Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Thymalin and Thymulin — mechanism, dosing, side effects, legal status, and pricing.
Thymalin is a heterogeneous polypeptide extract from calf thymus (a mixture, not a single defined peptide) developed in the 1970s by V. Kh. Khavinson and V. G. Morozov at the Military Medical Academy / St. Petersburg Institute of Bioregulation and Gerontology. Registered as a pharmaceutical in the USSR/Russia for immunocorrection. Distinct from Thymulin (Bach's zinc-dependent nonapeptide pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, originally called FTS) and from Thymosin alpha-1 (a 28-amino-acid synthetic peptide). Not FDA-approved in the US; research-use only.
Thymulin is a zinc-dependent nonapeptide (pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn) secreted by thymic epithelial cells, originally isolated by Bach and colleagues in the 1970s as 'facteur thymique sérique' (FTS). It is NOT the same compound as Thymalin (a Russian bovine thymus extract) or Thymosin alpha-1 (a separate 28-amino-acid thymic peptide). Thymulin is not FDA-approved; use is research/investigational only.
Thymalin
Thymulin
Category
Legal Status
Mechanism
Dose Range
Route
Frequency
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Thymalin
Thymulin
COA corpus from Disclosed Labs — independently tested batches only.
Thymalin
13
COAs
99.5%
Avg purity
6
Labs
Thymulin
5
COAs
99.5%
Avg purity
4
Labs
Evidence base is almost entirely single-lab (Khavinson/Morozov, St. Petersburg). Long-term observational work in elderly Russian cohorts reported reduced all-cause mortality and lower incidence of respiratory infections with Thymalin (alone or with Epithalamin) over 6–8 years, but these were not blinded Western RCTs and have not been independently reproduced. No FDA-registered clinical trials.
Key references
Bach and Dardenne originally characterized FTS/thymulin and its absolute zinc dependency (Bach & Dardenne, Med Oncol Tumor Pharmacother 1989, PMID 2657247). Prasad et al. (J Clin Invest 1988, PMID 3262625) showed that serum thymulin activity falls in human zinc deficiency and recovers with zinc supplementation. Mocchegiani et al. (Int J Immunopharmacol 1995, PMID 8582782) demonstrated partial reversal of thymic involution with zinc in aged mice. Dardenne & Pleau reviewed zinc-thymulin interactions (Met Based Drugs 1994, PMID 18476235). Safieh-Garabedian et al. (Br J Pharmacol 2002, PMID 12110619) reported analgesic/anti-inflammatory activity of a thymulin-related peptide in rats. There are NO large, modern RCTs of exogenous thymulin in humans; clinical use is experimental.
Thymalin and Thymulin are both in the Immune category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing