Best Peptides for Immune Support

Educational content only — not medical advice. Consult a licensed healthcare provider before starting, changing, or stopping any peptide protocol.

Overview

Immune peptides are one of the most misunderstood categories in the space. The common framing — "boost your immune system" — is the wrong mental model. The compounds in this hub are studied as immunomodulators: signaling molecules intended to help a dysregulated immune system move toward a more normal set point.

That distinction matters, especially for people with autoimmune conditions or post-viral syndromes. A "boost" pushes the immune system harder in whatever direction it is already going, including the wrong one.

One compound here has substantially better human evidence than everything else on the page, and it is worth saying so up front. Thymosin alpha-1 is the only thymic peptide in this hub with multicentre randomized trial data — larazotide, further down, has its own randomized trials in celiac disease. In ETASS, 361 ICU patients with severe sepsis were randomized to Tα1 or control; 28-day all-cause mortality was 26.0% versus 35.0%, with a relative risk of 0.74 (95% CI 0.54 to 1.02), a non-stratified p value of 0.062 and a log-rank p of 0.049 (PMID 23327199).

Read that carefully, because it is usually reported as a win. The prespecified primary analysis did not reach significance (p = 0.062), the relative-risk confidence interval crosses 1, and the p = 0.049 comes from a log-rank analysis rather than the prespecified comparison. The authors' own conclusion is the appropriately hedged one: Tα1 "may be effective in improving clinical outcomes in a targeted population." That is the strongest result in this category, and it is a trial that missed its primary endpoint.

This hub covers the thymic peptides (thymosin alpha-1, thymulin, thymogen, thymalin), the antimicrobial peptides (LL-37, defensins), the α-MSH-derived anti-inflammatory KPV, VIP, the Russian immunological class, and the gut-immune axis peptides. If you are searching for "immune peptides," "peptides for autoimmune," "thymosin alpha-1," or "peptides for long COVID," start here.

Immunomodulation vs Immunostimulation

Peptides sit in the modulation column, but "modulation" still has direction. Thymosin alpha-1 acts through dendritic cell and Toll-like receptor pathways (PMID 16741252, PMID 17804687). KPV dampens inflammatory signalling (PMID 18092346). None of them is a blank cheque.

The Immune Peptide Families

A working model: thymic peptides act on T-cell maturation, antimicrobials act on pathogens, KPV and VIP dampen inflammatory signalling, and the gut-immune stack addresses the mucosal barrier. Note how the evidence column thins out as you go down.

Thymosin Alpha-1 — The Workhorse

Thymosin alpha-1 (Tα1) is the default immune peptide and the only thymic peptide here with multicentre randomized trial data — larazotide has its own randomized trials in celiac disease, further down this page. Marketed pharmaceutically as Zadaxin, it is licensed in a number of countries outside the US for indications including hepatitis B and as an adjunct in certain cancer settings. It is not FDA-approved in the United States. One naming trap is worth clearing up here: thymosin alpha-1 is not thymosin beta-4, whose active fragment is sold as TB-500 — that one is a tissue-repair compound, covered in the TB-500 Complete Guide and set against its usual counterpart in BPC-157 vs TB-500.

Mechanism, sourced

• Dendritic cell and tolerance signalling. Tα1 activates dendritic cell tryptophan catabolism and establishes a regulatory environment balancing inflammation and tolerance (PMID 16741252). Note the framing in that paper: balance, including tolerance, not one-directional stimulation.
• Toll-like receptor 9. Tα1 activates TLR9/MyD88/IRF7-dependent sensing of murine cytomegalovirus for induction of antiviral responses in vivo (PMID 17804687). That is the source of the "TLR9 agonist" claim, and it is a mouse finding.

