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Thymosin Alpha-1

A thymic peptide that modulates dendritic cell and T-cell function for balanced immune enhancement.

Dr. Jonathan Snipes, MDMedically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.
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Thymosin Alpha-1 dispensed by a licensed U.S. 503A compounding pharmacy

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Immune EnhancementT-Cell SupportClinically ProvenBalanced Modulation

What It Is

Thymosin Alpha-1 is a peptide naturally produced by the thymus gland. It's been approved in over 35 countries for immune modulation and has extensive clinical data.

How It Works

It enhances the function of dendritic cells and T-cells, helping your immune system better identify and respond to threats while maintaining balanced immune regulation.

Who It's For

Those looking to optimize immune function, recovering from chronic infections, or seeking immune support during recovery protocols.

Who Should Avoid It

Flag if on immunosuppressants. Not for organ transplant recipients without careful monitoring.

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A licensed provider reviews every order.

Protocol & Pricing

Pharmacy Price

$80

3mg/mL, 5mL vial (15mg total)

You pay pharmacy price. No markup.

Starting Dose

53 units (1.6mg)

Form

Injectable vial, 5mL

Your pharmacy label will read

THYMOSIN ALPHA-1

3 MG/ML (5 ML)

The label shows strength per mL, not the total in the vial.

What that means

  • 3mg/mL means 3mg in every mL.
  • The vial holds 5mL, so 3mg/mL × 5mL = 15mg in the vial.
  • Each 53-unit injection (0.53mL) gives you 1.59mg, about 9 injections per vial.

Dosing Protocol

53 units subcutaneous injection twice weekly, on the same two days each week (for example Monday and Thursday). 53 units = 0.53mL × 3mg/mL = 1.6mg per injection. This is a larger draw than most products, more than half a syringe, so read the barrel carefully.

Beyond Use Date

90 Days from compounding (USP <797>)

A licensed U.S. 503A compounding pharmacy assigns this date and prints it on your vial label. Always follow the label.

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Why this dose, and what the evidence shows

From our medical director's protocol for Thymosin Alpha-1. Where the evidence is thin, it says so.

Why this dose

Thymosin alpha-1, also known as thymalfasin, has decades of international clinical use.

A common studied regimen is 1.6 mg injected under the skin twice weekly. This protocol follows that established clinical dosing pattern.

Consistent dosing matters because the immune effects studied with thymosin alpha-1 develop over repeated treatment rather than from a single injection.

What the evidence shows

Thymosin alpha-1 has one of the larger human research records among the compounds offered in this program.

Randomized trials and other clinical studies have evaluated thymosin alpha-1 in chronic viral hepatitis, cancer-related immune dysfunction, serious infections, and critical illness.

Results differ by condition and patient population.

Use for general immune support, recurrent minor illness, or post-viral fatigue in otherwise healthy adults has not been established through the same level of clinical research.

Thymosin alpha-1 is not FDA approved in the United States. The compounded product used in this program is prescribed based on clinician judgment.

Each order also carries the $39 prescriber review. Pharmacy prices are the pharmacy's own; we add nothing to them.

Ready to add Thymosin Alpha-1?

A licensed provider reviews every order.

Stacking Guide

Stacks Well With

BPC-157NAD+ Injectable

Ready to add Thymosin Alpha-1?

A licensed provider reviews every order.

Thymic immune peptide

Read the Thymosin Alpha-1 protocol guide

The 2025 TESTS sepsis trial failed. The hepatitis B evidence stays strong. ME/CFS, Long Lyme, Long COVID applications are mechanistically plausible. 20 to 30 percent non-responder rate.

Read guide

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A 15-amino acid peptide prescribed as an injection under the skin. Studied for tissue repair, mostly in animals.

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The cellular energy molecule. Injectable NAD+ for direct bioavailability and cellular rejuvenation.

$100 · 100mg/mL, 10mL vial (1000mg total)

BPC-157/KPV Capsules

Oral BPC-157 paired with KPV. Gut-targeted tissue repair plus anti-inflammatory action in a single daily capsule.

$4.50/cap

KPV Capsules

Oral KPV on its own. The alpha-MSH tripeptide in a 500mcg capsule, with no BPC-157 or TB-500 alongside it.

$2.25/cap

Independently tested

Thymosin Alpha-1 certificate of analysis

All 5 Thymosin Alpha-1 samples tested for sterility and endotoxin passed both. Latest sample received by the lab Sep 25, 2026.

Every Thymosin Alpha-1 batch dispensed by a licensed U.S. 503A compounding pharmacy is independently tested by Eagle Analytical Services (FDA-registered, A2LA ISO 17025 accredited). Sterility testing checks that nothing grows in the sample; the USP <85> endotoxin test checks for bacterial toxins that can cause fever. Below is the lab's own report for each of the 5 most recent lots.

