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№ 029

Thymosin Alpha-1 (Tα1)

Immune-system peptide. Approved in many countries for hepatitis B/C and as adjunct to chemotherapy. Used here for chronic immune issues and post-illness recovery.

Immune
Evidence: Moderate

Thymosin Alpha-1 (Tα1): Immune-system peptide. Approved in many countries for hepatitis B/C and as adjunct to chemotherapy. Used here for chronic immune issues and post-illness recovery. Thymosin Alpha-1 is the immune-system peptide.

FDA ⓘ
Not approved
WADA
Not banned
Typical dose
1.6 mg sub-q
Half-life ⓘ
~2 hours
Route ⓘ
Subcutaneous
Schedule
1-2x weekly
In plain English

Thymosin Alpha-1 is the immune-system peptide. Approved in many countries for hepatitis and as adjunct to chemotherapy. Used here for chronic immune issues, post-illness recovery, or as a winter immune-support tool.

Status & legalityWhat do these mean? →
Natty? ⓘ
Not natty
FDA ⓘ
Not approved

Not FDA approved in the U.S. Has orphan drug status for some indications. Approved in 35+ countries (sold as Zadaxin) for hepatitis B/C and chemotherapy adjunct.

Compounding ⓘ
Category 1

Compounding pharmacies may prepare under physician prescription (post Feb 2026 reclassification, pending formal FDA publication).

WADA ⓘ
Not listed

Interpretation varies, falls outside explicit S2 listing.

Prescribed ⓘ

Yes outside the U.S., prescribed by hepatology / oncology providers in countries where Zadaxin is approved.

Who it's for

  • →Users with chronic immune issues
  • →Post-illness recovery support
  • →Cancer / hepatitis-adjunct context under medical care

What to expect

  1. Week 1

    Subtle. Energy / immune-feel often shifts first.

  2. Week 4

    Chronic-illness markers improve in clinical contexts.

  3. Week 8

    Plateau. Cycle off.

Looking at Thymosin Alpha-1 (Tα1)? Your next 3 steps

  1. 1Work out your exact dose

    Vial size + BAC water turns into the exact units to draw for Thymosin Alpha-1 (Tα1).

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  2. 2See what to stack & monitor

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How it works (mechanism)

28-amino-acid peptide derived from prothymosin alpha. Activates Toll-like receptors (both TLR2 and TLR9) on dendritic cells, broadly enhancing T-cell-mediated immune responses without direct antigen specificity.

Dosing protocol

Members only

Stacks well with

Members only

Side effects

01Generally well tolerated
02Mild injection-site irritation

When NOT to use

  • ⚠Active immunosuppression therapy (talk to provider)
  • ⚠Pregnancy / nursing

Bloodwork to monitor

  • • CBC if running long term

Common mistakes

  • • Treating it like an acute immune fix
  • • Skipping cycle breaks
  • • Underdosing for chronic conditions

Drug & supplement interactions

  • ⚠Immunosuppressants (cyclosporine, tacrolimus, biologics): may counteract Tα1's immune-enhancing effect
  • ⚠Vaccination: may enhance vaccine response
  • ⚠Limited published interaction data outside oncology / hepatitis contexts

Community patterns

Members only
Free, no account needed

New to Thymosin Alpha-1 (Tα1)? Grab the starter checklist.

Drop your email and we'll send the one-page first-cycle starter checklist, plus a heads-up if Thymosin Alpha-1 (Tα1) changes legal status. No account needed.

No spam. No selling your email. Just the checklist and the occasional reclassification alert.

AI Coach, live sample
Members only
is 250mcg of bpc enough for a knee injury?
For a knee, 250 mcg sub-q daily is the standard working dose and a solid place to start. The trick with BPC is consistency, give it weeks, not days. Inject close to the joint, run it 4-6 weeks, and don't drop below 200 mcg, it tends to stop cracking the threshold reliably down there. If it hasn't moved at all by week 3, that's when adding TB-500 earns its place.
how much bac water for a 10mg reta vial?
3 mL is the standard play for a 10 mg reta vial. That's 3,333 mcg/mL, clean unit math across the titration: 2 mg = 60 units, 4 mg = 120 units, 6 mg = 180 units on a 100-unit insulin syringe. Run 2 mL instead if you want fewer, more concentrated shots (5,000 mcg/mL, so 2 mg = 40 units). Since most people titrate up over ~12 weeks, 3 mL keeps the numbers cleanest.
what should i track on bloodwork for tirzepatide?
Lipid panel, ALT/AST (liver enzymes), and an A1C, baseline before you start then every 3 months. If you've got metabolic-syndrome history, add fasting glucose and insulin so you can actually watch insulin sensitivity improve. You don't need a big hormone panel for a GLP-1.

Ask the Coach anything about Thymosin Alpha-1 (Tα1) or your own stack. This is it working.

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Frequently asked

What is Thymosin Alpha-1 (Tα1)?+
Thymosin Alpha-1 is the immune-system peptide. Approved in many countries for hepatitis and as adjunct to chemotherapy. Used here for chronic immune issues, post-illness recovery, or as a winter immune-support tool.
Is Thymosin Alpha-1 (Tα1) FDA approved?+
Not FDA approved in the U.S. Has orphan drug status for some indications. Approved in 35+ countries (sold as Zadaxin) for hepatitis B/C and chemotherapy adjunct.
Is Thymosin Alpha-1 (Tα1) legal?+
Thymosin Alpha-1 (Tα1) is not FDA-approved. It is sold by compounding pharmacies (with a prescription) and as "research only" by peptide vendors. Possession is generally not criminalized but distribution without authorization may be. Verify local laws.
Is Thymosin Alpha-1 (Tα1) banned by WADA?+
Thymosin Alpha-1 (Tα1) is not currently on the WADA prohibited list. Interpretation varies, falls outside explicit S2 listing.
Are you still natty after taking Thymosin Alpha-1 (Tα1)?+
No. Thymosin Alpha-1 (Tα1) is a performance-enhancing peptide and would disqualify a strict natty claim.
Do doctors prescribe Thymosin Alpha-1 (Tα1)?+
Yes outside the U.S., prescribed by hepatology / oncology providers in countries where Zadaxin is approved.
What's the typical dose of Thymosin Alpha-1 (Tα1)?+
1.6 mg sub-q, twice weekly. In clinical settings, dosing is condition-specific.
What are the side effects of Thymosin Alpha-1 (Tα1)?+
Common side effects include: Generally well tolerated; Mild injection-site irritation. Less common effects and full safety details are on the entry page.
How long until Thymosin Alpha-1 (Tα1) starts working?+
Subtle. Energy / immune-feel often shifts first.
What can you stack with Thymosin Alpha-1 (Tα1)?+
Common pairings: BPC-157 for gut + immune protocols; Standalone. Full stacking protocol and timing on the entry page.
Where do people get Thymosin Alpha-1 (Tα1)?+
Thymosin Alpha-1 (Tα1) is most commonly sold by research-only peptide vendors and by compounding pharmacies (the latter requires a prescription). Pepdex is not a vendor, see /coa for how to verify a Certificate of Analysis before buying from any source, and /guides/scam-vendor-spotting for vendor red flags.
Thymosin Alpha-1 (Tα1) vs LL-37, which is better?+
Thymosin Alpha-1 vs LL-37: immune modulator vs direct antimicrobial peptide. Different jobs in the same system. Full head-to-head comparison: https://pepdex.co/compare/thymosin-alpha-1-vs-ll-37

Head-to-head with Thymosin Alpha-1 (Tα1)

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Thymosin Alpha-1 (Tα1) vs LL-37 →

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