Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of FOXO4-DRI and Thymalin — mechanism, dosing, side effects, legal status, and pricing.
FOXO4-DRI is a D-retro-inverso peptide designed to disrupt the FOXO4-p53 interaction in senescent cells. It is studied as a senolytic agent that selectively induces apoptosis in senescent cells while sparing normal cells.
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.
FOXO4-DRI
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
FOXO4-DRI
Thymalin
COA corpus from Disclosed Labs — independently tested batches only.
FOXO4-DRI
5
COAs
99.5%
Avg purity
4
Labs
Thymalin
13
COAs
99.5%
Avg purity
6
Labs
Baar et al. (Cell, 2017, PMID 28340339) identified FOXO4 as a pivot for senescent-cell viability and designed a cell-penetrating D-retro-inverso peptide that disrupts the FOXO4-p53 interaction, selectively triggering apoptosis in senescent cells while sparing proliferating cells. In vivo, the peptide neutralized doxorubicin chemotoxicity and, in fast-aging XpdTTD/TTD and naturally aged mice, restored fur density, renal function, and fitness. This is the only primary in vivo study; evidence is preclinical only. No human clinical trials have been registered or completed. Safety in humans is unknown — as a systemic senolytic inducing apoptosis, theoretical risks include impaired wound healing, immune perturbation, and off-target effects on quiescent stem-cell populations.
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
FOXO4-DRI (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
Side Effects
Contraindications
Lab Testing