Peptides  /  Thymosin Alpha-1
For Adults · Compounded Peptide

Thymosin Alpha-1

An immune-signalling peptide.

A 28-amino-acid peptide derived from thymosin fraction 5, studied in immune modulation and approved as a medicine in a number of countries outside the United States. Prescribed after a licensed provider reviews your online visit.

$299

Start your online visit →

A few private questions, then a licensed provider reviews your answers.

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ForbiddenRx Thymosin Alpha-1 vial
At a glance
Form
Injection
Cadence
Set by your provider
Class
28-amino-acid peptide
Guided by
Provider review
Helps with
Immune category
For
Adults 18+
The basics

What is Thymosin Alpha-1?

What it is
28-amino-acid peptide
Forms
Injection
Supplied as
5mg
Dosing
Set by your prescriber
Supply
1-month or 3-month
Visit
Online, reviewed by a licensed provider
Prescription
Provider-reviewed · not available OTC
Shipping
Discreet, unmarked · most U.S. states
Start your online visit →

Thymosin alpha-1 is a 28-amino-acid peptide originally isolated from thymosin fraction 5, a thymic extract. It has been studied extensively in immune modulation, particularly in chronic hepatitis B and C and as a vaccine adjuvant.

Thymalfasin, the synthetic form, is approved as a medicine in a number of countries outside the United States. It is not FDA-approved in the U.S., and what is dispensed here is a compounded preparation.

This is a compounded preparation, not an FDA-approved medication, and compounded drugs are not reviewed by the FDA for safety or effectiveness. Individual results are not guaranteed. It is prescribed only where a licensed provider determines it is appropriate after reviewing your health history.

Why people ask about it

Why does Thymosin Alpha-1 come up?

Thymosin alpha-1 has a larger clinical literature than most peptides in this catalogue, including controlled trials in chronic viral hepatitis, and is an approved medicine in several countries. It is not approved in the United States, and a compounded preparation is not a substitute for treatment of any diagnosed infection.

✔A provider decides, not a quiz

Every Thymosin Alpha-1 prescription here follows a review by a licensed provider of your health history, current medications and goals. If it isn't appropriate for you, it isn't prescribed.

✔Compounded, not a research chemical

Your vial is compounded by a licensed U.S. 503A pharmacy and dispensed against a prescription written in your name — not sold as a "research only" product with no oversight.

Know the difference

Prescribed Thymosin Alpha-1 vs. supplements and grey-market vials — what's the difference?

The short answer: unregulated supplements make claims nobody checks, "research only" vials sold online carry no prescription, no pharmacy and no accountability, and a prescribed Thymosin Alpha-1 is compounded by a licensed 503A pharmacy against a provider's order written for you.

 Oral supplement"Research only" vialPrescribed Thymosin Alpha-1 (Rx)
What it isAn unregulated oral precursorA vial sold without a prescriptionCompounded Thymosin Alpha-1 dispensed on a provider's order
Licensed provider reviews youNoNoYes — before anything is dispensed
Compounded by a licensed pharmacyNoNoYes — U.S. 503A
Your name on the vialNoNoYes
Dose set by a prescriberNoNoYes
Legal to sell for human useAs a supplementNoYes — by prescription

The simplest test of any peptide seller: is your name on the vial? A "research only" label means no prescriber reviewed you, no licensed pharmacy compounded it, and nobody is accountable for what is actually inside.

How it works

How does getting Thymosin Alpha-1 actually work?

Three steps: answer a short set of medical questions, a licensed provider reviews them, and if they prescribe, a 503A pharmacy compounds and ships it.

I

Answer a few questions

A short private medical questionnaire — your history, current medications and what you are hoping to address. It takes a couple of minutes.

II

Meet your provider live

A provider licensed in your state reviews your answers online — no appointment, no waiting room. They decide whether Thymosin Alpha-1 is appropriate.

III

Compounded & shipped

If they prescribe, a licensed U.S. 503A pharmacy compounds your vial and ships it discreetly, with your name on the label.

Who it's for

Who is Thymosin Alpha-1 for?

It's for adults who want Thymosin Alpha-1 prescribed and compounded properly rather than bought from a grey market. Whether it is appropriate for you is a decision for the provider who reviews your visit.

✔Interested in immune support

Thymosin alpha-1 has been studied in immune modulation and as a vaccine adjuvant.

✔You want a real prescription

Reviewed by a licensed provider, compounded by a 503A pharmacy, dispensed with your name on the vial.

✔You want the dosing decided for you

Amount and schedule are set by your prescriber.

✔You prefer an injectable

Thymosin alpha-1 is compounded as a subcutaneous injection.

✕When it's not the right fit

Thymosin alpha-1 is not FDA-approved in the United States and is not a treatment for any infection, including hepatitis. Anyone with an autoimmune condition or taking immunosuppressive therapy should tell their provider before starting. Compounded drugs are not FDA-reviewed for safety or effectiveness. If you are pregnant or breastfeeding, have an active cancer diagnosis, or have significant kidney or liver disease, tell your provider in your answers. New or unexplained symptoms should be evaluated by a clinician rather than self-treated.

