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No human trialsNot FDA approved

N-Acetyl Semax Amidate

Also known as: NA-Semax Amidate · NA-Semax-Amidate · NASA · N-Acetyl-Semax-Amidate Acetate · Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2 · Ac-MEHFPGP-NH2

Updated 42 sources

Semax with two chemical caps: an acetyl group on the front of the chain and an amide on the back (Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2). Vendors and dosing guides say the caps slow breakdown, so it hits harder and lasts longer than Semax, often quoting 2 to 3 times the potency. Nobody has measured that, and no published study has dosed a person or an animal with it. People take it for focus and drive by nasal spray or under the skin.
Calculate with N-Acetyl Semax AmidateDosage chart

Quick facts

Half-life
  • Not measured. One guide estimates about 30 to 45 minutes, longer than Semax.
  • Not measured. Other guides claim several hours, or 2 to 10 hours vs 0.5 to 2 for Semax.
Routes
  • Nasal
  • Subcutaneous injection
Forms
  • Nasal spray
  • Vial (powder)
Reported dose ranges
  • 200 to 1,200 mcg (nasal)
  • 200 to 1,000 mcg (subcutaneous injection)
Vial sizes
  • 30 mg
Chemistry
  • 855 g/mol · C39H54N10O10S · CAS 2920938-90-3
FDA status
  • Not FDA approved
WADA
  • Not confirmed

What people use N-Acetyl Semax Amidate for

  • Focus and drive for work or study, the main use in Reddit threads
  • Calmer focus on days off ADHD stimulants, as several users describe
  • A stronger per-mcg Semax, which is how vendors and guides pitch it
  • Anxiety, usually paired with N-acetyl Selank amidate

How it is thought to work. No study has tested how this exact molecule works. Guides assume it acts like Semax, which raises BDNF and shifts dopamine and serotonin in rodents, with the two caps slowing the enzymes that chew peptides from each end. The only lab work on an acetylated Semax found the acetyl cap changed how it binds copper and removed Semax's protection of nerve cells against copper toxicity. A 2013 Russian paper measured how acetyl-Semax resists breakdown; its abstract is not public.

N-Acetyl Semax Amidate dosing

9 protocols from studies, guides and community reports, grouped by goal. Tap a source badge to see where a number came from.

Nasal, nasal spray6

Nasal start (daily total, guide)

Amount
600 mcg
How often
Daily total, adjusted to response
Route
Nasal, nasal spray
Cycle
Up to 60 days at 600 mcg a day; no more than 30 days at 900 mcg a day or higher
Rest
A washout as long as the run
Timing and details

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Nasal (daily total, guide)

Amount
200 to 1,200 mcg
How often
Daily total, split into 1 to 2 doses
Route
Nasal, nasal spray
Cycle
14 to 30 days
Timing and details

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Nasal per dose (guide)

Amount
200 to 600 mcg
How often
1 to 2 times a day
Route
Nasal, nasal spray
Cycle
5 days on and 2 off, or 3 to 4 weeks on
Rest
1 week off after a 3 to 4 week run
Timing and details

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High nasal per dose (guide)

Amount
600 to 1,200 mcg
How often
1 to 2 times a day
Route
Nasal, nasal spray
Cycle
10 to 30 days
Timing and details

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Daily nasal (community)

Amount
200 to 600 mcg
How often
Once in the morning, sometimes again in the early afternoon
Route
Nasal, nasal spray
Timing and details

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Spray count, a few days a week (community)

Amount
200 to 400 mcg
How often
A few times a week, 2 sprays, or 4 for a second dose early afternoon
Route
Nasal, nasal spray
Timing and details

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Injected3

Subcutaneous (daily total, guide)

Amount
500 to 1,000 mcg
How often
Once daily
Route
SubQ, vial (powder)
Cycle
Up to 30 days at 1,000 mcg a day, or up to 60 days at 500 mcg a day
Rest
A rest as long as the run
Timing and details

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Subcutaneous per dose (guide)

Amount
200 to 600 mcg
How often
1 to 2 times a day
Route
SubQ, vial (powder)
Timing and details

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Cautious subcutaneous start (community)

Amount
200 mcg
How often
Once daily
Route
SubQ, vial (powder)
Timing and details

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Doses shown are what sources report, labelled by origin. Not medical advice.

