# The hours after DSIP

> Human sleep observations | Big Sky Peptides — Big Sky Peptides examines a small human DSIP sleep study, falling plasma signals at sleep onset and observations during activity and constant bed rest.

**Insomnia and blood measurements**

A first hour and a second hour make different impressions on me. I distrust a smooth account that folds them together.

## Six people with chronic insomnia

In [the small human study of synthetic DSIP](https://pubmed.ncbi.nlm.nih.gov/7028502/), six middle-aged people with chronic insomnia received the peptide intravenously. The report described longer sleep, fewer interruptions, slightly more REM sleep and no daytime sedation. The sleep-promoting effect appeared in the second hour after injection; the first hour included slight arousal.

I give the sequence more weight than the appealing phrase no daytime sedation. The reported benefit came with a temporal shape, and erasing the early arousal would turn the account into something smoother than the experiment. It also matters that these were people with chronic insomnia. The finding concerns that small group under the study's conditions.

That inconvenient first hour earns some trust from me. A small report still leaves the breadth and durability of any benefit unsettled.

![Illustration of an empty sleep-recording bed while an adult technician arranges disconnected electrode leads beside it.](images/sleep-recording-room.webp)

*Illustrated sleep-recording room prepared for a study night, imagined rather than reconstructed.*

## A plasma signal at sleep onset

A different kind of human experiment [measured DSIP-like immunoreactivity in seven healthy men](https://pubmed.ncbi.nlm.nih.gov/8745061/). That term describes what the assay recognises as DSIP-like material. The plasma signal decreased at the transition from waking to sleep, both in evening sleep and in morning recovery sleep, with no sleep-stage specificity.

I expected a substance named for inducing sleep to offer a conveniently rising signal. This finding sent that expectation downhill. The observation gives the beginning of sleep a relationship with a falling blood measurement; it does not establish that administering DSIP reproduces the process.

The two human experiments ask different questions. One administered synthetic DSIP to people with chronic insomnia. The other measured a DSIP-like signal as healthy men fell asleep. Both are interesting enough to retain their separate identities.

## Activity and constant bed rest

In [a study comparing usual activities with constant bed rest](https://pubmed.ncbi.nlm.nih.gov/7895296/), five normal men had hormones and neurotransmitters sampled every half hour. Across the 34-hour bed-rest condition, the temporal pattern and absolute plasma concentrations of DSIP and its phosphorylated form showed no or minimal change between conditions, while heart rate, temperature, LH and TSH changed.

The steady DSIP measurements are a welcome complication for me. A change to the surroundings need not shift every measured signal. Here, several measures responded while the DSIP measurements were comparatively stable. The earlier sleep-onset observation and this bed-rest comparison describe different transitions, and I hesitate to force them into an argument about a single universal DSIP rhythm.

## Human sleep regulation

A [review of neuropeptides and human sleep](https://pubmed.ncbi.nlm.nih.gov/9456470/) concluded that DSIP's impact on human sleep regulation remained unclear. A later [review devoted to DSIP](https://pubmed.ncbi.nlm.nih.gov/16539679/) judged the sleep-promoting evidence weakly documented and described unresolved questions about a gene, precursor protein and receptor.

Those conclusions fit my discomfort with turning the small insomnia report into a settled account of how human sleep works. The reported sleep improvements deserve attention. So do the odd timing, the assay's DSIP-like signal and the much larger biological explanation still missing. These papers cannot establish long-term safety or a dependable treatment for insomnia.

[The delivery experiments](/delivery) add another complication: native DSIP, a phosphorylated form and a fusion peptide can behave differently. The material reaching the body is part of the scientific question.

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At Big Sky Peptides the published DSIP experiments take me through artificial nights; the essays here offer no medical advice.