How to get it

How do I get Thymosin Alpha-1 online?

You answer a few questions, a licensed provider reviews your answers, and — if they prescribe — your medication is compounded and shipped to your door. No insurance required, no in-person appointment, no waiting room.

A few questions

Answer a short set of private medical questions. Add as many peptides as you like; one checkout, and a provider reviews each.

Online provider review

A provider licensed in your state reviews your answers online. Approval is never guaranteed.

Discreet delivery

If prescribed, your vial is compounded by a 503A pharmacy and ships in plain, unmarked packaging to most U.S. states.

Pricing is shown at checkout — no insurance needed, no hidden fees.

Using it & safety

How is it taken, and is it safe?

Thymosin Alpha-1 is compounded as injection. The amount and the schedule are set by the provider who reviews your visit — we deliberately do not publish a dosing regimen here, because that is a clinical decision about you, not a product specification.

Forms & how it's taken

Injection
Compounded as injection.
Supplied as
5mg. Which one you receive is part of the prescription.
Dose & schedule
Set by your prescriber. Follow the directions on your label.
Supply
1-month or 3-month. Three months costs less per month.
Injection5mgProvider-set

Safety & side effects

⚠ Not a treatment for infection

Thymosin alpha-1 is not FDA-approved in the United States and is not a treatment for any infection, including hepatitis. Anyone with an autoimmune condition or taking immunosuppressive therapy should tell their provider before starting. Compounded drugs are not FDA-reviewed for safety or effectiveness.

Reported effects are most often related to the injection itself or to infusing too quickly. They can include:

  • Redness or discomfort at the injection site
  • Transient fatigue
  • Joint or muscle aches
  • Low-grade fever

Tell your provider about every condition and medication before starting, including pregnancy or breastfeeding. Stop and seek care for signs of an allergic reaction — rash, swelling of the face or throat, or difficulty breathing. For emergencies call 911.

Compare your options

Which skin and repair peptide fits you?

A side-by-side look at the skin & repair options available through ForbiddenRx. Which one is appropriate for you is decided by the provider who reviews your visit.

TreatmentWhat it isFocusFormForRx required
Thymosin Alpha-1
This page		28-amino-acid peptideImmune categoryInjectionAdults 18+Yes
GHK-CuCopper tripeptideSkin & repair categoryInjection · CreamAdults 18+Yes
EpithalonSynthetic tetrapeptideLongevity categoryInjectionAdults 18+Yes
MOTS-cMitochondrial-derived peptideMetabolic categoryInjectionAdults 18+Yes
Questions, answered

Thymosin Alpha-1 FAQ

What is thymosin alpha-1?

A 28-amino-acid peptide originally isolated from a thymic extract, studied in immune modulation — particularly in chronic hepatitis B and C and as a vaccine adjuvant.

Is it approved anywhere?

Thymalfasin, the synthetic form, is approved as a medicine in a number of countries outside the United States. It is not FDA-approved in the U.S., and the preparation dispensed here is compounded.

Can it treat an infection I already have?

No. It is not a treatment for any infection. If you have or suspect one, that needs proper medical evaluation.

Do I have to book an appointment?

No. You complete the questionnaire online and a licensed provider reviews it — there is no scheduling step and no waiting room.

Can I order more than one peptide?

Yes. Add each one to your cart and check out once. A provider reviews every treatment in your order.

Credibility you can verify

Care held to a higher standard

Licensed Providers

U.S. board-certified clinicians

503A Pharmacies

U.S.-based compounding partners

Most U.S. States

We confirm your state during intake

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Epithalon

A telomere-associated peptide.

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Category

The Peptide Catalog

Every peptide we can dispense, each prescribed by a licensed provider and compounded by a 503A pharmacy.

Learn more →

Start with a real prescription

If you are going to take Thymosin Alpha-1, take one a licensed provider prescribed and a 503A pharmacy compounded with your name on it. Answer a few questions and a licensed provider reviews them.

Start your online visit →

  • Discreet, unmarked packaging
  • Refills so you never miss a dose
  • Labs guiding every adjustment
  • Licensed providers in most U.S. states
Medically reviewed

Sources & references

Medically reviewed by ForbiddenRx Medical Affairs — Independent, licensed medical providers · Last reviewed August 2026. This page was written and is periodically reviewed for medical accuracy in line with clinical guidance followed by the independent, licensed medical providers in the ForbiddenRx network. It is provided for general educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk with a licensed provider about your individual health.

  1. Chien RN et al. Efficacy of thymosin alpha-1 in patients with chronic hepatitis B: a randomized controlled trial. Hepatology.
  2. Garaci E et al. Thymosin alpha-1: from bench to bedside. Annals of the New York Academy of Sciences.
  3. U.S. Food & Drug Administration. Compounding and the FDA: questions and answers — the regulatory basis for how this preparation is dispensed.
For further reading

Clinical references

This page is educational and is not medical advice.