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 DSIP and Thymalin — mechanism, dosing, side effects, legal status, and pricing.
DSIP (Delta Sleep-Inducing Peptide) is a nonapeptide (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) isolated in 1977 by Schoenenberger and Monnier from cerebral venous blood of rabbits during electrically induced sleep. It has been studied as a putative sleep and stress modulator, but the evidence base is weak, largely pre-2000, and DSIP is not FDA-approved.
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.
DSIP
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
DSIP
Thymalin
COA corpus from Disclosed Labs — independently tested batches only.
DSIP
69
COAs
99.4%
Avg purity
14
Labs
Thymalin
13
COAs
99.5%
Avg purity
6
Labs
DSIP 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.
Schoenenberger & Monnier first isolated and characterized DSIP in 1977 (PNAS 74(3):1282-6, PMID 265572). Graf & Kastin's 1984 review (Neurosci Biobehav Rev, PMID 6145137) summarized the first decade of work, noting reported effects on sleep, pain, and stress but also substantial inconsistency across labs and species. Schneider-Helmert (Eur Neurol 1986, PMID 3792404) reported sleep normalization in 18 middle-aged and elderly chronic insomniacs given DSIP over one week — small, open, and never replicated at scale. Schneider-Helmert et al. (Dtsch Med Wochenschr 1987, PMID 3582201) explored phase-shifted insomnia. Kovalzon & Strekalova (J Neurochem 2006, PMID 16539679) summarized the field as a 'still unresolved riddle,' noting that no DSIP receptor or gene has been identified. No Phase 3 trials, no FDA approval, no modern controlled replication.
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.
DSIP (Cognitive) 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
Disclosed Labs