What the human trials show

• Severe sepsis (ETASS). Multicentre, single-blind, randomized controlled trial in six Chinese teaching hospitals; 361 ICU patients with severe sepsis. 28-day all-cause mortality was 26.0% on Tα1 versus 35.0% in controls; relative risk 0.74 (95% CI 0.54 to 1.02); non-stratified p = 0.062, log-rank p = 0.049. Monocyte HLA-DR recovery was significantly better on Tα1 at day 3 and day 7, and no serious drug-related adverse event was recorded (PMID 23327199). The signal is real and the confidence interval touches 1 — read it as promising rather than established.
• Severe COVID-19. A retrospective review of 76 severe COVID-19 cases in two Wuhan hospitals found mortality of 11.11% with Tα1 versus 30.00% without (p = 0.044), along with restored CD8+ and CD4+ counts in patients with severe lymphocytopenia and reduced PD-1 and Tim-3 expression on CD8+ T cells (PMID 32442287). Retrospective, non-randomized, 76 patients — the mechanism data is the more interesting part.
• Vaccine response in older adults. A double-blind, placebo-controlled study reported augmentation of the influenza antibody response in elderly men given thymosin alpha-1 (PMID 2642497). The record here is mixed: an earlier study found that reduced interleukin-2 production in healthy older people did not correlate with antibody response to influenza vaccine and was not corrected in vitro by thymosin alpha-1 (PMID 2932408), and a separate paper examined age-related changes and thymosin's effect on influenza vaccine antibody response (PMID 6334692). A later review assessed Tα1's utility as an influenza vaccine co-adjuvant (PMID 22010537).

Typical use cases

Recurrent respiratory or viral infection, immunosenescence, post-viral fatigue syndromes, chronic viral reactivation, hepatitis B or C adjunct, and cancer adjuvant therapy under specialist supervision. Of those, sepsis and severe COVID are the two with published human outcome data, and neither is a wellness indication.

Dosing

Removed from this page. The milligram figure and frequency schedule that circulate for Tα1 reflect the pharmaceutical presentation used in clinical settings for approved indications abroad; reproducing them on a hub page would present practitioner convention as a dosing recommendation for an unapproved use. See the Thymosin Alpha-1 Protocol Guide, which carries the amounts with their sourcing, and take the decision with a clinician.

The Russian Thymic Peptides — Thymulin, Thymogen, Thymalin

Beyond Tα1 there is a Russian school of thymic peptide research, largely associated with Vladimir Khavinson and the St. Petersburg Institute of Bioregulation and Gerontology.

The thymulin–zinc relationship is the genuinely useful finding in this group, and it has a practical implication: if thymulin activity depends on zinc, then zinc status is worth checking before assuming a thymic peptide will do anything.

What to be honest about

• Evidence quality is substantially lower than for Tα1.
• Most studies are older, smaller, and published in Russian-language journals.
• Product variability is significant, so sourcing matters more than usual.
• The institute that developed them is also a commercial source.

Full deep dive: Thymulin, Thymogen & Thymalin Protocol Guide

LL-37 — The Antimicrobial, and the Autoimmune Problem

LL-37 is the only human cathelicidin antimicrobial peptide, produced by neutrophils, epithelial cells, and macrophages as part of innate defence.

What is established

• Biofilm prevention. The human host defence peptide LL-37 prevents bacterial biofilm formation (PMID 18591225), and its antibiofilm properties have been reviewed in depth (PMID 36781570). Note the verb: prevents formation, in vitro. That is not the same as dissolving an established biofilm in a human sinus or gut.
• Vitamin D dependence. Toll-like receptor triggering induces a vitamin D-mediated human antimicrobial response, in which vitamin D receptor signalling upregulates cathelicidin (PMID 16497887). This is the real basis for the vitamin D prerequisite — endogenous LL-37 production depends on it.

No clinical trial of exogenous LL-37 in humans for any infection was located. The entire case rests on the biology of the endogenous peptide.

The autoimmune caution is not theoretical

LL-37 is implicated as an autoantigen. In systemic lupus erythematosus, neutrophils activate plasmacytoid dendritic cells by releasing self-DNA–peptide complexes — LL-37 being the peptide that renders self-DNA immunogenic (PMID 21389263). LL-37 also appears among the autoantigens characterized in psoriasis (PMID 32697368), and its immunomodulatory role in autoimmune disease and viral infection has been reviewed (PMID 32927756). Separately, T cells reactive to LL-37 have been described in acute coronary syndrome and plaque calcification (PMID 33123157).

