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DSIP

Also known as: Delta Sleep Inducing Peptide, Delta Sleep Peptide, Factor Delta

1
1 · Natty510 · Enhanced

Lower numbers = closer to natural. Higher numbers = more enhanced.

Why this rating?

DSIP is a sleep-focused neuropeptide with no direct anabolic mechanism. It does not stimulate protein synthesis or act as a GH secretagogue the way CJC-1295/Ipamorelin do. Animal studies (Iyer et al. 1987/1988) suggested it could trigger nocturnal GH pulses and blunt stress-hormone responses, but the controlled human trials that actually tested this found no effect: Giusti et al. (1993) reported no change in GH or prolactin in healthy women, and Späth-Schwalbe et al. (1995) reported no change in CRH- or meal-induced ACTH/cortisol. Any real-world benefit is indirect, via better sleep quality and recovery. Rated 1 (basically natty): it is a sleep aid, not a muscle-, fat-, or hormone-altering compound, and the human data show no measurable GH or cortisol effect, so it does not move the muscular/physique ceiling beyond natural by any established path.

Overview

A 9-amino acid neuropeptide (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, ~849 Da) first isolated from rabbit cerebral venous blood in 1974 and chemically characterized by Schoenenberger & Monnier in 1977. Promotes delta wave (slow-wave) sleep stages 3-4 NREM. Modulates GABA and serotonin systems. Animal studies report increased nocturnal GH pulses and altered stress-hormone responses, but the controlled human trials that tested this directly found no effect on GH/prolactin (Giusti et al. 1993) or on CRH-/meal-induced ACTH/cortisol (Späth-Schwalbe et al. 1995): so the often-repeated GH and cortisol claims are largely unproven in humans. Research peaked in the 1980s-90s but development stalled due to very short half-life and inconsistent clinical results. Evidence quality is low-moderate with mostly small, outdated studies.

Important Warnings

  • NOT approved for human therapeutic use anywhere
  • Evidence quality is LOW-MODERATE (small, outdated studies from 1980s-90s)
  • Inconsistent results in clinical trials - effects vary by individual
  • Very short plasma half-life creates formulation challenges
  • Quality control varies significantly between peptide suppliers
  • No pharmaceutical-grade product exists
  • Avoid with sedatives, benzodiazepines, alcohol (additive sedation)
  • Avoid driving or operating machinery after administration
  • Long-term safety data is absent
  • Mechanism of action incompletely understood

Purpose & Use Cases

Sleep Quality Improvement

Promotes slow-wave (delta) sleep. Reduced sleep latency and improved sleep efficiency in some insomnia studies. Effects may be more pronounced in sleep-disordered individuals than healthy subjects.

GH Enhancement (unproven in humans)

Animal studies (Iyer et al. 1987/1988) report increased nocturnal GH pulse amplitude, often cited as "30-50%" though that figure traces to older/animal work rather than a controlled human trial. The one controlled human trial that tested this, Giusti et al. (1993), found no significant change in GH or prolactin. Not comparable to exogenous GH.

Stress/Cortisol Normalization (unproven in humans)

Improved stress tolerance and stress-hormone markers in animal models (e.g., preserved hypothalamic substance P, blunted adrenal/thymus stress response, Salieva et al. 1992). However, a controlled human trial (Späth-Schwalbe et al. 1995) found DSIP did not alter CRH- or meal-induced ACTH/cortisol secretion, so cortisol-normalizing claims are not established in humans.

Recovery Support

Theoretical improvement through better sleep quality alone (the cortisol-lowering pathway is not confirmed in humans). Any enhanced recovery capacity during intense training periods is indirect.

Benefits

  • May improve slow-wave sleep quality
  • GH pulse increases seen in animal studies, but not confirmed in the one controlled human trial
  • Stress-protective effects seen in animal models; a controlled human trial found no cortisol/ACTH effect
  • Acts as an endogenous stress-limiting factor in animal research
  • Generally well-tolerated with mild side effects (largest human trial, n=107, reported good tolerance aside from occasional headache)
  • No evidence of dependence or tolerance in short-term studies
  • Not currently WADA prohibited
  • Crosses blood-brain barrier effectively

Good to Know

A sleep peptide, not an anabolic

DSIP's job is to promote delta (slow-wave) sleep. Any physique benefit is indirect. Better sleep can support recovery. It does not build muscle or burn fat directly, which is why it sits at a 2, in line with other pure health/recovery peptides (Epithalon, GHK-Cu, ARA-290, Cerebrolysin) that don't move muscular potential beyond natural.

The growth-hormone and cortisol claims are weak in humans

The often-repeated '30-50% increase in nocturnal GH' comes largely from rat studies (Iyer et al. 1987/1988) and older work. The one controlled human trial that tested it, Giusti et al. (1993), found infusing DSIP in healthy women did not change GH or prolactin secretion. Likewise, a separate human trial (Späth-Schwalbe et al. 1995) found DSIP did not affect CRH- or meal-induced ACTH/cortisol. Any GH or recovery benefit is probably secondary to improved sleep, and is nothing like exogenous GH or a secretagogue. Treat the GH/cortisol angle as unproven in humans.

