Thymulin (FTS) vs Thymalin — Peptide Comparison

At a Glance

Quickcomparison

Dose Range

Thymulin (FTS)

100–500 mcg

Thymalin

5–10 mg

Frequency

Once daily

Administration

Subcutaneous injection

Intramuscular injection

Cycle Length

4-6 weeks

Onset Speed

Moderate (1-2 weeks)

Evidence Level

Limited human trials

Efficacy

Benefitratings

Immune Restoration

Anti-Inflammatory

Age-Related Immune Decline

Longevity Support

Disease Prevention

Technical Data

Compoundspecifications

Molecular Formula

C33H54N12O15

Molecular Weight

858.9 g/mol

Half-Life

Approximately 2 hours

Bioavailability

Low oral bioavailability (injected administration required)

CAS Number

63958-90-7

Complex mixture; active dipeptide EW: C16H19N3O5

Polypeptide complex; components 250-1000 Da; active dipeptide EW ~321 Da

Not precisely characterized for complex; immune effects persist weeks post-administration

High via intramuscular or subcutaneous injection

Protocols

Dosingtiers

standard

1-2 mg

Once daily (often dosed in the evening)

10-20 day courses, repeated cyclically

Research-practice dosing for immune support; thymulin requires injectable delivery due to low oral bioavailability and a zinc ion for activity, so zinc co-supplementation is commonly paired [1].

starting

100-400 mcg

Three times weekly

Several weeks

Lower microgram-range intradermal dosing is used in some research protocols as a conservative entry point [1].

5-10 mg reconstituted in saline

5-10 day course, often repeated every 6 months

Reflects the Russian clinical course used in immune-restoration and gerontology protocols, typically 10 mg IM daily for 5-10 days [1].

advanced

10 mg

Up to 20 day course, repeated every 6 months

Subcutaneous administration is used in community practice at the same 10 mg daily dosing; longer 20-day courses are described for cyclical immune support [1].

Applications

Bestsuited for

Thymulin levels naturally drop significantly in elderly populations. Supplementation can restore T cell maturation and immune responsiveness in aging. Research shows thymulin can reverse age-related thymic involution and restore helper/suppressor T cell balance.

Recovery from Severe Malnutrition

In severely malnourished individuals, the thymus shrinks and T cell development is impaired. In vitro studies show thymulin can restore T cell maturation even in those with thymic involution, making it useful in recovery protocols.

Chronic Inflammatory Conditions

Thymulin inhibits NF-κB activation and suppresses pro-inflammatory cytokines (IL-6, TNF-α, IL-8). Animal models show effectiveness in lung diseases, inflammatory pain, and neuroinflammation. Anti-inflammatory effects work through p38 MAPK suppression.

Aging Adults Seeking Immune Support

Thymalin is especially valuable for people over 55 whose thymus gland has naturally shrunk with age. By stimulating thymic function, it helps restore the immune training center that your body relies on to fight infections and stay healthy.

Longevity and Anti-Aging Protocols

Clinical studies tracking patients for 6-8 years showed Thymalin reduced mortality by 2.0-2.1-fold. Combined with Epitalon, the mortality reduction reached an impressive 4.1-fold, making this combination one of the most studied longevity peptide protocols.

Seasonal Illness Prevention

Research shows Thymalin cuts respiratory infection rates by 2.0-2.4-fold. A short 10-day course before cold and flu season can significantly boost your immune defenses for months afterward.

Safety Profile

Sideeffects

Common

Local injection site reactions

Mild fatigue or lethargy

Transient headache

Uncommon

Mild fever or chills

Sleep disturbance or vivid dreams

Appetite changes

Transient lymph node swelling

Serious

Severe allergic reaction

Uncontrolled immune activation

No side effects in most patients

Mild injection site reaction

Transient low-grade fever

Mild flu-like symptoms

Temporary headache

Research Status

Safety& evidence

FDA Status

Research compound

Safety Overview

Thymulin is a naturally occurring thymic hormone with favorable safety profile in research. No reported serious adverse events in animal models even at high doses. Limited human safety data but observed studies suggest good tolerability. Requires concurrent zinc supplementation for biological activity and additional safety assurance. Most concerns relate to immune overactivation in susceptible individuals, not direct peptide toxicity.

Contraindications

xUncontrolled autoimmune disease

xSevere zinc deficiency requiring IV repletion

xThymic tumors or malignancies

xPregnancy (limited safety data)

Thymalin has an excellent safety profile based on over 40 years of clinical use in Russia. Most patients experience zero side effects, and the peptide complex has been described as 'practically non-toxic' in research literature. It has been used safely in thousands of patients, including elderly populations over extended periods.

xActive thymic tumors or malignancies

xKnown hypersensitivity to animal-derived peptide products

xPregnancy and breastfeeding (insufficient safety data)

xSevere uncontrolled autoimmune disease without medical supervision

Decision Guide

Which isright for you?

Choose Thymulin (FTS) if...

Immune system restoration

T cell maturation in immunocompromised states

Age-related immune decline

Chronic inflammatory conditions

Choose Thymalin if...

Immune system restoration in aging adults

Longevity and healthy aging support

Reducing infection frequency and severity

Multi-system health optimization