Selank Protocol: Concentrations Behind the Schedule

The compound reaches buyers in two forms: a vial of lyophilised powder to be reconstituted, and a nasal spray. Both end at a delivered mass, and they get there through different intermediate quantities.

The common structure is worth stating once. A container holds a labelled mass in a liquid volume, which fixes a concentration. A delivery device removes a fixed volume. The mass delivered is the concentration multiplied by that volume. Every disagreement about amounts on this compound is a disagreement about one of those three inputs, usually an unstated one.

What differs between the branches is which input is under the buyer's control and which is a property of a device.

The vial arrives dry. Nothing in it corresponds to a volume until bacteriostatic water is added, and the volume added is a free choice.

Concentration is labelled mass divided by added volume. A 5 mg vial with 2.5 mL gives 5 divided by 2.5, which is 2 mg per mL. The same vial with 1 mL gives 5 mg per mL, and with 5 mL gives 1 mg per mL.

Mass drawn is concentration multiplied by volume drawn. A U-100 insulin syringe fills 1 mL at 100 units, so one unit is 0.01 mL. At 2 mg per mL, ten units are 0.1 mL and hold 2 times 0.1, which is 0.2 mg, or 200 mcg.

Working the other way, from a target mass to a reading: volume needed is target mass divided by concentration. For 300 mcg at 2 mg per mL, that is 0.3 divided by 2, which is 0.15 mL, or 15 units. At 1 mg per mL it is 0.3 mL, or 30 units, which is most of a small syringe.

The spray removes one choice from the buyer and adds one to the manufacturer.

If the bottle came pre-filled, the concentration is set by whoever filled it: a 5 mg bottle at 5 mL is 1 mg per mL. If the buyer reconstituted a vial and transferred the liquid, the concentration is theirs to compute, minus whatever was left behind in the vial and the transfer syringe.

Either way the delivered volume belongs to the pump. Nasal pumps are built to release a fixed volume per stroke, and different pumps are built to different volumes. That figure has to come from the hardware specification. At 1 mg per mL, a pump delivering 0.1 mL carries 1 times 0.1, which is 0.1 mg, or 100 mcg. The same bottle with a pump delivering 0.05 mL carries 50 mcg.

There is no equivalent of reading a barrel here. A pump gives no feedback about what it delivered, which makes the specification the only source of the number.

Volume is what an instruction actually names. Mass depends on a concentration the instruction usually omits.

Row three is the one that catches people. A U-40 barrel makes one unit 0.025 mL, so the same printed reading is two and a half times the volume of the U-100 case, before anything about the contents is considered.

Every quantity above is easy to compute and impossible to recover later if the inputs went unwritten. Six entries make a preparation reproducible: the labelled mass, the liquid volume, the concentration derived from dividing one by the other, the device and its scale or rating, the delivered volume, and the mass that follows.

Three of those are recorded facts and three are derived. The derived ones cost nothing to write down and cannot be reconstructed by looking at a filled syringe or a half-empty bottle. An unrecorded fill volume turns every microgram figure from that container into an assertion.

Measurement error deserves a line too. Diluent is usually drawn with the same syringe that will later draw from the vial, and an overshoot propagates. Intending 2.5 mL and adding 2.7 mL turns 5 divided by 2.5 into 5 divided by 2.7, so the concentration is 1.85 mg per mL rather than 2, and a 0.1 mL draw holds 185 mcg instead of 200. The barrel reads 10 units either way.

Yield belongs in the same record, because it is the check that a plan fits the container at all. A 5 mg vial drawn 200 mcg at a time gives 5 divided by 0.2, which is 25 withdrawals. A 5 mL bottle at 0.1 mL per actuation gives 50 nominal actuations, fewer once priming strokes and the liquid the dip tube cannot reach are subtracted. Writing the yield next to the concentration turns an abstract schedule into a count of containers.

Selank is a synthetic heptapeptide derived from the endogenous peptide tuftsin, developed in Russia and studied mainly as an anxiolytic. It is registered as a medicine in Russia, and the clinical literature produced in humans within that system is real work that should not be dismissed.

It also holds no authorisation from the FDA, the EMA or the MHRA, and there is no genuine registered Western trial. Searching a Western registry by name returns records that match the text and turn out to be studies of unrelated interventions, so no trial identifier appears anywhere on this page. Animal work in rats and mice exists and reports amounts per kilogram of animal body weight.

The gap that matters for a protocol is narrower than either summary suggests. Even the Russian record describes a manufactured medicine used under clinical supervision, not a research chemical vial reconstituted at a kitchen table. Those are different products with the same name.

No amount for a person, no frequency, no duration and no starting point appears here. The reason is that the arithmetic cannot produce one and nothing else on the record can supply it either.

Division moves between mass, volume and graduations. It has no access to clearance, to route differences between an injection and a nasal membrane, or to a safety margin, and it will happily generate a confident number from any inputs it is handed. That is precisely why its output must not be dressed up as a recommendation. A schedule copied from a forum has the same defect with an extra layer of confidence on top.