancer, antibiofilm and drug-delivery research.
Tarantula host defense
An 18-residue cationic beta-hairpin stabilised by two disulfide bonds, from the haemocytes of the spider Acanthoscurria gomesiana; akin to the tachyplesins (PMID 36982972).
Membrane disruption
Binds and breaks microbial and cancer-cell membranes by inducing lipid domains, protrusion and laceration rather than stable pores, with activity against bacteria, fungi and parasites (PMIDs 31510749, 39771584).
Anticancer and engineered scaffolds
Selectively disrupts cancer-cell membranes (melanoma, via the glycosphingolipid pathway); serum-stable cyclic analogs enter cancer cells, clear biofilms and carry drugs (PMIDs 41271646, 32979382, 36171717).
Published Research
These are studies of gomesin read from their PubMed records on November 7, 2026: how gomesins kill melanoma cells through the glycosphingolipid pathway and cholesterol, with a melanoma xenograft; natural gomesin-like peptides with more selective antifungal activity (DsGom); a review of gomesin's discovery, structure-activity relationships and therapeutic potential; a cyclic gomesin analog against Staphylococcus aureus biofilms; cyclic gomesin entering cancer cells as a drug scaffold; and how gomesin breaks membranes by protrusion and laceration rather than classic pores. The evidence is in microbes, cells and animals; no gomesin is an approved treatment.
How gomesins kill melanoma cells: the glycosphingolipid pathway and cholesterol
Using lipidomics, CRISPR screening, biophysics and a melanoma xenograft, spider gomesins (AgGom and HiGom) were shown to disrupt melanoma membranes with a specific phospholipid and cholesterol makeup; their toxicity ran through the glycosphingolipid pathway (ST3GAL5), and cholesterol-poor melanoma cells were most sensitive — mapping a route to targeted melanoma therapies (a preclinical study).
Gomesin-like peptides with more selective antifungal activity
Natural gomesin-like peptides were mined and produced recombinantly; a short, histidine-rich spider analog (DsGom) matched natural gomesin's antifungal activity against Candida while being much less toxic to human cells and remaining stable, making it a promising antifungal lead (an in-vitro study).
Gomesin: discovery, structure-activity relationships and therapeutic potential
A review describes gomesin as a cationic beta-hairpin peptide from tarantula haemocytes, toxic to bacteria, fungi, parasites and cancer cells, and highlights a cyclic version that is more serum-stable and can enter cancer cells, positioning gomesin as a lead for cancer and infectious-disease drug design (a review).
A cyclic gomesin analogue against Staphylococcus aureus biofilms
A designed cyclic gomesin analog killed cells embedded in 24-hour Staphylococcus aureus biofilms by permeabilising their membranes; analogs without the disulfide bonds or without the folded structure were inactive, showing that the stabilised three-dimensional shape is essential for antibiofilm activity (an in-vitro study).
Cyclic gomesin enters cancer cells as a drug scaffold
Cyclic gomesin, a disulfide-rich spider host-defence peptide that selectively targets cancer cell membranes, was shown to enter cancer cells by both uptake and direct membrane crossing; a redesigned non-disruptive, non-toxic D-amino-acid version kept that cell-entering ability and could serve as a scaffold to deliver drugs (an in-vitro study).
Gomesin disrupts membranes by protrusion and laceration
Microscopy and computer simulations showed that gomesin does not form classic stablepores; instead the wedge-shaped peptide binds the membrane, makes the outer layer protrude and fold, and triggers sudden tears — a membrane-breaking mechanism distinct from the pore-forming peptide melittin (an in-vitro and computational study).
No Established Human Dose
Gomesin is a spider research peptide; no gomesin is an approved treatment, and its cyclic analogs are investigational scaffolds. The work here is in microbes, cultured cells and animals, often with engineered analogs, at experimental amounts that do not carry over to people, so no amount is printed here.
What this rests on: PMID 41271646, PMID 36171717, PMID 39771584.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Gomesin is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
Unknown: no human dose of Gomesin has been established (see No Established Human Dose below), so there is no amount to work out. The reconstitution calculator does the arithmetic for any vial, water and dose.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Gomesin, before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Gomesin stays intact once mixed.
How it is taken
Unknown: with no established human dose, there is no established way of taking Gomesin. What the human studies gave and how is set out under No Established Human Dose.
What to expect, and when
How long it stays in the body: a half-life of not established for humans; natural gomesin is relatively short-lived in serum, while cyclic analogs are markedly more serum-stable. After about five half-lives almost none is left.
When effects appear: unknown; no source on this page gives a time to effect for Gomesin. Results reported in the studies are under Published Research.
Source: half-life: PMID 32979382.