Putting that together: administering a peptide that acts as an autoantigen in lupus and psoriasis, to someone with active or latent autoimmunity, is a genuinely bad idea — and it is a mechanistic concern with primary literature behind it, not a defensive disclaimer. Anyone with a history of psoriasis, lupus, rheumatoid arthritis, or unexplained autoimmune markers should have a provider review baseline autoimmune labs before considering LL-37.

Full deep dive: LL-37 Protocol Guide. Its dated regulatory position sits on our tracker as cathelicidin LL-37.

KPV — The α-MSH-Derived Anti-Inflammatory

KPV is a tripeptide (Lys-Pro-Val) corresponding to the C-terminal sequence of α-melanocyte-stimulating hormone, α-MSH(11-13).

What the animal data shows

In two well-described murine models of inflammatory bowel disease — DSS colitis and CD45RB-high transfer colitis — KPV produced earlier recovery and significantly greater body weight regain, significantly reduced inflammatory infiltrates on colonic histology, and significantly reduced colonic myeloperoxidase activity. In mice with a non-functional melanocortin-1 receptor, KPV rescued all treated animals from death during DSS colitis, indicating the effect is at least partly MC1R-independent (PMID 18092346). Orally targeted delivery of KPV via functionalized nanoparticles also alleviated ulcerative colitis in mice (PMID 28143741).

That is good, specific mouse data. No human trial of KPV has been published, so the NF-κB and mast-cell-stabilization mechanisms often listed for it are inferences from the α-MSH literature rather than measured human effects, and they have been removed from this page as bullet-point facts.

Why KPV pairs with other things

Because its documented direction is anti-inflammatory rather than immunostimulating, KPV is the compound here least likely to aggravate an autoimmune condition — which is a mechanistic argument, not a safety finding. It is used alongside thymic peptides and antimicrobials on the reasoning that both can transiently increase inflammatory signalling.

Full deep dive: KPV Protocol Guide

VIP — What Is and Isn't Established

Vasoactive intestinal peptide is a 28-amino-acid neuropeptide with documented anti-inflammatory and immunoregulatory activity. VIP has been reviewed as a candidate approach for autoimmune therapy (PMID 17934101) and as one of a class of endogenous anti-inflammatory neuropeptides (PMID 18598752); it modulates T helper subset differentiation in rheumatoid arthritis (PMID 30155495) and induces tolerogenic dendritic cells that attenuated arthritis in collagen-induced arthritic mice (PMID 31062502).

So VIP's immunobiology is real and published. What is not published is the use it is best known for in this community.

In the peptide world VIP is most associated with Dr Ritchie Shoemaker's CIRS (Chronic Inflammatory Response Syndrome) protocol, as its final step. Two things need stating plainly. First, no randomized controlled trial of intranasal VIP for CIRS could be located on PubMed. Second, CIRS as Shoemaker defines it — a chronic multisystem inflammatory response to biotoxin exposure, characterized by a specific panel including C4a, TGF-β1, MMP-9, MSH and VIP — is not a diagnosis with general acceptance in mainstream immunology, and its marker panel is not a validated diagnostic standard.

None of that means people with mould exposure are not unwell. It means the protocol is a clinical framework rather than a trial-validated treatment, and this page should not describe it as more than that.

If you are pursuing it, the sequencing logic still holds within the framework: VIP sits last precisely because the earlier steps — removal from exposure, binder therapy, MARCoNS eradication, and normalization of the marker panel — are meant to be complete first, and using it early is reported to worsen symptoms. This is not a peptide to use independently. Work with a provider trained in the protocol who will monitor labs.

Full deep dive: VIP & CIRS Protocol Guide

Russian Immune Peptides — Imunofan and Splenopentin

The Russian immunological school developed a distinct class used in oncology adjunct therapy, chronic viral disease, and post-surgical recovery. Imunofan is described in terms of T-cell modulation, antioxidant signalling and hepatoprotection; splenopentin is a spleen-derived peptide described in terms of T- and B-cell modulation.

