Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of MOTS-c and Thymalin — mechanism, dosing, side effects, legal status, and pricing.
MOTS-c is a 16-amino-acid mitochondrial-derived peptide (MDP) encoded within the mitochondrial 12S rRNA, discovered by Lee and Cohen at USC in 2015 (sequence: MRWQEMGYIFYPRKLR). It is an investigational, research-only peptide studied as a metabolic regulator; it has not been approved by the FDA for any indication.
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.
MOTS-c
Thymalin
Category
Legal Status
Mechanism
Dose Range
Route
Frequency
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
MOTS-c
Thymalin
COA corpus from Disclosed Labs — independently tested batches only.
MOTS-c
193
COAs
99.5%
Avg purity
16
Labs
Thymalin
13
COAs
99.5%
Avg purity
6
Labs
Lee et al. (Cell Metabolism, 2015; PMID 25738459) identified MOTS-c and showed that exogenous administration in mice prevented diet-induced obesity and insulin resistance via AMPK activation in skeletal muscle. Kim et al. (Cell Metabolism, 2018; PMID 29983246) demonstrated that MOTS-c translocates to the nucleus under metabolic stress and regulates antioxidant response element (ARE) genes. Reynolds et al. (Nature Communications, 2021; PMID 33473109) reported that exercise induces MOTS-c in human skeletal muscle and that MOTS-c treatment improved physical capacity in young, middle-aged, and aged mice. Human clinical data are limited to CohBar's Phase 1a/1b study of the analog CB4211 in healthy volunteers and obese NAFLD subjects, which reported acceptable tolerability and exploratory signals on ALT/AST and glucose; CohBar wound down the program in 2023. No completed Phase 2 or Phase 3 trials exist for MOTS-c or its analogs, and grey-market dosing (typically ~10 mg SubQ 2-3x/week) is not clinically validated.
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.
MOTS-c (Metabolic) 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.
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing