DSIP: named for an effect that has been hard to reproduce

A peptide whose name is a claim, made in 1974, that the subsequent fifty years have not settled. That is unusual and worth knowing before reading anything else about it.

Where the name came from

Animal-only or theoretical DSIP was isolated from the blood of rabbits in induced slow-wave sleep and named for what it appeared to do when transferred: increase delta sleep in recipients. That original finding is real and is where the name comes from. What happened afterwards is the interesting part — replication was inconsistent, the sleep effect proved difficult to demonstrate reliably in later work, and the peptide’s endogenous role has never been clearly established.

Later research has been more interested in it as a stress-response modulator than as a hypnotic: effects on ACTH and cortisol, on stress-induced physiological changes, and some antioxidant activity. Those are the mechanisms most often cited now, and they are a different account from the one the name implies.

The app models a very short half-life and flags it as an estimate, which is consistent with a small peptide and means limited or absent human pharmacokinetic data. Anything calculated from it inherits that.

What the sleep claim rests on

Animal-only or theoretical Human work exists and is small, old and mixed. Some studies in people with disturbed sleep reported improvements in sleep onset and subjective quality; others found little. There is no modern randomised trial with polysomnography as the endpoint, which is what would actually settle whether it increases slow-wave sleep in people.

The reason that matters more than usual: sleep is one of the most placebo-responsive things anyone measures, and self-reported sleep quality is unusually easy to shift with expectation and with the ritual of taking something at bedtime. A compound whose only available assessment is subjective, taken for an outcome that responds strongly to expectation, is close to the worst case for judging by feel. A consumer sleep tracker is not polysomnography, but it is at least an external measurement, and it is what the app’s own monitoring note suggests.

Off-label or community practice The use that has more internal logic is the one the app’s entry mentions in passing: growth hormone secretagogues taken too late disrupt sleep architecture, and DSIP is described in that context as a corrective. That is a hypothesis about an interaction rather than a finding, and the simpler answer to a secretagogue disrupting sleep is usually to move the secretagogue.

Sourcing, tolerance and the alternative worth naming

There is no approved product anywhere. Identity and purity rest with whoever made the vial, and this site names no vendor or testing service. The app’s rows describe intermittent rather than nightly use, on the basis that tolerance develops — plausible for any sleep agent and not demonstrated for this one.

The comparison worth making is with things that have been studied properly. Sleep is one of the few areas in this reference where the boring interventions have strong evidence: cognitive behavioural therapy for insomnia outperforms hypnotics in trials and holds up after treatment stops. A person taking an unstudied peptide for chronic insomnia has usually not tried the thing that works.

Persistent sleep disruption is also a symptom rather than a diagnosis — sleep apnoea, depression, thyroid disease and a long list of medications all cause it, and all of them are worth excluding before treating the symptom. That conversation belongs with a clinician, and anything on the drawbacks list below belongs in it too.

How long one dose lasts

Try other intervals on the half-life and steady-state calculator, which runs the same function against whatever cadence you type.

The dosing rows the app records

Animal-only or theoretical Reproduced from the app’s reference so you can see what it holds, not as a recommendation. Which row applies to a particular person, if any, is a clinical decision this page does not make — and rows describing supraphysiological or post-cycle use are filtered out before this table is built, so what you see here is a subset.

What the app monitors alongside it

The panel below is the app’s own monitoring note for DSIP, verbatim. None of the analytes it names has a page here yet.

Drawbacks and risks the app records

From the app’s own entry. The first item is doing the most work: for a compound named after an effect, the absence of large-scale human data on that effect is the story.

• Limited large-scale human trial data
• Not FDA approved
• Quality sourcing critical
• May cause vivid dreams initially
• Tolerance may develop with daily use — cycle recommended
• Intranasal or SubQ required — no oral bioavailability

Questions people actually ask

Does it actually increase deep sleep?

The original 1974 work said so and later replication has been inconsistent. There is no modern randomised trial with polysomnography as an endpoint, which is what would answer it.

Why is the assessment so unreliable?

Because self-reported sleep quality responds strongly to expectation, and a bedtime ritual is itself an intervention. A tracker is not polysomnography but it is at least external, which is why the app suggests one.

Should it be taken every night?

The app’s rows describe intermittent use on the basis that tolerance develops. That is plausible for any sleep agent and has not been demonstrated for this one specifically.

What has better evidence for insomnia?

Cognitive behavioural therapy for insomnia, which outperforms hypnotic drugs in trials and keeps working after treatment ends. It is also worth excluding sleep apnoea, thyroid disease, depression and medication effects before treating sleep as the problem.

Where the load-bearing numbers come from

Named rather than linked. Publisher URLs move, and a citation that resolves to a 404 two years from now is worse than one you can search for by name — every entry below is findable from the title and year alone.