Thymalin vs Thymopentin (TP-5)
Russian thymic peptide complex that rejuvenates immune function and supports healthy aging
Immune-boosting pentapeptide fragment that enhances T-cell function and dendritic cell maturation
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
Thymopentin (TP-5)
50–50 mg
Frequency
Thymalin
Once daily
Thymopentin (TP-5)
Once daily
Administration
Thymalin
Intramuscular injection
Thymopentin (TP-5)
Subcutaneous injection
Cycle length
Thymalin
4-6 weeks
Thymopentin (TP-5)
4-6 weeks
Onset speed
Thymalin
Moderate (1-2 weeks)
Thymopentin (TP-5)
Moderate (1-2 weeks)
Evidence level
Thymalin
Limited human trials
Thymopentin (TP-5)
Moderate human trials (Phase 1-2)
Benefit ratings
Immune Restoration
Longevity Support
Disease Prevention
Immune Enhancement
Cardiovascular Support
Post-Recovery Support
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
Thymopentin (TP-5)
Molecular formula
C30H49N9O9
Molecular weight
679.8
Half-life
30 seconds to few minutes in plasma
Bioavailability
Sustained release via subcutaneous route
CAS number
69558-55-0
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].
Thymopentin (TP-5)
Subcutaneous injection
50 mg
Three times weekly · 6 weeks to 48 weeks depending on indication
Dose used in controlled clinical trials, e.g. 50 mg SC three times weekly in HIV and atopic dermatitis studies [5].
Intravenous injection
50 mg by slow IV
Repeated injections (e.g. three times weekly) · Several weeks
Slow intravenous infusion was used in rheumatoid arthritis trials and may enhance in-vivo potency versus bolus dosing [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.
Thymopentin (TP-5)
Immune System Enhancement
Thymopentin directly increases T-cell function and promotes dendritic cell maturation, making it ideal for people seeking to boost immune response naturally
Cardiac Health Support
Clinical trials show thymopentin improves ejection fraction and exercise capacity in elderly heart failure patients while enhancing immune markers
Post-Surgery Recovery
Helps restore immune function after major surgery and protects important immune responses during recovery period
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
Thymopentin (TP-5)
Common
- Local injection site reaction
- Mild fatigue
- Transient fever
Uncommon
- Muscle aches
- Mild headache
Serious
- Allergic reaction
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
Thymopentin (TP-5)
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
Thymopentin is well-tolerated with minimal side effects reported in clinical trials. Most adverse events are mild and local. No serious safety concerns have emerged from decades of clinical use in China and Europe.
Contraindications
- Pregnancy and breastfeeding
- Active malignancy (without medical supervision)
- Severe immunosuppression
- Hypersensitivity to peptide medications
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 Thymopentin (TP-5) if...
- Immune system strengthening
- Recovering from illness or surgery
- Managing autoimmune conditions
- Supporting cardiac health in elderly patients