Semax Dosage: The Doses Researchers Actually Used

Every Semax dosage chart online looks confident. Almost none of them tell you where the numbers come from.

These are the doses that appear in the published studies. They describe what researchers did. They are not a recommendation, and Semax is not an approved drug outside Russia.

Doses used in human studies

• Acute ischemic stroke: 12 mg a day for moderate strokes and 18 mg a day for severe ones, for 5 to 10 days, on top of standard intensive care. (Gusev 1997)
• Stroke rehabilitation: 6,000 micrograms (6 mg) a day for 10 days, then a 20-day break, then a second 10-day course. (Gusev 2018)
• Stubborn peptic ulcers: a 1% nasal solution, 2 to 4 drops three times a day for 10 days, added to the usual ulcer drugs. (Ivanikov 2002)
• Memory and attention in healthy people: 0.015 to 0.050 mg per kg of body weight into the nose. For a 75 kg person that is roughly 1 to 4 mg. The developers describe the effect as lasting 20 to 24 hours. (Ashmarin 1997)
• Brain-imaging study in healthy volunteers: a single dose of 1% nasal solution, with changes on the scan at 5 and 20 minutes. (Lebedeva 2018)

Notice the pattern. The hospital doses for stroke are several times higher than the doses used for cognition, and every course is short: days, not months.

Nasal or injection?

The human studies above used the nasal route.

In rats, researchers compared the two directly. Given into the nose, Semax improved learning more than the same peptide given by injection into the abdomen. The injection reduced pain sensitivity and the nasal route did not. (Manchenko 2010)

So the route changes what it does, at least in rats. I found no human study of subcutaneous Semax, which means the injection charts online are not based on clinical research. I will not give instructions for injecting or mixing a research chemical.

How often and how long

• The clinical courses lasted 5 to 10 days.
• The rehabilitation protocol repeated a 10-day course after a 20-day break.
• No study describes continuous daily use for months.

What the charts leave out

• There is no published human half-life.
• The modified versions sold online, such as N-acetyl Semax amidate, are not the compound used in these studies, so these doses do not transfer to them.
• Research-chemical vials are not checked for purity or for the amount on the label.
• In brain-injured patients, the first dose sometimes produced seizure-like EEG activity. See Semax side effects.

The rest of the evidence is in the Semax guide.

Quick answers

What is the dosage of Semax?

Published studies used 6 to 18 mg a day into the nose for stroke, for 5 to 10 days, and about 0.015 to 0.050 mg per kg for memory and attention in healthy people. These are research doses, not medical advice.

How often is Semax taken?

In the ulcer study the nasal solution was given three times a day for 10 days. Stroke courses lasted 5 to 10 days. No study covers months of daily use.

Can Semax be injected?

The human studies used the nasal route. In rats the nasal route improved learning more than injection did. I found no human study of subcutaneous Semax.

What is the half-life of Semax?

There is no PubMed abstract with human pharmacokinetic data. Its developers describe effects lasting 20 to 24 hours after a nasal dose.