No English-language randomized trial of either compound was located on PubMed. The recurring pattern in this tradition is short courses of several days repeated a few times a year rather than continuous dosing. Western evidence is absent rather than merely thin, and that should be weighed against the fact that practitioners with international training do use them.

Full deep dive: Splenopentin & Imunofan Protocol Guide

Autoimmune Considerations — CRITICAL

This is the most important section on the page. If you have an autoimmune condition or suspect one, read it twice.

Why immune peptides carry risk in autoimmunity

Two distinct concerns, with different evidence behind them.

The one with primary literature: LL-37. It acts as an autoantigen. In lupus, LL-37 in complex with self-DNA released by neutrophils activates plasmacytoid dendritic cells and drives interferon production (PMID 21389263), and it appears among characterized psoriasis autoantigens (PMID 32697368). Giving more of it to someone whose immune system already targets it is a mechanistically specific risk.

The one that is inference: the thymic peptides. The common claim is that Tα1 enhances Th1 immunity and will therefore flare Th1-dominant autoimmune disease. That inference is worth taking seriously, but the primary literature is less one-directional than the claim: the dendritic cell paper describes Tα1 establishing "a regulatory environment for balance of inflammation and tolerance" (PMID 16741252), which is not a pure Th1 push. And ETASS, in 361 critically ill patients, recorded no serious drug-related adverse event (PMID 23327199).

The previous version of this page stated that "there are reports of Tα1 use coinciding with thyroid antibody elevation, joint flares, and neurological symptom worsening in susceptible individuals." No published case reports or case series establishing that could be located, so the claim has been removed. The honest position is that Tα1's effect in established autoimmune disease has not been studied, which is a reason for caution and provider oversight rather than a documented harm.

What to do with that uncertainty. No case series documents a specific autoimmune flare pattern for Tα1, and none is asserted here. Because its effect in established autoimmune disease is unstudied, treat any new or worsening autoimmune symptom — joint pain, unexplained fatigue, neurological change, or a shift in thyroid antibodies — as a reason to stop and consult the prescribing clinician, not as an expected part of the protocol.

Specific cautions

Before starting any immune peptide

A baseline autoimmune screen (ANA, RF, anti-CCP, TPO and thyroglobulin antibodies), a thyroid panel, inflammatory markers, and review by a physician. If any of those are abnormal, or if you have a family history of autoimmunity, the question changes from "which immune peptide" to "should I use one at all."

The Gut-Immune Axis

A large proportion of the body's immune cells reside in or near the gut, in the gut-associated lymphoid tissue and the mucosal lining. The specific "more than 70%" figure that used to appear here has been removed — it is widely repeated but no primary source for it was located, and a number that precise deserves a citation.

How the axis breaks down

1. Loss of barrier integrity. Tight junctions loosen, allowing antigens and bacterial fragments into circulation.
2. Chronic low-grade inflammation follows.
3. Dysbiosis skews immune education.
4. Mucosal immune dysfunction — secretory IgA falls, oral tolerance degrades.

The gut-immune peptide stack, with its actual evidence

Two consequences. Larazotide's dose response is inverted — more is worse, which is the opposite of most people's instinct. And the compound most associated with "fixing leaky gut" did not move the direct measure of intestinal permeability in pooled trials; its demonstrated effect is on symptoms. If your reason for taking it is a permeability number, the evidence does not support that reason.

See the Larazotide Protocol, BPC-157 Complete Guide, and KPV Protocol Guide. For where the FDA currently stands on the two research compounds in that table, the tracker carries dated rows for BPC-157 and KPV.

Protocol Structures

The frameworks below describe composition and sequencing. Doses and course lengths have been removed: apart from larazotide and the Zadaxin presentation, none of the figures that circulate for these compounds comes from a published human dose-finding study.

Every one of these assumes baseline labs, provider oversight, and quality-verified sourcing. See the Immune Support Protocol for the full framework, and the protocol library and safety library for the surrounding material.

Use Cases

Recurrent infections

Adults with frequent respiratory or urinary infections may have suboptimal T-cell or NK function — but that is a hypothesis to test with labs, not to assume. Tα1 is the most evidence-backed option, on the strength of the sepsis trial and the vaccine-response work, neither of which studied otherwise-healthy adults with frequent colds.

