Head to head

DSIP vs Selank

Nootropic

Two compounds that are more often stacked than compared — the side-by-side data, and what actually separates them.

Verdict

Usually stacked — and Selank rests on firmer evidence

DSIP and Selank appear in each other's stacks in this dataset, so the most common real-world use is together rather than instead of. If you are picking one, the evidence is the honest tiebreak: Selank has approval from a regulator somewhere, though not a current FDA or EMA label, while DSIP has some human data, but it is small, old, or uncontrolled. That is a difference in how much is known, not a verdict on how well either works.

What you are actually choosing between

Before anything else: the dataset lists DSIP and Selank in each other's stacks. They are run together more often than they are chosen between, so if you came here for a winner, the first honest answer is that this may not be an either/or.

Both are classed here as nootropics, so this is a within-class choice: the mechanism is broadly shared and what separates them is kinetics, route, and how much has actually been tested.

The overlap is recovery and sleep. On this site's goal weighting — an editorial priority score, not a measure of effect size — DSIP rates 4/5 for recovery and sleep and Selank rates 4/5. Outside that overlap only Selank goes further, carrying weight for focus and cognition; DSIP's declared goals stop at the overlap.

The evidence

This is the part that decides most of it. Selank has approval from a regulator somewhere, though not a current FDA or EMA label — a registered Russian medicine; the trials are small and Russian-language. DSIP has some human data, but it is small, old, or uncontrolled — the controlled work is a handful of small studies from decades ago. That gap is the headline, and it is a statement about the literature rather than a promise about you: a compound with trial data can still do nothing for your case, and one without it is unproven rather than disproven.

How they differ in practice

DSIP is a subcutaneous injection and an intramuscular injection; Selank is a nasal spray and a subcutaneous injection. That is the difference most people actually feel: DSIP means reconstituting a vial and injecting; Selank does not require either. If needles are the deciding factor, this line settles it before any of the rest matters.

No half-life is published for either compound in this dataset. That absence is itself information: it means the pharmacokinetics have not been characterized well enough to quote, so both dosing schedules — once daily for DSIP, twice daily for Selank — are convention.

Committed time differs: DSIP runs 4 weeks, Selank runs 2 weeks.

Source notes

What the evidence actually says

Verbatim, so you can check the verdict above against what it was built from.

DSIP (Delta Sleep-Inducing Peptide)

DSIP is a nine-amino-acid peptide isolated in the 1970s by Monnier, Schoenenberger and colleagues from the cerebral venous blood of rabbits in electrically induced delta-wave sleep, which is where the name comes from. It is not approved anywhere and has no modern development program. The human evidence is old, small and sparse, and it does not show what the name implies. The controlled work is a handful of studies from roughly 1977 to the early 1990s, mostly with a few dozen subjects at most, and the effects on sleep architecture were modest and inconsistent between groups. Some of the more repeatable findings were not in insomnia at all but in chronic pain and in opiate and alcohol withdrawal. DSIP is not a sedative and does not behave like one: it does not reliably knock anyone out, and whether an injected dose crosses the blood-brain barrier intact in meaningful quantity is still disputed. Treat any claim of a strong hypnotic effect as unsupported. On dosing, the classic human studies gave roughly 25 nmol/kg intravenously - about 1.5 mg for a 70 kg adult - which is both a different route and a much larger amount than anyone injects subcutaneously today. That figure has deliberately NOT been used to set the ceiling here. The 100-500 mcg subcutaneous range with a typical dose around 200 mcg reflects contemporary community practice, taken shortly before bed; there is no trial behind that range, and no dose-response curve exists for this route. Plasma half-life is reported in minutes, so no hourly figure is listed. The four-week cycle length is convention rather than evidence - no study has run long enough to establish a course length, and nothing is known about tolerance or long-term use.

Selank

A synthetic heptapeptide analogue of the immune peptide tuftsin, again with a Pro-Gly-Pro tail added for stability. Its character is anxiolytic rather than stimulant, which is why it is usually paired with, not substituted for, Semax. Like Semax it is a Russian-registered intranasal medicine (commonly a 0.15% solution) and is NOT approved in the US or EU; the human evidence is small Russian trials in generalised anxiety disorder and adjustment disorder, some comparing it against benzodiazepines such as phenazepam, and it has not been independently replicated in Western trials. Route matters: it is an intranasal drug, not an injectable. Russian clinical dosing runs to roughly 1800-2700 mcg per day divided across two or three administrations; the per-dose range here reflects the more conservative doses typical of non-clinical use rather than the full trial daily total. Plasma half-life is minutes, so no hourly figure is listed. Courses are conventionally short (10-14 days) rather than continuous.

Side by side

The numbers

DSIP compared with Selank
Attribute	DSIP	Selank
Class	Nootropic	Nootropic
Routes	Subcutaneous, Intramuscular	Intranasal, Subcutaneous
Dose range	100 mcg–500 mcg (typical 200 mcg)	150 mcg–900 mcg (typical 300 mcg)
Frequency	Once daily	Twice daily
Half-life	Not characterized	Not characterized
Cycle length	4 weeks	2 weeks
Experience	Intermediate	Intermediate
Evidence	Limited human data	Approved elsewhere
Contraindications	Pregnant / nursing Under 18	Pregnant / nursing Under 18
Side effects	Injection site stinging or redness Morning grogginess or a hungover, heavy feeling on waking Vivid or unusually intense dreams Headache Dizziness or a brief drop in blood pressure shortly after injecting Paradoxical alerting - a minority of users report harder, not easier, sleep onset Transient flu-like malaise in the first few doses	Nasal stinging or irritation at the spray site Drowsiness or blunted drive, more likely at the top of the range Mild headache Bitter taste or post-nasal drip after spraying

Turn a typical dose into a mark on the syringe: DSIPSelank

Goals

Where they overlap, and where they do not

Goal	DSIP	Selank
recovery and sleep	DSIP: 4/5	Selank: 4/5
focus and cognitionone only	DSIP: —	Selank: 3/5
immune supportone only	DSIP: —	Selank: 2/5
neuroprotectionone only	DSIP: —	Selank: 2/5

They overlap on 1 goal and diverge on 3. Weights are this site’s editorial priority score out of 5 — how central a goal is to why people use a compound. They are not effect sizes and two 5s do not mean two equal results.

Go deeper

MonographDSIP (Delta Sleep-Inducing Peptide)Mechanism, protocol, storage, sources.MonographSelankMechanism, protocol, storage, sources.ToolReconstitution calculatorTurn either dose above into a mark on the syringe.

Other comparisons with these two

Educational information only, not medical advice. Talk to a licensed clinician before starting, changing, or stopping anything.