Side effects, and when to stop or get help
From the Side Effects section: No approved-treatment human safety data exist for gomesin; Natural gomesin is toxic to some human cells at active concentrations; engineered analogs (DsGom, D-amino-acid cyclic gomesin) are designed to reduce that toxicity (PMIDs 39771584, 32979382) — research findings, not approved-drug data; Its activity against cancer cells is being explored deliberately (PMID 41271646), which also means effects on host cells must be weighed in any development; Material sold online as 'gomesin' is an unregulated research chemical of unverified content. Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Gomesin. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“Gomesin is a research peptide and no gomesin is an approved treatment, so there is no established human safety profile; the points below reflect that status and its biology”).
Interactions
Unknown: a PubMed search for human interaction studies of Gomesin (reviewed 2026-11-07) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Gomesin products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Research Chemical (Not an approved drug: Drugs@FDA and the openFDA label endpoint hold no record, and FDA GSRS and ChEMBL hold no approved-drug record for gomesin (searched November 7, 2026)). Sport: Not on the 2026 List.
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
Gomesin is a research peptide and no gomesin is an approved treatment, so there is no established human safety profile; the points below reflect that status and its biology.
Contraindications & Cautions
Gomesin has no approved use and no label. These points reflect its research status.
Legal Status
Gomesin is a tarantula antimicrobial peptide used as a research compound; it is not an approved drug in any country.
Frequently Asked Questions
?What is gomesin?
An antimicrobial peptide from the blood cells of the Brazilian tarantula Acanthoscurria gomesiana. It is an 18-amino-acid cationic beta-hairpin held by two disulfide bonds, first described in 2000, with a structure similar to the horseshoe-crab tachyplesins (PMID 36982972).
?How does it work?
It binds and breaks the membranes of bacteria, fungi, parasites and cancer cells — not by forming classic stable pores but by making the membrane protrude, fold and tear (PMIDs 31510749, 39771584).
?Why is it studied for cancer?
Gomesin selectively disrupts cancer-cell membranes; its toxicity to melanoma runs through the glycosphingolipid pathway and cholesterol, and serum-stable cyclic versions can enter cancer cells and carry drugs (PMIDs 41271646, 32979382).
?Is it approved or available to buy?
No. Gomesin is not an approved medicine, has no FDA application or label, and is approved nowhere; its analogs are investigational. Material sold online as gomesin is an unregulated research chemical. Grey Peptides lists no sellers and recommends no source; this page records the published science.
References
- [animal] Fernandez-Carrasco I, et al. "The cytotoxicity of gomesin peptides is mediated by the glycosphingolipid pathway and lipid-cholesterol interactions." Cell Death Discov, 2025;11(1):538. PMID: 41271646.
- [mechanism] Bolosov IA, et al. "Natural Gomesin-like Peptides with More Selective Antifungal Activities." Pharmaceutics, 2024;16(12). PMID: 39771584.
- [review] Liu X, et al. "Unlocking the Potential of the Antimicrobial Peptide Gomesin: From Discovery and Structure-Activity Relationships to Therapeutic Applications." Int J Mol Sci, 2023;24(6). PMID: 36982972.
- [mechanism] Dias SA, et al. "A designed cyclic analogue of gomesin has potent activity against Staphylococcus aureus biofilms." J Antimicrob Chemother, 2022;77(12):3256-3264. PMID: 36171717.
- [mechanism] Benfield AH, et al. "Cyclic gomesin, a stable redesigned spider peptide able to enter cancer cells." Biochim Biophys Acta Biomembr, 2021;1863(1):183480. PMID: 32979382.
- [mechanism] Zhang S, et al. "Peripheral Antimicrobial Peptide Gomesin Induces Membrane Protrusion, Folding, and Laceration." Langmuir, 2019;35(40):13233-13242. PMID: 31510749.
- [other] Gomesin is an 18-residue cysteine-rich antimicrobial peptide isolated from the haemocytes of the Brazilian tarantula Acanthoscurria gomesiana, first described by Silva, Daffre, Bulet and colleagues (J Biol Chem, 2000), who noted its sequence similarity to the horseshoe-crab tachyplesins. Its structure, activities and engineered analogs are described in the studies carded on this page (read November 7, 2026).
- [other] US FDA, Drugs@FDA and the openFDA label endpoint, searched November 7, 2026: no application and no label record for gomesin. It is a spider research peptide, not an approved drug; FDA GSRS and ChEMBL hold no approved-drug record for it.
Sources & Citations
The six studies carded above were read from their PubMed records on November 7, 2026. Gomesin's tarantula (Acanthoscurria gomesiana haemocyte) origin, its 18-residue two-disulfide beta-hairpin structure, its membrane-disrupting mechanism (protrusion and laceration rather than classic pores), its activity against bacteria, fungi, parasites and cancer cells, and its serum-stable cyclic analogs for anticancer, antibiofilm and drug-delivery research are from the studies carded here; the discovery is Silva, Daffre, Bulet et al. (J Biol Chem, 2000). The absence of US approval or a drug record from Drugs@FDA, openFDA, FDA GSRS and ChEMBL was checked the same day. Grey Peptides sells nothing and links to no vendor.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.