Immunosenescence

Thymic involution begins early in life and continues with age, and the thymic peptides are aimed at partially compensating. The specific figures about thymic output at particular ages that used to appear here have been removed as unsourced. The vaccine-response study in elderly men is the closest human evidence in this direction (PMID 2642497), with the caveats noted above.

Chronic Lyme adjunct

Lyme and co-infections can drive immune exhaustion, and biofilms are a recognized problem in chronic infection generally. LL-37 prevents biofilm formation in vitro (PMID 18591225); whether administering it disrupts an established biofilm in a person is untested. Any peptide use here is adjunct to evidence-based treatment, never a replacement.

Long COVID

An area of genuine clinical interest and thin evidence. Tα1's published COVID data is from a retrospective review of 76 acute severe hospitalized cases (PMID 32442287) — a different population from someone with persistent symptoms months later. The mechanistic finding that Tα1 reduced PD-1 and Tim-3 on CD8+ T cells is the part most relevant to the T-cell exhaustion hypothesis in long COVID, and it is a starting point for research rather than a treatment rationale.

Autoimmune disease

Some practitioners use KPV cautiously for its anti-inflammatory direction. Thymic peptides are generally avoided, and LL-37 should be avoided outright. See the autoimmune section.

Cancer adjuvant

Tα1 has been examined in oncology settings and has been reviewed for broader immuno-oncology applications (PMID 36871535). This is a domain for integrative oncologists working alongside an oncology team, not for self-experimentation.

What Immune Peptides Won't Do

• Not a substitute for diagnostics. Unexplained recurrent infection needs a workup — immunoglobulins and subclasses, lymphocyte subsets, vitamin D, complement, autoimmune screen. Peptides without a diagnosis is guessing.
• Not for acute infection. Bacterial pneumonia needs antibiotics; sepsis needs an ICU. Note that the sepsis trial — which missed its prespecified primary endpoint — gave Tα1 in addition to conventional therapy in an intensive care unit (PMID 23327199), which is the opposite of using it instead of care.
• Not a "boost." Nothing here has been shown to improve immune function in a healthy young person, and the framing of Tα1's mechanism in the primary literature is balance and tolerance, not amplification (PMID 16741252).
• Not a vaccine alternative. They do not generate antigen-specific immunity. The relevant study tried Tα1 as an adjunct to influenza vaccination (PMID 2642497).
• Not a cure for autoimmunity. At best some compounds modulate inflammation; none addresses the underlying dysregulation.
• Not a replacement for sleep, diet, or vitamin D. Vitamin D specifically: endogenous cathelicidin production depends on vitamin D receptor signalling (PMID 16497887), so correcting a deficiency is upstream of any antimicrobial peptide protocol.

Bloodwork & Monitoring

The point is not to chase numbers; it is to know your starting position and catch an adverse response early.

Baseline panel

CBC with differential; comprehensive metabolic panel; lymphocyte subsets including CD4/CD8 ratio where available; hsCRP; ferritin; 25-OH vitamin D; quantitative immunoglobulins (IgG, IgA, IgM, IgE) to rule out primary immunodeficiency, with IgG subclasses if infections are recurrent; an autoimmune screen (ANA, RF, anti-CCP, TPO and thyroglobulin antibodies); a thyroid panel; viral titres if chronic reactivation is suspected; and a Lyme and co-infection panel where exposure history warrants it.

Target ranges are deliberately not listed. The one exception worth naming is vitamin D, where the relevant point is not a target number but a mechanism: cathelicidin induction is vitamin D-dependent (PMID 16497887), so a documented deficiency should be corrected before an antimicrobial peptide protocol, at a level your clinician sets.

CIRS-specific labs

The Shoemaker panel — C4a, C3a, TGF-β1, MMP-9, VEGF, MSH, ADH/osmolality, anti-gliadin antibodies, MARCoNS culture, VCS testing — requires a provider trained in that framework. As noted above, this panel is specific to that framework rather than a validated diagnostic standard.

