If you are hoping a peptide will fix your sleep, the evidence is thin and mixed. The best studied is growth-hormone-releasing hormone, or GHRH. It changed sleep in lab studies, but the effect depended on your sex, your age and the time of night it was given.
Most of those studies gave the hormone by vein or nasal spray, for a few nights at most. Only one ran for months, and it rated sleep by questionnaire. For the goal as a whole, see the sleep goal page.
Why GHRH and sleep are linked
GHRH tells the pituitary to release growth hormone. Sermorelin is a short piece of it, and how sermorelin compares with ipamorelin is covered separately. Researchers noticed that GHRH promotes sleep in animals. The question was whether it does in people.
In young men: more deep sleep
A 1993 study gave healthy young men small doses of GHRH by vein during sleep [1]. Given early in the night, it did not change deep sleep but raised REM sleep.
Given later, in the third REM period, it cut time awake and raised deep sleep almost 10-fold. The authors concluded it promotes sleep, most of all when the drive to sleep is low.
A 1999 study tried a nasal spray. Twelve young and 11 older men took 300 micrograms of GHRH or placebo before bed [2]. GHRH raised REM and deep sleep, mostly in the second half of the night. The effect did not depend on age.
In young women: worse sleep
A 2007 study asked the same question in healthy young women [3]. They got GHRH by vein in four pulses, at two dose levels, timed to the same point in the menstrual cycle.
Compared with placebo, REM sleep fell on the lower dose. The deepest stage of sleep fell on the higher dose. The authors concluded that GHRH impairs sleep in women.
In older adults: a smaller effect
A 1997 study gave GHRH by vein to 13 healthy adults with a mean age of 69 [4]. Night-time awakenings fell and the first deep-sleep period lengthened. But the authors found the effect much smaller than in young people.
A longer trial tested a modified GHRH, given nightly under the skin, in 19 adults aged 55 to 71 [5]. After 16 weeks, self-rated sleep quality had not changed in either men or women. This was an analog, not sermorelin itself.
DSIP: the peptide named for sleep
Delta sleep-inducing peptide sounds like the answer. Two small human trials in chronic insomnia tested it by vein.
In one double-blind trial (n = 16), patients got DSIP or placebo for three nights [6]. Sleep efficiency rose slightly. But the authors called the effects weak and partly due to a change in the placebo group. They concluded DSIP is not likely to be of major benefit.
In the other, insomniacs got DSIP or placebo for four nights in a crossover design [7]. Some measures differed from placebo, but they had differed at baseline too. The authors called the improvement of little clinical significance.
The FDA lists DSIP, under the name emideltide, among withdrawn compounding nominations [8]. It says it has no safety information for the proposed route. FDA reviewed it again for a July 2026 advisory meeting, for insomnia among other uses. Its briefing concluded the balance “weighs against” listing it [9]. The committee voted against it too [10]. That leaves DSIP research-only.
What to take from this
None of these studies tested a peptide over weeks in people with a sleep problem. The GHRH results are real, but short and lab-based. They also split by sex.
If sleep is your goal, ask a prescriber what has been tested in people like you. The doses and side effects of the approved GHRH fragment are in sermorelin dosage and sermorelin side effects. The legal status of the others is in are peptides legal.