Semax vs Selank
Strength for strength, the two cost the same per mg at the two strengths both sell by the single box: at 5mg both $0.908 per mg (XA5, SK5), at 10mg both $0.740 per mg (XA10, SK10). Semax is offered in 2 strengths (5mg to 10mg), Selank in 2 (5mg to 10mg); 1 and 1 of those are on the shelf today.
Prices revised · USD per box of ten · freight included to US addresses from $1,000 of goods · COA per batch · research use only · New to us? What can be checked before you pay
What differs between Semax and Selank
Two heptapeptides sharing the Pro-Gly-Pro tail. Semax is the ACTH (4-7) core Met-Glu-His-Phe plus the tail, and its N-terminal methionine oxidises; Selank is the tuftsin tetrapeptide Thr-Lys-Pro-Arg plus the tail and has nothing in it to oxidise or deamidate. As the sulfoxide, Semax weighs 829.9, 16 above its 813.9, a form Selank cannot take. Masses 813.9 and 751.9.
| Detail | Semax | Selank |
|---|---|---|
| Best price per mg | $0.740 per mg (XA10) | $0.740 per mg (SK10) |
| Price per box sold singly | $45.40 to $73.96 | $45.40 to $73.96 |
| Strengths offered | 2: 5mg, 10mg | 2: 5mg, 10mg |
| Highest price per mg | $0.908 per mg (XA5) | $0.908 per mg (SK5) |
| On the shelf today | 1 of 2 strengths | 1 of 2 strengths |
| Range | Longevity & Nootropic | Longevity & Nootropic |
| Also called | No other name | Selanc and TP 7 |
| Form | Lyophilised powder | Lyophilised powder |
| Molecular weight | 813.9 g/mol | 751.9 g/mol |
| Formula | C37 |
C33 |
| CAS number | 80714-61-0 | 129954-34-3 |
| Release limit | Purity ≥ 98.0 % by RP-HPLC | Purity ≥ 98.0 % by RP-HPLC |
Each line’s own page: Semax and Selank. Reading either certificate: how to read a peptide COA. Checking a batch: verify a batch number. Every line priced: the price list. Checking another supplier’s quote: the price per mg calculator.
Strength for strength
Every strength both are offered in, per mg, the lower figure in bold; stock as this page was opened.
| Strength | Semax | Selank |
|---|---|---|
| 5mg | $0.908 per mg (XA5, low stock) | $0.908 per mg (SK5, low stock) |
| 10mg | $0.740 per mg (XA10, ships in 2 weeks) | $0.740 per mg (SK10, ships in 2 weeks) |
Every strength of both
Compared elsewhere
Pinealon vs Semax
At 10mg: $0.405 per mg (Pinealon, 50-box lots) against $0.740; 3 strengths against 2.
Cerebrolysin vs Semax
$0.032 per mg against $0.740 per mg at best (Cerebrolysin, a 50-box line); 1 strength against 2.
Dihexa vs Semax
At 10mg: $0.426 per mg (Dihexa, 50-box lots) against $0.740; 2 strengths each.
Adamax vs Semax
At 10mg: $1.156 per mg against $0.740; 2 strengths each.
Questions
What is the difference between Semax and Selank?
Two heptapeptides sharing the Pro-Gly-Pro tail. Semax is the ACTH (4-7) core Met-Glu-His-Phe plus the tail, and its N-terminal methionine oxidises; Selank is the tuftsin tetrapeptide Thr-Lys-Pro-Arg plus the tail and has nothing in it to oxidise or deamidate.
Which registry numbers do Semax and Selank carry?
Semax is UNII I5FAL2585H, CAS 80714-61-0, a register entry named from its parts, ACTH (4-7) and Pro-Gly-Pro, which the WHO Drug Dictionary spells out as Met-Glu-His-Phe-Pro-Gly-Pro. Selank is UNII TS9JR8EP1G, CAS 129954-34-3, also listed as Selanc and TP 7; its diacetate has a record of its own, UNII Q94Z9E92UU, and N-acetyl selank, at 793.9, is a different compound.
At which residues do the formulas of Semax and Selank part company?
Only in the first four residues. Each chain closes on the same Pro-Gly-Pro, so C37H51N9O10S and C33H57N11O9 differ by exactly what Met-Glu-His-Phe and Thr-Lys-Pro-Arg differ by. On Semax’s side that is four carbons, one oxygen and its methionine’s sulfur; on Selank’s, six hydrogens and two nitrogens, eleven nitrogens in all to Semax’s nine. Those atoms leave Semax 62.0 above Selank, 813.9 against 751.9.
Which is cheaper per mg, Semax or Selank?
Strength for strength, the two cost the same per mg at the two strengths both sell by the single box: at 5mg both $0.908 per mg (XA5, SK5), at 10mg both $0.740 per mg (XA10, SK10).
What are the molecular weights of Semax and Selank?
Semax’s calculated average mass is 813.93 g/mol and Selank’s 751.89 g/mol, 62.04 apart; in electrospray the ions come at m/z 814.9 and 408.0 (1+ and 2+) for Semax against 752.9 (1+) for Selank. On each certificate the measured mass is matched to the line’s calculated average mass, within about one unit, as how to read a peptide COA sets out.
Are Semax and Selank made to the same specification?
Yes: both are supplied to purity not less than 98.0 percent by RP-HPLC and net content within 5 percent of label, and each certificate reports those with a measured mass, matched to the calculated figure on each sheet. The retest date is on the batch record. What differs is each molecule’s own chemistry, described on its compound page.
Structural facts from each compound’s sheet and profile; prices and stock from the list at the moment this page was opened. How to compare strengths on price.