Thymalin vs Thymopoietin
Russian thymic peptide complex that rejuvenates immune function and supports healthy aging
Thymic hormone that supports T-cell development and immune function, with the active fragment thymopentin (TP-5) used in clinical research
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Thymalin
5–10 mg
Thymopoietin
50–50 mg
Frequency
Thymalin
Once daily
Thymopoietin
Every other day
Administration
Thymalin
Intramuscular injection
Thymopoietin
Subcutaneous injection
Cycle length
Thymalin
4-6 weeks
Thymopoietin
4-6 weeks
Onset speed
Thymalin
Moderate (1-2 weeks)
Thymopoietin
Moderate (1-2 weeks)
Evidence level
Thymalin
Limited human trials
Thymopoietin
Limited human trials
Benefit ratings
Immune Restoration
Longevity Support
Disease Prevention
Immune Cell Development
Post-Surgical Recovery
Cancer Immunotherapy Enhancement
Compound specifications
Thymalin
Molecular formula
Complex mixture; active dipeptide EW: C16H19N3O5
Molecular weight
Polypeptide complex; components 250-1000 Da; active dipeptide EW ~321 Da
Half-life
Not precisely characterized for complex; immune effects persist weeks post-administration
Bioavailability
High via intramuscular or subcutaneous injection
CAS number
63958-90-7
Thymopoietin
Molecular formula
C246H404N66O73
Molecular weight
5454
Half-life
Minutes to hours in plasma
Bioavailability
Moderate with subcutaneous injection
CAS number
67632-30-6
Dosing compared
Thymalin
Intramuscular injection
5-10 mg reconstituted in saline
Once daily · 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].
Subcutaneous injection
10 mg
Once daily · 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].
Thymopoietin
Subcutaneous injection
50 mg (as the active thymopentin/TP-5 pentapeptide)
Three times weekly · 6 weeks to several months
The full-length thymopoietin hormone is not dosed directly in humans; its immune activity is delivered clinically through its active pentapeptide fragment thymopentin (TP-5), studied at 50 mg SC three times weekly [5].
Best suited for
Thymalin
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.
Thymopoietin
Cancer Treatment Support
Used alongside chemotherapy to maintain immune function and reduce treatment side effects while enhancing anti-tumor immunity
Post-Surgical Immune Recovery
Helps restore T-cell function and prevent immune depression following major surgery or serious medical stress
HIV-Related Immune Support
Combined with antiretroviral therapy to support T-cell populations and improve immune response
Side effects
Thymalin
Common
- No side effects in most patients
- Mild injection site reaction
Uncommon
- Transient low-grade fever
- Mild flu-like symptoms
- Temporary headache
Serious
- Severe allergic reaction
Thymopoietin
Common
- Injection site redness or swelling
- Mild fever
- Transient lymphocytosis
Uncommon
- Mild to moderate fatigue
- Temporary headaches
- Joint or muscle aches
Serious
- Neuromuscular weakness or myasthenia-like symptoms
- Severe allergic reaction (anaphylaxis)
- Autoimmune flare
Safety & evidence
Thymalin
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
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.
Contraindications
- Active thymic tumors or malignancies
- Known hypersensitivity to animal-derived peptide products
- Pregnancy and breastfeeding (insufficient safety data)
- Severe uncontrolled autoimmune disease without medical supervision
Thymopoietin
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
Thymopoietin is a naturally-derived thymic hormone with a well-characterized mechanism but limited human safety data. Most clinical experience comes from thymopentin (TP-5), the active pentapeptide fragment. It is generally well-tolerated but has important safety considerations, particularly regarding neuromuscular effects.
Contraindications
- Myasthenia gravis or other neuromuscular junction disorders
- Active autoimmune diseases
- Pregnancy and breastfeeding
- Severe allergic reactions to thymic proteins
Which is right for you?
Choose Thymalin if...
- Immune system restoration in aging adults
- Longevity and healthy aging support
- Reducing infection frequency and severity
- Multi-system health optimization
Choose Thymopoietin if...
- Supporting immune function during cancer treatment
- Recovering immune function after surgery
- Managing HIV-related immune deficiencies
- Enhancing response to other immunotherapies