Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of GHK and Thymalin — mechanism, dosing, side effects, legal status, and pricing.
GHK is the parent tripeptide Gly-His-Lys, originally isolated from human plasma by Loren Pickart (1973) as an activity that caused aged hepatocytes to synthesize proteins like younger tissue. It is DISTINCT from GHK-Cu, the 1:1 copper(II) complex tracked as a separate entry — but GHK binds copper readily in vivo, so in physiological environments the bare peptide rapidly associates with available Cu(II). Not FDA-approved for any indication; used in cosmetic and research contexts only.
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.
GHK
Thymalin
Category
Legal Status
Mechanism
Dose Range
Route
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
GHK
Thymalin
COA corpus from Disclosed Labs — independently tested batches only.
GHK
No COA data yet.
Submit testing data →Thymalin
13
COAs
99.5%
Avg purity
6
Labs
GHK is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. Thymalin remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
The overwhelming majority of GHK research uses the GHK-Cu complex; direct studies of copper-free GHK are limited. Pickart (J Biomater Sci Polym Ed, 2008, PMID 18644225) reviewed GHK's role in tissue remodeling and wound healing. Pickart et al. (Oxid Med Cell Longev, 2012, PMID 22666519) reviewed GHK-Cu in oxidative stress and cognitive aging. Pickart, Vasquez-Soltero & Margolina (BioMed Res Int, 2014, PMID 25302294; 'GHK and DNA: Resetting the Human Genome to Health') summarized microarray data indicating GHK modulates expression of thousands of human genes. No human clinical trials exist for injected bare GHK; cosmetic formulations typically use topical GHK or GHK-Cu at ~50–200 ppm.
Key references
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.
GHK (Cosmetic) and Thymalin (Immune) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Frequency
Dosing Notes
Side Effects
Contraindications
Lab Testing
Disclosed Labs