Follow-up

Repeat the abnormal baseline markers and inflammatory markers a few weeks after starting, reassess fully at around three months, and then periodically. See the Bloodwork Checklist.

Cycling Strategy

The cycling table previously here has been removed, because none of the schedules in it derive from a published human study of these compounds. What can be said:

• Thymosin α-1 was given as a defined short course in the sepsis trial, in an ICU, alongside conventional therapy (PMID 23327199). Long-term continuous use in outpatients has not been studied.
• LL-37 should not be used continuously, and the reason is mechanistic rather than a tolerance argument: it is an autoantigen in lupus and psoriasis (PMID 21389263), so cumulative exposure is the thing to minimize.
• Larazotide was given three times daily for 12 weeks in its trial, at the low dose (PMID 25683116) — one of the few schedules on this page that comes from a controlled trial.
• The Russian tradition uses short repeated courses. That is a tradition, not a validated schedule.

The general principle across the site applies here too: deliberate off periods exist so you can see your own baseline.

Frequently Asked Questions: Immune Peptides

Will immune peptides make me get sick less? Possibly, if your baseline immune function is genuinely impaired — and that is something labs can tell you. Thymosin alpha-1 has a double-blind placebo-controlled study showing augmented influenza antibody response in elderly men, and a multicentre randomized trial in severe sepsis that showed a mortality signal while missing its prespecified primary endpoint. Neither studied healthy adults hoping for fewer colds, and nothing here has been shown to improve immune function in someone whose immune system is already working.

Can I use thymosin alpha-1 if I have Hashimoto's? This needs provider judgment, and the honest answer is that nobody knows. Tα1's effect in established autoimmune disease has not been studied. The usual caution rests on an inference that it pushes Th1 immunity, while the primary mechanistic paper describes it as establishing a balance between inflammation and tolerance. Many integrative practitioners avoid it in active Hashimoto's; some use it with antibody monitoring. Do not self-decide.

Is LL-37 safe to take long-term? There is no long-term safety data for exogenous LL-37 and there is a specific mechanistic reason for concern: LL-37 acts as an autoantigen in lupus, where it complexes with self-DNA to activate plasmacytoid dendritic cells, and it appears among characterized psoriasis autoantigens. Most practitioners use short courses rather than continuous dosing, and anyone with autoimmune history or markers should not use it at all without specialist review.

What's the difference between Tα1 and the Russian thymic peptides? Tα1 has multicentre randomized trial data and pharmaceutical approval in a number of countries. Thymulin, thymogen and thymalin have no equivalent English-language randomized trials; what is well established for thymulin specifically is that its activity is zinc-dependent, which makes zinc status worth checking. They are not direct substitutes for Tα1.

Can immune peptides help with long COVID? The published Tα1 data is a retrospective review of 76 patients with acute severe COVID in hospital, not a long COVID trial — a different population entirely. Its mechanistic findings on T-cell exhaustion markers are interesting and relevant to the long COVID hypothesis, which makes this a research direction rather than an established treatment. Proper workup matters more than peptide choice.

Do I need to take vitamin D with LL-37? Vitamin D status matters for a specific reason: Toll-like receptor triggering induces cathelicidin through vitamin D receptor signalling, so endogenous LL-37 production depends on adequate vitamin D. Correcting a documented deficiency is upstream work that a clinician should set the target for, and it may reduce the rationale for exogenous LL-37 in the first place.

Can I use immune peptides during an active infection? Acute bacterial or severe viral infection needs conventional care first. Worth noting how the sepsis trial — which missed its prespecified primary endpoint — was designed: Tα1 was given in addition to conventional therapy in an intensive care unit, not instead of it (PMID 23327199). Adjunctive use under provider supervision is the only defensible framing.

How quickly do immune peptides work? There is very little trial data to answer this. In the sepsis trial, monocyte HLA-DR recovery was measurably better by day 3 and day 7, which shows the axis can move quickly in a critically ill population. For outpatient use, subjective reports of improvement over a few weeks are user reports rather than trial endpoints.

