Immune
Immune Stack
Thymosin alpha-1 plus KPV. A clinic offering, and the most-cited immune pairing in circulation. One half has real trial data; the other half has none at all.
At a glance
- Sold as
- Separate vials
- The evidence
- Thymosin alpha-1 alone has genuine trial data, including positive results in chronic hepatitis B and a 1,089-patient Phase 3 in sepsis that was negative. The combination has none. KPV has no human data of any kind by FDA's own search. Note also that thymosin alpha-1 has no US marketing authorisation, and a DailyMed search for thymalfasin returns nothing, so "prescription" does not mean obtainable here.Combination-specific research is limited. Treat each compound’s evidence as separate unless a study of the combination itself is named here, and review the complete plan with a qualified clinician.
Running this stack, with the schedule, the vials it takes and a log of what you took, happens in the app: Claritide for iPhone.
Why people explore it
Common reasons for exploring it
- People working with a clinic that already offers this pairing and want to understand what the evidence actually is
- Anyone comparing the trial schedule against the protocol they were handed
Where clinician input matters
- Organ transplant recipients and anyone on immunosuppressants
- Anyone in an active autoimmune flare
- Pregnant or nursing, under 18
- Anyone expecting an FDA-approved product at the end of it
The science
Read the compound mechanisms
Thymosin alpha-1 is an immunomodulator rather than an immune stimulant, and the distinction matters. It promotes maturation of T cells, activates natural killer cells and dendritic cells, and restores HLA-DR expression on monocytes, a marker that falls in severe illness and is used as a readout of immune paralysis. In sepsis studies it improves the ratio of CD4-positive to CD8-positive T cells. The through-line is that it pushes an under-responding immune system back toward a normal configuration, which is why the trials that exist are in conditions of immune exhaustion rather than in healthy adults.
The story you will read everywhere is that KPV is a melanocortin receptor agonist, and FDA says that is probably wrong. In its 2026 briefing document FDA writes that several lines of evidence suggest melanocortin receptors are unlikely to be the molecular targets behind KPV, because KPV could not displace radiolabelled alpha-MSH binding in rat brain tissue, in murine melanoma cells or in MC1R-expressing macrophages, and did not raise cAMP in those macrophages. What FDA does consider plausible is inhibition of NF-κB, the master switch that turns on pro-inflammatory cytokine genes, plus inhibition of interleukin-1β effects. The third piece is transport: KPV is taken up into human intestinal epithelial cells and Jurkat T cells through PepT1, a peptide transporter that is upregulated in inflamed gut tissue. That last detail is the one that makes the gut argument mechanically coherent: the transporter that carries it in is more abundant exactly where the inflammation is.
Commonly researched ranges
- Thymosin alpha-11.6 mg
- KPV100–500 mcg
| Compound | Amount | Frequency | Timing |
|---|---|---|---|
| Thymosin alpha-1 | 1.6 mg | Twice weekly, 3–4 days apart | Subcutaneous |
| KPV | 100–500 mcg | Once daily subcutaneously; 200–500 mcg one to two times daily orally | Empty stomach reported for the oral route |
- Thymosin alpha-1: This is the Phase 3 chronic hepatitis B schedule (Chien 1998), not a vendor protocol. The daily community protocol that circulates rests on a vendor-blog figure and is not reproduced here. Reported reconstitution: a 10 mg vial plus 2 mL bacteriostatic water gives 5 mg/mL, so 1.6 mg is 0.32 mL, 32 units on a U-100 syringe.
- KPV: Vendor-tier community practice with zero human-trial support.
- Duration
- The hepatitis B trial schedule ran 26 weeks. Community immune use is shorter and undefined. No source defines a duration for the combination.
Mixing each compound
Not established in available literature. Use the figures printed on your own vial.
What it costs
Not established in available literature for any compound in this stack. Claritide’s cost engine will track what you actually pay once you log a vial.
Cautions
- Some clinics list a three-compound version adding LL-37. We carry it as a variant rather than a default member, and the reason is FDA's own note on cathelicidin LL-37: "Nonclinical research findings suggest detrimental effects on male reproduction and that this drug can be protumorigenic in some tissues." There is also no validated human injection dose for LL-37. The one real trial was topical, in venous leg ulcers, and showed no significant difference in the total study group.
- The 20-day thymulin priming cycle that circulates ahead of this stack comes from a single source that flagged itself as unverified. It is not reproduced here.
- Thymosin alpha-1 activates the immune system. That directly opposes anti-rejection therapy. Organ transplant recipients on immunosuppressants, and anyone in an active autoimmune flare, are the exclusions that matter.
- A transient ALT flare is documented during hepatitis B therapy with thymosin alpha-1.
- There is no US prescription product for thymosin alpha-1. Orphan-drug designation is not approval, and a DailyMed search returns no marketed label.
- Widely repeated figures trace to vendor blogs and aggregators: "4,400+ published articles", "prescribed in 35+ countries", ">11,000 subjects across 30+ trials". We do not publish them as fact.
- KPV is not named on WADA's list. We found no approval for KPV, so athletes should treat it as likely prohibited under S0. Thymosin alpha-1's WADA status is genuinely undetermined, and we will not call it banned.
Absence from this list does NOT mean safety. It means lack of research.
Every stack here is free to read, and it stays free. Your own schedule, vials and log live in the app: Claritide for iPhone.