Both are sold for sleep or calm and both come out of the same Soviet-era and Swiss research traditions. DSIP is the more extreme case: fifty years on, nobody established what it acts through.
Side by side
| DSIP | Selank | |
|---|---|---|
| Class | Sleep-associated nonapeptide | Anxiolytic heptapeptide |
| Status | Research compound | Approved in Russia (intranasal); research compound elsewhere |
| Route | Subcutaneous injection | Intranasal (primary) or subcutaneous |
| Typical vials | 2 mg, 5 mg | 5 mg, 10 mg |
| Dose range | 100 mcg to 500 mcg | 250 mcg to 750 mcg |
| Frequency | Nightly, before bed | Daily, as needed |
| Half-life | No human data | No human data |
| Dosing unit | micrograms | micrograms |
Pharmacokinetics
No curves are shown, on purpose.
No published human pharmacokinetics for DSIP or Selank. Drawing one curve against an absent one would imply a comparison that cannot be made.
What the evidence supports
These grade how well each outcome has been studied in humans, never how well either compound works. A strong grade can sit on a negative result.
The strongest evidence for any claimed outcome is Human RCT for Selank and Human, observational for DSIP. That gap is the most important line on this page.
DSIP
| Outcome | Evidence |
|---|---|
| Chronic pain | Human, observational |
| Sleep onset in insomnia | Human, observational |
| Modern replication of any 1980s result | No data |
Selank
| Outcome | Evidence |
|---|---|
| Generalized anxiety disorder | Human RCT |
| Cognitive and attention measures | Human, observational |
| Independent replication outside Russian literature | No data |
How to choose
DSIP's mechanism was never elucidated
Despite the name, it is not a straightforward sedative, no receptor or pathway was ever pinned down, and research largely stopped in the 1990s.
Selank at least has a proposed mechanism and recent trials
GABAergic and monoamine systems, with Russian clinical work.
Neither has evidence a reader outside Russia can easily check
For DSIP the literature is old and thin; for Selank it is Russian-language and not replicated.
At the syringe
At the default setup on each compound's own page, a 5 mg vial in 2 mL puts 25 mcg on every insulin unit, while a 5 mg vial in 2 mL puts 25 mcg on every unit. That is the number that decides whether a dose lands on a readable mark, and it is set by how much water goes in, not by the compound.