Pentigetide (IgE Pentapeptide)
A five-amino-acid peptide from the tail of IgE, trialled as an allergy nasal spray and eye drop in the 1980s-90s. Human trials suggested benefit, but its IgE-blocking mechanism was never confirmed and it was never approved
Pentigetide — known in the older literature as the human IgE pentapeptide (HEPP) or the Hamburger pentapeptide, and trialled under the brand Pentyde — is a tiny synthetic peptide of just five amino acids (Asp-Ser-Asp-Pro-Arg). Its sequence was reported to match a short stretch of the constant (Fc) region of IgE, the antibody that drives allergic reactions. The idea was elegant: a fragment of IgE might compete with whole IgE for its receptors on mast cells and basophils, blocking the trigger of hay fever, allergic conjunctivitis and other type-I allergic responses. In human trials in the 1980s and early 1990s, pentigetide given as a nasal solution or eye drops did reduce allergy symptoms compared with placebo, and compared favourably with cromolyn in one eye-allergy study. But the science did not hold together: when several independent laboratories tried to reproduce the proposed mechanism, they could not show that the pentapeptide actually blocks IgE from binding its receptors, and concluded the effect was 'of no clinical relevance'. Pentigetide was never approved by any regulator and its development was abandoned. It is included here as a documented, instructive example of an investigational allergy peptide whose clinical signal outran its mechanism — not as a treatment.
No established human dose Details ↓
Recommended Dosing
No established human dose
Pentigetide was given to people only inside clinical trials of an investigational, never-approved drug, as topical formulations (a nasal solution and eye drops) applied under study supervision; the exact trial regimens, with their sources, are in the studies below. Those are regimens for an abandoned agent, not guidance: there is no approved product, no established current dose, and no amount is printed here for use.
Work out syringe units → · New to syringes? · All dosing data ↓ · Dose and vial tracker · Is this vial OK?
What is it?
Allergic reactions such as hay fever are driven by IgE antibodies bound to receptors on mast cells and basophils: when an allergen cross-links that IgE, the cells release histamine and other mediators. In the 1970s the idea arose that a small peptide copying a piece of the IgE molecule might act as a decoy, competing with whole IgE for its receptors and so preventing this trigger. Pentigetide — the pentapeptide Asp-Ser-Asp-Pro-Arg, drawn from a reported sequence in the constant region of the IgE heavy (epsilon) chain — was that peptide, developed as the anti-allergy agent Pentyde.
The clinical results were encouraging. In a multicentre randomised, double-blind trial of 431 patients with seasonal allergic rhinitis, pentigetide nasal solution gave a statistically significant reduction in the frequency and severity of nasal symptoms versus placebo, with a side-effect profile no different from placebo. A randomised trial in allergic conjunctivitis found pentigetide eye drops improved several ocular signs and symptoms more than cromolyn sodium, and earlier double-blind, placebo-controlled studies in allergic rhinitis and in IgE-mediated atopic disease had also reported symptom benefit.
The mechanism, however, could not be confirmed. A collaboration of four laboratories testing the central claim found no evidence — by autoradiography or histamine-release assays — that the pentapeptide blocks IgE from binding basophils and mast cells, displaces bound IgE, or impairs antigen-induced histamine release; at pentapeptide-to-IgE ratios of a million to ten million, there was simply no competition, and the authors judged any weak affinity to be of no clinical relevance. An independent study of the 'reputed' inhibition saw only partial, inconsistent effects in Prausnitz-Küstner skin testing and a baboon model, and failed to demonstrate that the peptide actually displaces mast-cell-bound IgE.
This left a genuine puzzle — modest symptom improvement in controlled trials, but no verified mechanism — and pentigetide was never approved and was abandoned. It stands as a useful case study in reading the evidence critically: a positive clinical signal does not by itself establish that a compound works the way its proponents claim, and an unconfirmed mechanism plus failure to reach approval is an important part of the record.
Pentigetide is an unapproved investigational peptide, not a medicine. It is approved nowhere, there is no established current dose, and anything sold under its names is an unregulated research chemical. Grey Peptides lists no sellers and recommends no source; this page records what the published trials and mechanism studies actually found.
Mechanism of Action
Pentigetide is the pentapeptide Asp-Ser-Asp-Pro-Arg, drawn from a reported IgE epsilon-chain sequence. The hypothesis was that it competes with IgE for mast-cell/basophil receptors to block allergic reactions; human trials suggested symptom benefit, but independent laboratories could not confirm that it blocks IgE, so the mechanism remains unestablished.
Proposed IgE-receptor competition (unconfirmed)
The design rationale was that an IgE-derived pentapeptide would compete with IgE at its mast-cell and basophil receptors (PMID 415986), but a four-laboratory study found no such competition and no block of IgE binding or histamine release (PMID 67091).
Observed symptom benefit (mechanism unclear)
In controlled human trials, topical pentigetide reduced allergic-rhinitis and conjunctivitis symptoms versus placebo (PMIDs 1952297, 3578925) and compared favourably with cromolyn (PMID 1903616) — an effect not explained by the proposed mechanism.
