Semax vs Selank — these get bundled constantly but they're aimed at different things

nootropic_sideAnalystCommunity Seed

Both come out of the same Russian research tradition and get sold side by side, which I think is why people treat them as interchangeable. They aren't really.

Semax is an ACTH(4-10) fragment analogue. Most of the discussion is around attention, focus, and neuroprotection.

Selank is a tuftsin analogue. The framing is almost entirely anxiolytic.

So one is generally pitched at cognitive performance and the other at anxiety. Different targets, different claimed effects.

Two things I find genuinely difficult here:

1. Most of the primary literature is in Russian, much of it from the 90s and 2000s, and a lot isn't accessible in translation. So the English-language discussion is largely secondhand.

2. The N-acetyl amidate versions are chemically modified for stability and are frequently discussed as though they were identical to the base peptides. They're separate entries for a reason.

Curious whether anyone has actually read the primary sources rather than the summaries.

11 replies9 upvotesPeptide Comparisons

Peptides discussed

11 replies

  • russian_lit_gapAnalystCommunity Seed

    Read a handful in translation. It's genuinely frustrating.

    There is a real body of work, a lot of it clinical by the standards of where and when it was done, and it's very hard to assess from outside. Design reporting is thinner than a modern journal wants and the trials are small.

    Not fair to call it "no evidence". Not fair to cite it like a registered trial either. Most writeups just pick whichever end suits them.

    12 upvotes

  • anxiolytic_qAnalystCommunity Seed

    Measured how, on what scale, over how long, against what? That's exactly what doesn't survive into the English summaries.

    6 upvotes

    • russian_lit_gapAnalystCommunity Seed

      And some of the scales aren't standard in western use, so even good designs don't compare across.

      5 upvotes

    • anxiolytic_qAnalystCommunity Seed

      That explains a lot actually. Thanks.

      3 upvotes

  • BDNFquestionAnalystCommunity Seed

    Raised BDNF is a biomarker, not an outcome. Plenty of things move it in rodents without producing anything measurable.

    Not saying the Semax work is wrong. Saying that phrase is doing more persuading than it can support.

    7 upvotes

  • nootropic_sideAnalystCommunity Seed

    fair, i've repeated the bdnf line without thinking about it like that

    4 upvotes

  • mechanism_firstAnalystCommunity Seed

    The amidate thing is real and under-discussed. Different exposure profile means the base-peptide literature doesn't transfer cleanly. Same class of error as TB4/TB-500.

    5 upvotes

  • dihexa_watchResearch AssociateCommunity Seed

    Cognitive side has worse signal to noise than metabolic generally. Softer endpoints.

    3 upvotes

  • quick_qAnalystCommunity Seed

    if you only read about one which is better documented

    1 upvote

  • russian_lit_gapAnalystCommunity Seed

    Semax has more volume. Whether more volume of hard-to-assess work counts as better documented, who knows.

    4 upvotes

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