Full N-Acetyl Semax Amidate dosage guideEvery titration step in syringe units, missed doses and how to mix.
Calculate with this peptideYour vial, your water, your dose: N-Acetyl Semax Amidate in syringe units, with the math shown.

N-Acetyl Semax Amidate side effects

What trials and labels report, kept apart from what users and guides report. Frequencies are worded as each source states them.

Reported by users and guides6

From community reports and dosing guides. Not measured rates.

  • Worse sleep or insomnia

    Reported by individual users; one guide lists sleep disruption when NA-Semax is taken later in the day

    How people manage it

    • Dose in the morning or early afternoon, as guides and users advise

  • Crash, headache and low mood as it wears off

    One detailed r/Nootropics report; a guide lists tiredness as effects fade

    How people manage it

    • The user advises people in recovery from stimulant use to avoid it

  • Anxiety, overstimulation or irritability

    Reported by some users; a guide lists overstimulation and irritability

    How people manage it

    • Lower the dose

  • Headache

    Occasional per guides, more often at higher doses; mentioned by users

    How people manage it

    • Lower the dose

  • Nasal or throat irritation, runny nose

    Common and mild with sprays, per guides; extrapolated from Semax

    How people manage it

    • Alternate nostrils

  • Brain fog

    Reported by individual users

    How people manage it

    • Lower the dose or stop
All 12 N-Acetyl Semax Amidate side effects and how people manage themEvery management tip, who should not use it, and side-effect questions.

Who should avoid it

  • Stimulants and other CNS-active drugsSubstance

    No interaction data exist for this variant. Guides advise against combining it with other nootropics or stimulants.

  • Pregnancy and breastfeedingCondition

    No reproductive or developmental safety data for this variant.

  • Mania or bipolar-spectrum instabilityCondition

    One guide urges caution because Semax-type peptides shift dopamine and may aggravate activation.

  • Anxiety disordersCondition

    The Russian label for plain Semax lists anxiety disorders as a contraindication. No label exists for this variant, and some users report anxiety on it.

Storage

Powder (before mixing)

Temperature
-80 to -20 °C

Freezer at -20 C long term. One chemical supplier gives 1 year at -20 C and 2 years at -80 C for the sealed powder.

Mixed vial

Temperature
2 to 8 °C
Use within
14 to 21 days

Fridge at 2 to 8 C, use within 14 to 21 days.

As supplied

Temperature
2 to 8 °C

Premixed sprays: keep in the fridge at 36 to 46 F (2 to 8 C).

Mixed with: Bacteriostatic water for injection; sterile saline for nasal sprays

Mixing. No source gives a tested water volume for this peptide. One guide mixes the powder with sterile saline to a 0.1% or 0.3% solution for a spray. Pump volumes vary, so calibrate a homemade spray on a known volume.

Stacks people report

Combinations from guides and community posts, with the reason given.
  • N-Acetyl Selank Amidate

    The usual partner: the amidate for drive in the day, N-acetyl Selank amidate for calm, or one spray of each together. Premixed blends of the two are sold. Many users still try each alone first.

  • Selank

    Guides pair it with plain Selank the same way Semax is paired: focus from one, calm from the other.

Related versions

  • Semax

    Semax with an acetyl cap on the front and an amide cap on the back. Vendors and guides claim it is more stable and 2 to 3 times stronger per mcg; no study has measured either. In one lab study, acetylation removed Semax's cell protection against copper.

  • Adamax

    Adamax replaces the amide cap with an adamantyl-glycine cap. Both are sold as research chemicals with no published human data.

Compare N-Acetyl Semax Amidate

Evidence and legal status

Evidence: no human trials

No human or animal study of this molecule exists. Two lab papers looked at acetyl-Semax: one found the acetyl cap changed copper binding and removed cell protection, and one measured resistance to breakdown (abstract not public). Every benefit quoted for it comes from Semax research. A chemical supplier and a drug company patent list it as a Semax derivative.

FDA and WADA

Not FDA approved

No approval, no trial program and not on FDA's compounding lists.

Not FDA approved and not named by FDA. FDA lists plain Semax among compounding substances nominated and then withdrawn, and its 2026 Semax review warns that salts and derivatives, including different active molecules, are sold under the same common name.

No approval in any country was found; one guide says it has not had extensive clinical study anywhere and is sold as a research chemical. Plain Semax is a Russian prescription drug; we found no registration of the amidate anywhere. WADA's 2026 List names neither Semax nor this amidate. Only the S0 catch-all for substances without human approval could apply, so we mark it unknown.

