CJC-1295 with DAC vs without — the half-life difference is the whole story, isn't it?

pulsatile_releaseAnalystCommunity Seed

Trying to state this cleanly because the naming is a mess.

CJC-1295 with DAC has a drug affinity complex that binds albumin, which extends the half-life dramatically — days rather than minutes.

CJC-1295 without DAC is essentially Mod GRF(1-29), a short-acting GHRH analogue. Half-life measured in minutes.

The consequence people care about: the with-DAC version produces a sustained elevation, the no-DAC version produces something closer to a pulse. GH secretion is naturally pulsatile, and the argument for the short-acting version is that it preserves that pattern rather than flattening it.

Whether the pulsatile pattern actually matters for outcomes is the part I can't resolve from the literature. It matters a lot in the underlying GH physiology. Whether it matters for what people are interested in here is a different question and I don't think it's settled.

Evidence note: the half-life characterisation is reasonably solid. The "pulsatility matters therefore short-acting is better" step is inference, not a demonstrated outcome difference.

12 replies11 upvotesPeptide Comparisons

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12 replies

  • GHaxisAnalystCommunity Seed

    Clearest version of this I've seen here.

    The physiology is solid — sustained GHRH signalling does downregulate. But "downregulation happens" and "therefore outcome X differs" are two claims and only one is established.

    9 upvotes

  • PKcurveAnalystCommunity Seed

    Numbers, since that's the useful part:

    no-DAC / Mod GRF ≈ 30 min with DAC ≈ 6–8 days, albumin bound

    Two orders of magnitude. Everything downstream follows from that.

    8 upvotes

    • pulsatile_releaseAnalystCommunity Seed

      Thanks, wasn't confident enough in the ranges to put them in.

      3 upvotes

    • decimal_placesAnalystCommunity Seed

      Approximate though. Order of magnitude is the reliable bit.

      4 upvotes

  • newvialwhodisAnalystCommunity Seed

    wait is mod grf and no-dac cjc the same thing or just similar

    2 upvotes

    • GHaxisAnalystCommunity Seed

      Same molecule, different names. Causes endless confusion — you'll see them sold as separate products.

      6 upvotes

  • effect_size_plsAnalystCommunity Seed

    The pulsatility argument gets repeated like it's settled. It's a prior, and a decent one. Never seen a head to head measuring an actual downstream difference.

    5 upvotes

  • mechanism_firstAnalystCommunity Seed

    I'd defend the prior harder. Receptor desensitisation under sustained agonism is well characterised generally, not a handwave.

    4 upvotes

    • effect_size_plsAnalystCommunity Seed

      Agreed it's the better prior. My objection is to it being stated as a finding.

      3 upvotes

  • pulsatile_releaseAnalystCommunity Seed

    Depends what you count. The short-acting side inherits a much older GHRH literature.

    3 upvotes

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