Skip to content

Anti-aging & longevity

Semax / Selank

Semax and Selank blend · cognitive blend · Semax Selank

PreclinicalReviewed 25 Aug 2026

What is in the vial

Components of Semax / Selank and their share of a standard vial.
CompoundPer vialShare
SemaxACTH-fragment analogue. The attention and recovery half.10 mg50%
SelankTuftsin analogue. The anxiolytic half.10 mg50%

The ratio is fixed in the vial. Choosing a dose of one component chooses the dose of all the others — you cannot move one without moving them all.

What the contents cost separately

The same masses this vial holds, bought as individual vials, at the cheapest confirmed listing and at the median across vendors. We do not price blend vials themselves — hold this against whatever you are being quoted.

$59$72

for 20 mg across 2 compounds

Cost of each component bought separately
CompoundIn this vialSeparately
Semax10 mg$31–$35
Selank10 mg$28–$37

Buying separately costs more injections and more vials, and buys back the ability to change one dose without changing the others. Prices are read from vendor sites and normalised per milligram; we take no vendor placement. Every listing.

The one nootropic blend that genuinely ships pre-mixed, commonly as a 20 mg vial with 10 mg of each. Semax and Selank are frequently discussed together and are sold together for that reason.

They are not the same kind of compound. Semax is derived from an ACTH fragment and is discussed for attention and recovery; Selank is a modified tuftsin analogue discussed for anxiety. Combining them targets two different things at once, which is a reason to want them separate rather than fixed in one vial.

Both carry the same underlying evidence problem: the human literature is largely Russian, largely from the institutes that developed them, and has not been independently replicated. That is a statement about corroboration rather than about plausibility.

How it works

Two mechanisms arriving together, not studied as a mixture.

Semax is a fragment analogue of ACTH(4-10), discussed in terms of BDNF expression and attention in Russian clinical literature.

Selank is a synthetic analogue of tuftsin, discussed as an anxiolytic without the sedation of benzodiazepines.

Neither mechanism has been established in independently replicated human work.

Regulatory status — United States

Not approved in the United States as a mixture or as either of its parts. Both components are registered medicines in Russia.

Last reviewed 25 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.

What it is studied for

Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.

Attention, mood and stress

Published review

What the combination is sold for.

EvidenceBoth components have Russian clinical literature that has not been independently replicated. The mixture has not been studied at all.

Identity and clearance

Molecule

Class
Pre-mixed blend of two neuropeptides, 1:1 by mass

A 20 mg vial is 10 mg of each.

Dose protocols reported in sources

Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.

Dose protocols reported in sources, with the source of each.
GoalDoseFrequencyRouteUnits, 20 mg vialSourceStart this protocol
Commonly described community protocol300 mcg – 600 mcgOnce or twice daily, in courses of 2 to 4 weeksNasalTotal blend. At 1:1, 300 mcg of blend delivers 150 mcg of each component. Intranasal is the common route for both components separately.1.5–3 uCommunity practiceStart this

Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.

CheckRows marked community practice describe what people commonly do, drawn from public discussion. They are not derived from any trial and are not evidence that a dose is safe or effective.

Calculator

Work out what to draw

Pre-filled with a 20 mg vial as a worked example. These are not recommended values — change them to match the vial in front of you.

Dose unit
Your syringe
01020304050607080901003 units0.03 mL

Draw to 3 units on a 1 mL U-100 syringe. That is 0.03 mL, containing 300 mcg of Semax / Selank.

Concentration10mg / mL
Volume drawn0.03mL
Doses per vial66.7doses
Per unit100mcg / unit

Check3 units falls between the printed lines on a 1 mL U-100 syringe. Mixing with 4 mL of water instead would put this dose at 6 units.

Bioalmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.

Open this calculation in the full calculator

Units, concentration, bacteriostatic water — the glossary defines the vocabulary, and a unit is not a fixed volume.

Safety

Reported effects

  • Everything from two compounds at oncePublished review

    Unknown

    No human study of the mixture. Each component's own adverse-effect profile applies, and they cannot be separated if something goes wrong.

  • Injection site reactionsCommunity practice

    Commonly reported

  • Nasal irritationCommunity practice

    Commonly reported

    The usual route for both components is intranasal.

When to stop

  • Any allergic response: rash, hives, facial swelling or difficulty breathing. Seek urgent care.
  • New or worsening anxiety, agitation or sleep disturbance.
  • Persistent headache, which is the effect most commonly reported with Semax.
  • Nasal pain, bleeding or a sense of obstruction that does not settle between doses.

Interactions and situations that need care

  • Pregnancy and breastfeedingAvoid

    No safety data for either component, let alone the mixture.

  • Wanting to control the dose of one componentUse caution

    Two compounds at a fixed ratio means Two doses chosen at once. Running them separately is the only way to dose them separately.

  • Taking psychiatric medicationUse caution

    Both components are discussed as acting on mood and attention, and neither has been studied alongside psychiatric medicines.

What to expect

HonestlyThere is no human efficacy data for this compound, so there is no evidence-based timeline to give. Any site publishing a week-by-week schedule of expected effects has invented it.

  • No study of the mixture. Both components rest on unreplicated Russian literature.
  • They target different things — attention and anxiety — which is an argument for dosing them separately.
  • Fixed 1:1 ratio, so you cannot raise one without the other.
  • Commonly used intranasally rather than injected.

Storage and handling

Freeze-dried powder
Refrigerated at 2–8 °C, protected from light.
After mixing
Refrigerated at 2–8 °C and used within about 30 days. A blend cannot be split. A contaminated vial takes every component with it.
Long-term, frozen
Unopened powder is stable at −20 °C or colder.

Printable one-pagerHow to reconstitute a vial, step by step

Checking your vial

Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.

  • Clear and colourless after reconstitution

    Nothing here is coloured. A tinted solution is not this blend.

  • Cloudiness or visible particles

    Discard it.

Questions

Is this the same as the cognitive stack with Dihexa?
No. Semax with Selank is a blend that genuinely ships in one vial. A three-way with Dihexa is a stack somebody assembled from separate vials — we could not find it sold pre-mixed.
Injected or intranasal?
Both components are commonly used intranasally, and the blend is usually described that way. Some vendors list it for subcutaneous use. The route changes the dose, and neither has been established for the mixture.

References

  1. Component evidence for common peptide blends: an assessment of what is known separately

    Preclinical peptide literature, 2024 · Assessment of the separate component literatures

    Cell culture and rodent models

    Every component of the common blends is supported by animal or cell-culture work only. No study has examined any of these combinations as a mixture, so combination evidence is weaker than the single-compound evidence. That is itself preclinical.

  2. Community and vendor practice, unverified

    Vendor listings and community protocols, 2026 · Anecdote

    Self-selected, unverified

    Ratios and doses as vendors sell and users describe them. Ratios vary between sellers, so a blend bought from two vendors is not necessarily the same product.

Keep this page honest

If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.

Suggest a correction

This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.

Page last updated 25 Aug 2026