Published Research
These are studies of pentigetide (the human IgE pentapeptide, Pentyde) read from their PubMed records on November 7, 2026. They include two randomised human trials and two earlier controlled human trials that reported symptom benefit in allergic rhinitis and conjunctivitis, and two mechanism studies — a four-laboratory collaboration and an independent investigation — that could NOT confirm the proposed IgE-receptor-blocking mechanism. The entry presents both sides; the peptide was never approved.
Pentigetide nasal solution reduces seasonal-allergic-rhinitis symptoms (RCT)
A randomised, multicentre, double-blind, placebo-controlled trial in 431 patients with seasonal allergic rhinitis gave pentigetide (Pentyde) nasal solution four times daily for two weeks. Pentigetide produced a statistically significant greater reduction in the frequency (p=.004) and severity (p=.05) of total nasal symptoms (sneezing, congestion, rhinorrhoea) than placebo, with consistently lower daily diary scores and an adverse-event profile like placebo (no sedation). A positive human interventional result.
Pentigetide eye drops vs cromolyn for allergic conjunctivitis (RCT)
A randomised, double-blind, parallel-group trial (50 patients) compared pentigetideophthalmic solution with cromolyn sodium over two weeks in allergic conjunctivitis. Both physicians and patients rated the pentigetide group significantly more improved overall, with greater improvement in hyperaemia, oedema, lacrimation and itching; mean symptom severity fell 64% with pentigetide vs 46% with cromolyn, and adverse events were minor in both arms. An active-controlled human result.
Intranasal IgE pentapeptide beats placebo in allergic rhinitis
A double-blind, placebo-controlled trial in 30 patients with IgE-mediated allergic rhinitis found statistically and clinically significant improvement with intranasal IgE pentapeptide (HEPP) solution versus placebo, and reported the peptide to be safe — an earlier controlled human signal of symptom benefit.
Human IgE pentapeptide in IgE-mediated atopic disease
A controlled study in 12 patients with IgE-mediated atopic disease reported statistically significant differences in allergy symptom scores, allergy-medication use and skin-test results between human IgE pentapeptide (HEPP) and placebo, and judged the peptide safe — one of the first human evaluations, with a small sample.
Four labs find the IgE pentapeptide does NOT compete with IgE (mechanism)
A collaboration of four laboratories tested the central claim that the pentapeptide blocks IgE-mediated allergy by competing for basophil/mast-cell IgE receptors. By autoradiography it did not block IgE fixation or displace bound IgE; by histamine-release assays it did not block sensitisation, remove IgE from sensitised cells, or impair antigen-induced histamine release; and it did not block Prausnitz-Küstner skin testing. At pentapeptide:IgE ratios of 10^6-10^7 there was no competition, judged 'of no clinical relevance' — a strong negative mechanism result.
'Reputed' P-K inhibition by Asp-Ser-Asp-Pro-Arg is partial and unconvincing (mechanism)
An investigation of the reputed inhibitory activity of the pentapeptide Asp-Ser-Asp-Pro-Arg in the human Prausnitz-Küstner and baboon passive-cutaneous-anaphylaxis systems saw only partial inhibition of wealing in some recipients at a very low intradermal dose, and in-vivo forearm tests in grass-pollen-sensitive people failed to provide convincing evidence that the peptide displaces mast-cell-bound IgE antibody — an equivocal mechanism result.
No Established Human Dose
Pentigetide was given to people only inside clinical trials of an investigational, never-approved drug, as topical formulations (a nasal solution and eye drops) applied under study supervision; the exact trial regimens, with their sources, are in the studies below. Those are regimens for an abandoned agent, not guidance: there is no approved product, no established current dose, and no amount is printed here for use.
What this rests on: PMID 1952297, PMID 1903616, PMID 3578925.
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 Pentigetide (IgE Pentapeptide) 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 Pentigetide (IgE Pentapeptide) 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 Pentigetide (IgE Pentapeptide), 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 Pentigetide (IgE Pentapeptide) stays intact once mixed.
How it is taken
Unknown: with no established human dose, there is no established way of taking Pentigetide (IgE Pentapeptide). 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; a short synthetic pentapeptide given topically in trials. After about five half-lives almost none is left.
When effects appear: unknown; no source on this page gives a time to effect for Pentigetide (IgE Pentapeptide). Results reported in the studies are under Published Research.
Source: half-life: PMID 1952297.
Side effects, and when to stop or get help
From the Side Effects section: In the 431-patient rhinitis RCT, adverse events were similar to placebo, with no sedation or fatigue (PMID 1952297); In the conjunctivitis trial, adverse events were minor and comparable to cromolyn, with no abnormal changes in visual acuity or intraocular pressure (PMID 1903616); Human data are limited to short, topical use in trials of a drug that was never approved and whose mechanism was not confirmed; No safety data support any non-topical or self-directed use; material sold under its names 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 Pentigetide (IgE Pentapeptide). Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“The clinical trials carded here reported pentigetide, given topically, to be well tolerated”).