Very short half-life, but effects outlast the peptide

DSIP is cleared from plasma on the order of minutes (estimates across sources range roughly 7-25 minutes) via peptidase degradation, yet its sleep effects have been reported to persist for hours, up to ~20 hours after IV dosing in one human study (Schneider-Helmert & Schoenenberger 1983). It appears to trigger downstream GABA/serotonin cascades that outlast the molecule. The flip side: the short half-life and formulation challenges mean no pharmaceutical-grade product exists and evidence quality is low-to-moderate.

Additive sedation: mind the stack

Because it works partly through GABA, DSIP can add to the sedation of benzodiazepines, alcohol, opioids, and other CNS depressants. Dose it 30-60 min before bed, and do not drive or operate machinery afterward.

Dosage Guidelines

Experience LevelDosage Range
Beginner100100 mcg/day
Intermediate100200 mcg/day
Advanced200300 mcg/day
Frequency
Once daily, 30-60 minutes before bed. Some use 5 days on/2 days off.
Typical Cycle Length
48 weeks
Notes

Research doses: 25-100 mcg/kg intranasal/IV. Bodybuilding: 100-300mcg SC before bed. Very short plasma half-life (~7-25 min, estimates vary) but biological effects persist. Phosphorylated DSIP (DSIP-P) may have extended half-life.

Half-Life

Plasma clearance is very fast (rapidly degraded by peptidases; estimates vary by source), but behavioral/sleep effects have been reported to persist for hours, up to ~20 hours after IV dosing in one human study (Schneider-Helmert & Schoenenberger 1983).

Side Effects

Transient Warmth/Flushing

common
Severity
1/5

Brief sensation of warmth after injection.

Mitigation

Self-limiting. No intervention needed.

Drowsiness

common
Severity
1/5

Expected effect - indicates activity. Take before bed.

Mitigation

Ensure administration before bedtime.

Mild Headache

uncommon
Severity
1/5

Occasional headache reported.

Mitigation

Usually transient. Stay hydrated.

Injection Site Reaction

uncommon
Severity
1/5

Mild irritation at injection site.

Mitigation

Rotate injection sites.

Transient Hypotension

rare
Severity
1.5/5

Brief blood pressure reduction reported rarely.

Mitigation

Lie down if dizzy. Usually resolves quickly.

General Mitigation Strategies

DSIP is generally well-tolerated. The largest human trial to date (Dick et al. 1984, n=107, IV dosing for withdrawal syndromes) reported good tolerance aside from headaches in a few patients, with no serious adverse events. Side effects at typical research doses are typically mild and transient. No significant cardiovascular concerns reported at research doses. Long-term safety data is limited. No evidence of dependence or tolerance in short-term use.

Support Supplements

Ancillary supplements commonly run alongside DSIP to manage side effects, support the target tissue, or fill nutrient demands it creates.

Magnesium (glycinate/threonate)

Well-tolerated sleep-quality aid that complements a sleep-focused peptide, supports GABAergic tone and muscle relaxation. Deficiency is common in hard-training lifters.

Dose
~200-400mg elemental
Timing
Evening, with the pre-bed DSIP dose
When
General sleep support rather than a DSIP-specific requirement.

Glycine

Amino acid shown to improve subjective sleep quality and lower core body temperature at sleep onset; pairs logically with a slow-wave-sleep peptide.

Dose
~3g
Timing
30-60 min before bed
When
Optional add-on; modest, evidence-backed effect on sleep onset.

Post Cycle Therapy (PCT)

PCT Not Required

Does not suppress the HPT axis. No PCT required. May indirectly support recovery through improved sleep quality (direct cortisol-normalizing effects have not been confirmed in controlled human trials).

How It Works

Incompletely understood. Modulates GABA-A receptor activity (possibly allosteric). Influences serotonin release and 5-HT receptor sensitivity. Promotes delta wave sleep without significantly altering REM. Stimulated GH release during sleep phases and blunted stress-hormone responses in animal models, but controlled human trials found no effect on GH/prolactin or on CRH-/meal-induced ACTH/cortisol secretion. Crosses blood-brain barrier despite peptide nature.

Fundamentals

Common Stacks

  • DSIP 100-200mcg before bed + Ipamorelin/Mod GRF - sleep and GH optimization
  • DSIP + Melatonin - enhanced sleep quality (start melatonin low)
  • DSIP during contest prep - sleep support during stressful deficit
  • Avoid CNS depressants (benzos, alcohol, opioids) - additive sedation risk
  • Take 30-60 minutes before intended sleep time

WADA Status

WADA Status Unclear

DSIP (Delta Sleep-Inducing Peptide) is not explicitly listed on the WADA Prohibited List. It has no direct performance-enhancing effect, but as a non-approved research peptide it could still be argued under S0 (non-approved substances) for tested athletes, so its status is genuinely unclear. Verify before competition.

References

Last updated: July 19, 2026