Lot LG342010886, received Sep 25, 2026

Sterility
PassScanRDI Sterility Test. Started Sep 25, 2026, completed Sep 30, 2026. Method suitability ETX-260604-0235
Bacterial endotoxin
PassUSP <85>. Measured <2 EU/mL, limit 1750 EU/mL. Started Sep 28, 2026, completed Sep 28, 2026
Sample, as printed
Thymosin Alpha-1 3mg/ml (5ml)
Lot #
LG342010886
Storage
Refrigerated
Received by lab
Sep 25, 2026
Laboratory
Eagle Analytical Services Inc., Houston, TX
Submission #
ETX-260925-0586
Signed
Alison Eng, Quality Control Manager
Scan of Eagle Analytical report ETX-260925-0586 for lot LG342010886. Opens the original PDF.
Eagle Analytical report ETX-260925-0586. Open the original PDF (opens in a new tab)

Eagle Analytical Services is an independent FDA-registered laboratory, A2LA accredited to ISO 17025, based in Houston, Texas. They have no commercial relationship with Rx Peps Direct. Rx Peps Direct prescribes; the pharmacy compounds and dispenses; Eagle tests every batch. Three separate companies. Results apply only to the tested sample as received. Browse our full quality program on the quality page.

Ready to add Thymosin Alpha-1?

A licensed provider reviews every order.

How to get Thymosin Alpha-1 prescribed online

Thymosin Alpha-1 is available by prescription after an online medical review and dispensed for human use by a licensed 503A pharmacy. That is what separates it from research-use-only vials sold without a prescription. There is no membership, just a medical review fee per order, and automatic refills are optional.

  1. 1

    Complete a $39 medical review. Answer a short intake about your health history and your goals for Thymosin Alpha-1. The $39 fee is the only charge Rx Peps Direct collects, paid once, not a recurring subscription.

  2. 2

    A licensed provider reviews it. A US-licensed clinician reviews your intake and, if Thymosin Alpha-1 is appropriate for you, writes a patient-specific prescription. The starting dose is typically 53 units (1.6mg).

  3. 3

    The pharmacy compounds and ships it. A licensed 503A compounding pharmacy in Texas compounds Thymosin Alpha-1 and ships it pre-reconstituted by FedEx overnight in a reusable cooled case. Your fill is a 5mL injectable vial at 3mg/mL (15mg total), labeled "THYMOSIN ALPHA-1 3 MG/ML (5 ML)", and you pay the pharmacy $80 per vial at wholesale, with no clinic markup, plus a $15 flat FedEx overnight shipping fee charged by the pharmacy.

Rx Peps Direct prescribes Thymosin Alpha-1 in the 28 states plus Washington, DC where its medical team is licensed. Start your $39 medical review or browse the full Recovery & Repair range. Comparing services first? See how Rx Peps Direct stacks up against seven other providers in our best telehealth for compounded peptides comparison.

Ready to add Thymosin Alpha-1?

A licensed provider reviews every order.

Common questions about Thymosin Alpha-1

What is thymosin alpha-1?
Thymosin alpha-1 is a 28-amino acid peptide originally isolated from thymus gland extract. It modulates innate and adaptive immunity by activating dendritic cells and enhancing T-cell function. The molecule is approved as a hepatitis B treatment in many countries outside the United States (under the brand name Zadaxin) and is used investigationally in the U.S. for immune support during viral illness, post-COVID recovery, and chronic infection protocols.
Does thymosin alpha-1 work for immune support?
Thymosin alpha-1 has the strongest evidence base of any compounded immune peptide. It is approved internationally for chronic hepatitis B and is used adjunctively in cancer-related immunosuppression. Smaller studies and observational data support its use in post-viral recovery and stubborn-infection protocols. Effects are gradual; most protocols run at least 4 weeks before assessment.
How is thymosin alpha-1 dosed when sick?
The Rx Peps Direct dose is 53 units (1.6 mg) on a U-100 insulin syringe, injected subcutaneously twice weekly on the same two days each week (for example Monday and Thursday). At the 3 mg/mL concentration, 53 units is 0.53 mL, more than half a syringe, so read the barrel carefully. A licensed U.S. 503A compounding pharmacy compounds thymosin alpha-1 against Rx Peps Direct prescriptions; your provider confirms the protocol at review.
Where do I inject thymosin alpha-1?
Subcutaneously into the abdomen, upper outer thigh, or back of the upper arm using a 31-gauge, 5/16-inch (8 mm) needle on a U-100 insulin syringe. Sterile syringes are included with every Rx Peps Direct shipment.
How is thymosin alpha-1 supplied?
Compounded by a licensed U.S. 503A compounding pharmacy under a patient-specific prescription. Ships pre-reconstituted and ready to inject in cold-chain packaging. Every batch is tested by Eagle Analytical Services; the Certificate of Analysis is published on this product page.

Ready to add Thymosin Alpha-1?

A licensed provider reviews every order.