Is VIP something I can try on my own? No, and for two reasons. Within the Shoemaker framework it is the final step, and using it before the prerequisite steps are complete is reported to worsen inflammation. More broadly, no randomized controlled trial of intranasal VIP for CIRS could be located, and the marker panel that defines CIRS is not a validated diagnostic standard — so this is a clinical framework requiring a trained provider, not a protocol to run yourself.

Can I stack thymic peptides with antimicrobials like LL-37? It is a common combination for chronic biofilm-associated infection, and there is no trial of the combination. Given that LL-37 is an autoantigen in lupus and psoriasis and has no human efficacy trial, the autoimmune screen comes first and the risk-benefit conversation should be explicit rather than assumed.

Featured Protocols on Peptides.NYC

• Thymosin Alpha-1 Protocol — the one compound here with randomized trial data
• Thymulin, Thymogen & Thymalin Protocol — the Russian thymic class
• LL-37 Protocol — antimicrobial cathelicidin, with the autoantigen problem in full
• KPV Protocol — α-MSH-derived anti-inflammatory
• Defensins Protocol — mucosal antimicrobial peptides
• Splenopentin & Imunofan Protocol — the Russian immune class
• Immune Support Protocol — the multi-peptide framework
• VIP & CIRS Protocol — the Shoemaker framework and what supports it
• Larazotide Protocol — the gut-immune axis, with its inverted dose response

Related Content

• BPC-157 Complete Guide
• Bloodwork Checklist
• Doctor Conversation Script
• Peptide 101: What Are Peptides?
• Peptide Safety Guide
• Compounding Pharmacy Guide

Related Hubs

• Healing & Recovery Peptide Hub — BPC-157, KPV and the gut-repair overlap
• Longevity Peptide Hub — immunosenescence and the thymic bioregulators
• Cognitive Peptide Hub — post-viral cognitive symptoms
• Sleep Peptide Hub — sleep as immune infrastructure

Disclaimer: This content is for educational purposes only and is not medical advice. Immune peptides discussed in this hub are research compounds and most are not FDA-approved for human use in the United States. Thymosin alpha-1 (Zadaxin) is approved in a number of countries outside the US but not domestically.

Autoimmune Caveat — Read This Twice: Immune peptides are not generically safe. LL-37 is a documented autoantigen in lupus and psoriasis and should be avoided in anyone with autoimmune disease or markers. The thymic peptides have not been studied in established autoimmune disease at all, which is a reason for caution rather than reassurance. Anyone with Hashimoto's, rheumatoid arthritis, multiple sclerosis, lupus, psoriasis, type 1 diabetes, or a family history of autoimmunity should have a baseline autoimmune workup and provider consultation before starting any immune peptide. "Modulation" is not the same as "harmless."

Consult a qualified healthcare provider before starting any protocol. Self-experimentation with immune peptides is meaningfully riskier than with most other peptide categories.

Selected References

Every PMID linked above points to the PubMed record for that paper, so you can check the claim against the abstract yourself.

