Research peptide article

Selank and Semax: Two Synthetic Nootropic Research Peptides

Published June 9, 2026 · PX-Labs

For laboratory and research reference only. All compounds discussed are sold strictly for scientific research purposes and are not intended for human or veterinary use.

Overview

Selank and Semax are two synthetic peptides studied in the nootropic and neuropeptide research category. Both are Russian-developed research peptides based on naturally occurring sequences, and both are frequently examined together. This article covers their structural origins and what distinguishes them.

Selank

Selank is a synthetic heptapeptide — a seven-amino-acid chain — developed as a stabilized analog of the naturally occurring tetrapeptide tuftsin. The synthetic modifications give it greater stability than the native sequence as a research compound.

Structure

Synthetic heptapeptide, tuftsin analog

Available from PX-Labs

Selank — 5mg, 10mg

Semax

Semax is a synthetic peptide based on a fragment of the adrenocorticotropic hormone (ACTH) sequence — specifically a modified form of the ACTH(4-10) fragment, with structural changes for stability.

Structure

Synthetic ACTH(4-10) fragment analog

Available from PX-Labs

Semax — 10mg

How They Differ

The two come from different parent sequences: Selank derives from tuftsin, Semax from an ACTH fragment. They are not variants of one another. What groups them is research context — both are synthetic neuropeptides studied in the same broad category, and researchers working in that area often examine both.

Handling

Both are supplied lyophilized and follow standard peptide handling: refrigerated or frozen storage of the lyophilized powder, protection from light and moisture, refrigerated storage of reconstituted solution. Bacteriostatic water is used for reconstitution.

Research Use Only

Selank and Semax are sold strictly for laboratory and scientific research. They are not intended for human or veterinary use. PX-Labs is a research chemical supplier, not a compounding pharmacy, and does not provide usage, dosing, or application guidance.