Not sure where to start? Get matched →
Thymalin (Injectable)
Immune

Thymalin (Injectable)

Thymic peptide

All-in monthly price

$209

No membership fee · this is the full price · free shipping · avg 4-week supply

Medication, provider care, labs & dose adjustments — all in one price.
~28-day supply. Your provider sets your exact dose, so yours may vary — your refill arrives as you finish the last one.
Start assessment

Add in-depth bloodwork

Optional — add a physician-reviewed at-home blood panel to your plan.

At-home kit (1 device)+$149

Your sex-hormone baseline plus the safety markers that matter on therapy — blood counts, liver and kidney function — from one painless upper-arm device. Matched to your sex (PSA for men; progesterone & FSH for women). No needle, no clinic, physician-reviewed.

Money-back guarantee
Free AI care assistant
HSA/FSA accepted
Cancel anytime
Free shipping

This treatment requires licensed provider review and approval. Treatment is not guaranteed. If prescribed, medication is fulfilled by a licensed U.S. pharmacy where permitted by law. Compounded medications are not FDA-approved or FDA-cleared.

Dr. Gene
Physician Reviewed

Reviewed by Dr. Gene, MD · Board-certified Family Medicine

Every Pepti prescription is reviewed by a licensed U.S. physician before it's dispensed — and only provided if clinically appropriate.

About

Thymalin (Injectable)

Thymalin is a peptide taken from the thymus gland, the organ that trains the immune system's T-cells and shrinks with age. It is studied for restoring immune balance in older adults and for healthy aging. Compounded; not FDA-approved.

Benefits
Supports immune balance
Studied in older adults
Helps the body train its T-cells
Daily injection, Monday to Friday
Supply per fill
28-day

About a 4-week supply supply at the standard prescribed dose — your physician confirms exact dosing.

Physician review
24 hrs

A licensed US physician reviews your intake and prescribes when appropriate.

FDA-registered pharmacy
503A

Compounded fresh at a US pharmacy and shipped cold-chain to your door.

Shipping, always
Free

Every order ships free — medication, physician care and refills, one all-in price.

Formulation
Injectable vial5 mL · 1 mg/mL
Thymalin5 mg

Amounts shown are per unit. Compounded fresh at a US FDA-registered pharmacy.

Quality

Every batch independently tested

Every medication batch dispensed through Pepti is independently tested by a qualified third-party laboratory for applicable quality and safety standards before the pharmacy releases it. Batches are tested to the same standard used by 503B outsourcing facilities.

USP <71>
Sterility

Confirms the finished preparation is free of viable microorganisms.

USP <85>
Bacterial endotoxins

Screens for endotoxins that can cause fever or inflammatory reactions.

Assay
Potency

Verifies the labeled concentration of the active peptide is what is in the vial.

HPLC
Purity

Checks the active peptide against impurities and degradation products.

Mass spectrometry
Identity

Confirms the peptide in the vial is the correct molecule.

USP <791>
pH

Confirms the solution sits within the range specified for injection.

USP <788>
Particulate matter

Checks the finished vial for visible and sub-visible particles.

USP <1207>
Container closure integrity

Confirms the vial seal holds so sterility is maintained through the beyond-use date.

Recent lots
  • Lot 100526-THL-1

    Tested 2026-10-07 · Biolink Life Sciences Carolinas

    Sterility

    Sterile

    Endotoxin

    <2 EU/mL

    Potency

    99.3%

  • Lot 100526-THL-10

    Tested 2026-10-07 · Biolink Life Sciences Carolinas

    Sterility

    Sterile

    Endotoxin

    <2 EU/mL

    Potency

    99.2%

  • Lot 092826-THL-1

    Tested 2026-09-30 · Biolink Life Sciences Carolinas

    Sterility

    Sterile

    Endotoxin

    <2 EU/mL

    Potency

    99.2%

Compounded by licensed U.S. pharmacies. Prescribed by licensed medical providers. Shipped directly to patients.Documentation available upon request →View lab results by lot →
Your protocol

How Thymalin is prescribed.

Who it's for
  • Adults over 50 who get sick more often than they used to
  • People who want to support immune balance as part of a longevity protocol
  • Patients recovering slowly from illness whose physician is managing them
  • Anyone who prefers a natural thymus peptide over a synthetic immune drug

Your physician decides whether Thymalin is appropriate for you after reviewing your intake and labs.

Directions & duration

Inject 0.25 mL (25 units) subcutaneously once daily Monday through Friday.

Cycle. One small injection each day, Monday through Friday. Ongoing monthly treatment; your physician adjusts the dose as your goals evolve.
Directions shown are the pharmacy's standard for this preparation. Your prescription label is the final word.
What's included
  • Licensed physician review of your intake, history, and labs
  • Medication compounded to your prescription by a PCAB-accredited, FDA-registered pharmacy
  • Every batch independently tested before release
  • Sterile syringes and alcohol prep pads for injectables
  • Tracked delivery to your door, refills on schedule
  • Message your physician anytime; dose changes without an appointment
Storage & handling
  • Store refrigerated (36–46°F / 2–8°C) at all times, including before first use.
  • One vial is your monthly supply. A fresh vial ships every 28 days on your refill schedule, so you're always well inside the beyond-use date on your label.
  • Protect from light. Wipe the stopper with an alcohol pad before every draw.
  • Dispose of syringes in the sharps container per the included instructions.
What to expect

A typical course of Thymalin.