1. Wu J, Zhou L, Liu J, et al. The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial. Critical Care. 2013. PMID 23327199 · doi:10.1186/cc11932
2. Liu Y, Pan Y, Hu Z, et al. Thymosin alpha 1 reduces the mortality of severe coronavirus disease 2019 by restoration of lymphocytopenia and reversion of exhausted T cells. Clinical Infectious Diseases. 2020. PMID 32442287 · doi:10.1093/cid/ciaa630
3. Romani L, Bistoni F, Perruccio K, et al. Thymosin alpha1 activates dendritic cell tryptophan catabolism and establishes a regulatory environment for balance of inflammation and tolerance. Blood. 2006. PMID 16741252 · doi:10.1182/blood-2006-02-004762
4. Bozza S, Gaziano R, Bonifazi P, et al. Thymosin alpha1 activates the TLR9/MyD88/IRF7-dependent murine cytomegalovirus sensing for induction of anti-viral responses in vivo. International Immunology. 2007. PMID 17804687 · doi:10.1093/intimm/dxm097
5. Gravenstein S, Duthie EH, Miller BA, et al. Augmentation of influenza antibody response in elderly men by thymosin alpha one: a double-blind placebo-controlled clinical study. Journal of the American Geriatrics Society. 1989. PMID 2642497 · doi:10.1111/j.1532-5415.1989.tb01561.x
6. Ershler WB, Moore AL, Roessner K, et al. Interleukin-2 and aging: decreased interleukin-2 production in healthy older people does not correlate with reduced helper cell numbers or antibody response to influenza vaccine and is not corrected in vitro by thymosin alpha 1. Immunopharmacology. 1985. PMID 2932408 · doi:10.1016/0162-3109(85)90054-2
7. Ershler WB, Moore AL, Socinski MA. Influenza and aging: age-related changes and the effects of thymosin on the antibody response to influenza vaccine. Journal of Clinical Immunology. 1984. PMID 6334692 · doi:10.1007/BF00916574
8. Panatto D, Amicizia D, Lai PL, et al. Utility of thymosin alpha-1 (Zadaxin) as a co-adjuvant in influenza vaccines: a review. Journal of Preventive Medicine and Hygiene. 2011. PMID 22010537
9. Mao L. Thymosin alpha 1 — reimagine its broader applications in the immuno-oncology era. International Immunopharmacology. 2023. PMID 36871535 · doi:10.1016/j.intimp.2023.109952
10. Dardenne M, Savino W, Berrih S, et al. A zinc-dependent epitope on the molecule of thymulin, a thymic hormone. Proceedings of the National Academy of Sciences. 1985. PMID 2413455 · doi:10.1073/pnas.82.20.7035
11. Bach JF, Dardenne M. Thymulin, a zinc-dependent hormone. Medical Oncology and Tumor Pharmacotherapy. 1989. PMID 2657247 · doi:10.1007/BF02985220
12. Prasad AS, Meftah S, Abdallah J, et al. Serum thymulin in human zinc deficiency. Journal of Clinical Investigation. 1988. PMID 3262625 · doi:10.1172/JCI113717
13. Overhage J, Campisano A, Bains M, et al. Human host defense peptide LL-37 prevents bacterial biofilm formation. Infection and Immunity. 2008. PMID 18591225 · doi:10.1128/IAI.00318-08
14. Memariani H, Memariani M. Antibiofilm properties of cathelicidin LL-37: an in-depth review. World Journal of Microbiology and Biotechnology. 2023. PMID 36781570 · doi:10.1007/s11274-023-03545-z
15. Liu PT, Stenger S, Li H, et al. Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response. Science. 2006. PMID 16497887 · doi:10.1126/science.1123933
16. Lande R, Ganguly D, Facchinetti V, et al. Neutrophils activate plasmacytoid dendritic cells by releasing self-DNA-peptide complexes in systemic lupus erythematosus. Science Translational Medicine. 2011. PMID 21389263 · doi:10.1126/scitranslmed.3001180
17. Ten Bergen LL, Petrovic A, Aarebrot AK, et al. Current knowledge on autoantigens and autoantibodies in psoriasis. Scandinavian Journal of Immunology. 2020. PMID 32697368 · doi:10.1111/sji.12945
18. Pahar B, Madonna S, Das A, et al. Immunomodulatory role of the antimicrobial LL-37 peptide in autoimmune diseases and viral infections. Vaccines. 2020. PMID 32927756 · doi:10.3390/vaccines8030517
19. Chernomordik F, Cercek B, Lio WM, et al. The role of T cells reactive to the cathelicidin antimicrobial peptide LL-37 in acute coronary syndrome and plaque calcification. Frontiers in Immunology. 2020. PMID 33123157 · doi:10.3389/fimmu.2020.575577
20. Kannengiesser K, Maaser C, Heidemann J, et al. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflammatory Bowel Diseases. 2008. PMID 18092346 · doi:10.1002/ibd.20334
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Inclusion here is not endorsement — references 6 and 7 are listed because the thymosin vaccine-response record is mixed, and reference 27 because it is the negative permeability result for larazotide. Nothing on this page is medical advice.

Source: https://peptides.nyc/learn/goal/immune