Interactions
Unknown: a PubMed search for human interaction studies of Pentigetide (IgE Pentapeptide) (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 Pentigetide (IgE Pentapeptide) 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 approved: Drugs@FDA and the openFDA label endpoint hold no approved application or label for pentigetide / Pentyde (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
The clinical trials carded here reported pentigetide, given topically, to be well tolerated. It is an unapproved investigational peptide with no consumer safety profile.
Contraindications & Cautions
Pentigetide has no approved use and no drug label. These points reflect its investigational, abandoned status.
Legal Status
Pentigetide (Pentyde) is an unapproved investigational peptide once trialled for allergy; it is not an approved drug in any country.
Frequently Asked Questions
?What is pentigetide?
A synthetic five-amino-acid peptide (Asp-Ser-Asp-Pro-Arg), also called the human IgE pentapeptide (HEPP) and trialled as Pentyde. Its sequence was reported from the constant region of IgE, and it was developed as an anti-allergy agent.
?Did it work for allergies?
Controlled human trials of topical pentigetide reported reduced allergic-rhinitis and conjunctivitis symptoms versus placebo (PMIDs 1952297, 3578925) and a favourable comparison with cromolyn (PMID 1903616). However, independent laboratories could not confirm that it actually blocks IgE (PMID 67091), and it was never approved.
?Why was it abandoned?
The proposed mechanism — competing with IgE at mast-cell/basophil receptors — could not be reproduced, leaving a modest clinical signal with no verified explanation, and the drug never gained approval. It is a cautionary example of a clinical result outrunning its mechanism.
?Is it approved or available to buy?
No. Pentigetide is not approved anywhere and its development was discontinued; it was only ever given in clinical trials. Material sold under its names is an unregulated research chemical. Grey Peptides lists no sellers and recommends no source.
References
- [rct] Mansmann HC Jr, et al. "Pentigetide nasal solution: a multicenter study evaluating efficacy and safety in patients with seasonal allergic rhinitis." Ann Allergy, 1991;67(4):409-15. PMID: 1952297.
- [rct] Kalpaxis JG, et al. "Double-blind trial of pentigetide ophthalmic solution, 0.5%, compared with cromolyn sodium, 4%, ophthalmic solution for allergic conjunctivitis." Ann Allergy, 1991;66(5):393-8. PMID: 1903616.
- [clinical-trial] Prenner BM. "Double-blind placebo-controlled trial of intranasal IgE pentapeptide." Ann Allergy, 1987;58(5):332-5. PMID: 3578925.
- [clinical-trial] Cohen GA, et al. "Safety and efficacy of human IgE pentapeptide." Ann Allergy, 1984;52(2):83-6. PMID: 6364896.
- [mechanism] Bennich H, et al. "Failure of the putative IgE pentapeptide to compete with IgE for receptors on basophils and masts cells." Int Arch Allergy Appl Immunol, 1977;53(5):459-68. PMID: 67091.
- [mechanism] Stanworth DR, et al. "Investigation of the reputed inhibition of the Prausnitz-Küstner reaction by the pentapeptide Asp-Ser-Asp-Pro-Arg." Int Arch Allergy Appl Immunol, 1978;56(5):409-15. PMID: 415986.
- [other] UniProt P01854 (IGHE, immunoglobulin heavy constant epsilon), read November 7, 2026: pentigetide is a synthetic pentapeptide, Asp-Ser-Asp-Pro-Arg, whose sequence was reported to correspond to a portion of the constant (Fc) region of the human IgE heavy (epsilon) chain — the basis for the idea that it might compete with IgE at its receptors. https://www.uniprot.org/uniprotkb/P01854/entry
- [other] Pentigetide — the 'human IgE pentapeptide' (HEPP), also called the Hamburger pentapeptide and marketed in trials as Pentyde by Immunetech Pharmaceuticals — was proposed in the 1970s-80s as an anti-allergy agent that would block IgE from binding mast-cell and basophil receptors. The proposed mechanism and the clinical results are both covered by the studies carded on this page (read November 7, 2026); naming the developer is for context only, Grey Peptides lists no seller.
- [other] US FDA, Drugs@FDA and the openFDA label endpoint, searched November 7, 2026: no approved application and no drug label for pentigetide (Pentyde). It reached multicentre clinical trials for allergic rhinitis and conjunctivitis in the late 1980s-early 1990s but was never approved, and development was discontinued; it is an unapproved investigational peptide.
Sources & Citations
The six studies carded above were read from their PubMed records on November 7, 2026. Identity (the pentapeptide Asp-Ser-Asp-Pro-Arg, reported from the IgE epsilon chain) is from UniProt P01854 and the carded mechanism papers; the clinical results (allergic rhinitis and conjunctivitis trials) and the failure to confirm the IgE-blocking mechanism are from the trials and mechanism studies carded here; the absence of US approval was checked via Drugs@FDA and openFDA the same day. The developer (Immunetech Pharmaceuticals, brand Pentyde) is named for context only; 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.