TimeframeWhat patients commonly report
Weeks 1–2Mild redness or a small bruise at the injection site is the most common early report.
Weeks 3–8Changes are gradual and build with continued use; most patients judge results at the two-month mark.
OngoingLong-term treatment. Refills ship every 28 days, and your physician adjusts the dose over time as your goals evolve.
Individual results vary. Compounded medications are not FDA-approved; a licensed physician determines whether treatment is appropriate and monitors your progress.
The full reference

Everything published
about Thymalin.

How it is described to work, pathway by pathway. What the research shows and what it does not. Where it stands with the FDA, dated and sourced.

Read the reference
7
References

peer-reviewed, each verified on PubMed

15
Sections

mechanism, evidence, dosing, safety, FAQ

Sep 24
FDA status verified

2026 · checked against fda.gov, not memory

The science

How Thymalin works, and what the research shows.

How it works

The thymus gland trains T-cells, the immune cells that recognize infections, and it shrinks steadily after our twenties.

Thymalin supplies the thymus's own peptides and is studied for restoring the signals that help T-cells mature and stay balanced.

Clinical evidence
  • A long-running Russian program reported fewer infections and better immune markers in older adults followed for years.

    Khavinson and Morozov, 2003
  • Western controlled trials have not been done.

Full references with PubMed links are listed further down the page.

References

  1. Khavinson VKh, Morozov VG. [Geroprotective effect of thymalin and epithalamin] · Adv Gerontol (2002) · PMID 12577695
  2. Khavinson VKh. Peptides and Ageing · Neuro Endocrinol Lett (2002) · PMID 12374906
  3. Khavinson VK, Linkova NS, Kvetnoy IM, Polyakova VO, Drobintseva AO, Kvetnaia TV, Ivko OM. Thymalin: Activation of Differentiation of Human Hematopoietic Stem Cells · Bull Exp Biol Med (2020) · PMID 33237528
  4. Khavinson VK, Kuznik BI, Trofimova SV, Volchkov VA, Rukavishnikova SA, Titova ON, Akhmedov TA, Trofimov AV, Potemkin VV, Magen E. Results and Prospects of Using Activator of Hematopoietic Stem Cell Differentiation in Complex Therapy for Patients with COVID-19 · Stem Cell Rev Rep (2021) · PMID 33575961
  5. Kuznik BI, Shapovalov KG, Smolyakov YN, Lukyanov SA, Tereshkov PP, Kazantseva LS, Linkova NS. [Morphological compound and indicators of the blood clotting system in severe COVID-19 patients of middle aged and elderly during treatment of Tocilizumab and Thymalin] · Adv Gerontol (2022) · PMID 36169363
  6. Avolio F, Martinotti S, Khavinson VK, Esposito JE, Giambuzzi G, Marino A, Mironova E, Pulcini R, Robuffo I, Bologna G, Simeone P, Lanuti P, Guarnieri S, Trofimova S, Procopio AD, Toniato E. Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line · Int J Mol Sci (2022) · PMID 35408963
  7. Linkova N, Khavinson V, Diatlova A, Petukhov M, Vladimirova E, Sukhareva M, Ilina A. The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19 · Int J Mol Sci (2023) · PMID 37686182

Citations are provided for educational purposes. They do not constitute medical advice. Always discuss any peptide protocol with your prescribing physician.

Important safety information

+

Possible side effects

• Mild redness or swelling at injection site
• Temporary fatigue or headache
• Mild nausea (uncommon)

Do not use if you have

• Active cancer or history of cancer (unless approved by oncologist)
• Pregnancy or breastfeeding
• Severe kidney or liver disease
• Known allergy to the peptide or excipients

If you experience severe side effects, call 911 or go to your nearest emergency room.

How supplied

vial — Thymalin 5mg/5mL 1mg/mL (5mL)

Common questions

Frequently asked
about Thymalin (Injectable).

Thymalin is a peptide taken from the thymus gland, the organ that trains the immune system's T-cells and shrinks with age. It is studied for restoring immune balance in older adults and for healthy aging. Compounded; not FDA-approved. Thymalin is prescription-only at Pepti: a licensed physician reviews your assessment and, if appropriate, prescribes it to be compounded by a state-licensed, FDA-registered pharmacy.

33 more questions about Pepti, answered.

One vial is your monthly supply at the dose your physician prescribes. A fresh vial ships about every 28 days, and the date moves if your physician changes your dose. Store it as the pharmacy label directs, refrigerated.

Get started today

Ready to start with Thymalin (Injectable)?

Free assessment. Licensed physicians. Money-back guarantee if not approved.

Money-back guarantee
Free shipping
Cancel anytime
HSA/FSA accepted
Start free assessment
Total care.
In your pocket.

Message your medical team, track every order, chart every lab marker. 5.0 on the App Store.

Get the app
A hand holding an iPhone showing the Pepti app
Pharmacy network accreditation

PCAB-accredited pharmacies on every order.

Every fulfillment runs through a PCAB-accredited pharmacy.

See the lab results
PCAB — Pharmacy Compounding Accreditation Board · Accredited
  • Rigorous third-party quality & safety inspections
  • Cleanliness and sterile processes
  • Proper ingredient sourcing
  • Accurate dosing and formulation
  • Staff training and procedures
  • Accredited by NABP & ACHC