WADA: Not confirmed

N-Acetyl Semax Amidate questions

What is N-acetyl Semax amidate?

Semax, the Russian nasal nootropic, with two caps added: an acetyl group on the front of the chain and an amide on the back. The full name in peptide shorthand is Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2. It is sold as a research chemical in vials and premixed sprays.

Is it stronger than regular Semax?

Guides say 2 to 3 times stronger per mcg, and one says its effect lasts 2 to 4 times longer, while flagging that as a vendor and community claim. No study has compared the two. Users split: some say the amidate is stronger, others say it lasts longer with equal or less punch.

How much do people take?

Guides run from 200 to 1,200 mcg a day by nasal spray and 500 to 1,000 mcg a day under the skin. Users on Reddit mostly report 200 to 600 mcg in the morning. There is no label or trial dose for this variant.

Should the dose be lower than Semax?

Guides contradict each other. One says cut doses because of the potency claim and start at 100 to 200 mcg. Another starts at 600 mcg a day, the same scale as plain Semax. With no data either way, the one Reddit reply we found on this suggests starting lower, at 200 mcg.

What is its half-life?

Nobody has measured it. Guide estimates range from about 30 to 45 minutes to 2 to 10 hours, which tells you they are guesses. Plain Semax is broken down within minutes in rats.

Is N-acetyl Semax the same as N-acetyl Semax amidate?

No. N-acetyl Semax has only the front cap and keeps a free acid at the back end. The amidate has both caps. Vendors sell them as separate products, and Reddit often uses "NA-Semax" for either, so read the label.

Nasal spray or injection?

Both. Guides give nasal and subcutaneous the same or similar ranges. Premixed sprays are common, at 100 mcg per spray on one product users describe.

What side effects do people report?

Worse sleep, a crash with headache and low mood as it wears off, anxiety or brain fog, and sleepiness at higher doses come up in threads. Guides add nasal irritation and occasional headaches. None of this comes from a study.

When should I take it?

Morning or early afternoon. Guides warn it can be too stimulating near bedtime, and users report worse sleep.

How should it be stored?

Powder in the freezer at -20 C. Once mixed, keep it at 2 to 8 C and use it within 14 to 21 days. Keep premixed sprays in the fridge.

Can I take it with N-acetyl Selank amidate?

It is a common pairing: the Semax version for drive, the Selank version for calm. Some users spray one in each nostril, and premixed blends of the two are sold.

Who came up with it?

No paper describes its design. Reddit users credit a US nootropic vendor, now closed, with first selling it. A drug company patent on Semax nasal formulas later listed the amidate among possible derivatives, and a chemical supplier now sells it citing that patent.

Is it the same as Adamax?

No. Adamax caps the back end with an adamantyl-glycine group instead of a plain amide. Both are sold as research chemicals without human data.

How long until it works?

Users differ. Some describe effects within about 30 minutes of a nasal dose; one felt nothing over 3 days at 100 to 400 mcg.

Ask about N-Acetyl Semax Amidate

Answers come from this site's pages only, with a link to each source.

Sources

42 sources, each checked by date. Record updated Oct 24, 2026. Numbers are restated in our own words and labelled by where they came from.

Reference work2

  1. N-acetyl semax amidate (CID 172638603)PubChem · checked Oct 24, 2026
  2. WO2023046336A1: Adrenocorticotropic hormone peptide compositions and methods of useGoogle Patents (Ferring B.V.) · checked Oct 24, 2026

Vendor guide2

  1. N-Acetyl semax amidate product data sheet (HY-P3588)MedChemExpress · checked Oct 24, 2026
  2. N-Acetyl Semaxlimitlesslifenootropics.com · checked Oct 24, 2026

Competitor guide7

  1. N-Acetyl Semax Amidatepeptides.org · checked Oct 24, 2026
  2. NA-Semax Amidatebodyhackguide.co · checked Oct 24, 2026
  3. NA-Semax Amidatepeptidedeck.com · checked Oct 24, 2026

Community-reported24

  1. r/Peptides: How to reconstitute Selank and Semax 30mgr/Peptides · checked Oct 24, 2026
  2. r/Nootropics: Difference between N-Acetyl Semax Amidate and regular semax (comment)r/Nootropics · checked Oct 24, 2026
  3. r/Peptides: N-Acetyl Semax Amidate (comment)r/Peptides · checked Oct 24, 2026