Cognitive & Nootropic

N-Acetyl Semax

Ac-Semax · NAS · acetylated Semax

N-acetylated Semax without the C-terminal amide. Sits between unmodified Semax and NASA (N-acetyl Semax amidate) on vendor menus. Same parent evidence base as Semax; this analog does not have its own clinical trial literature.

Not FDA-approved - research chemical

Quick answer

What it is: N-acetylated Semax without the C-terminal amide.

Typical research dose: 200-600 mcg/day (intranasal)

Reconstitution calculator ↓

Research summary, not medical advice.

Reviewed by Kymata Health Editorial Team
Last updated: August 2026Evidence: Low
Typical research dose
200-600 mcg/day (intranasal)
Frequency
1-3× daily (intranasal)
Half-life
Not published for this analog
Common vials
5 mg / 10 mg
CAS
N/A
Molecular weight
Heptapeptide analog

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Cognition3/10

    Parent Semax only. This acetyl-only analog has no extra trial.

Compound card

Sequence
N-acetyl Semax (no C-amide)
Class
Middle SKU between Semax and NASA
Formula
N-acetyl Semax
Status
Not FDA-approved · research use
Dose it
5 mg + 5 mL BAC water → 1 mg/mL · 200 mcg ≈ 20 units (U-100)
Open in calculator

How it works

N-acetyl Semax is only the N-terminal cap - no C-amide. It is the middle SKU between Semax and NASA. Evidence remains parent Semax; this page exists because vendors list it separately.

Source: Parent compound: Semax

Research Use Cases

  • ✓Cognitive research: Low

Dosing

PhaseDoseFrequencyNotes
Intranasal (vendor range)200–600 mcg/day1–3× dailySame ballpark as unmodified Semax. Not a label.

Administration

Route / form
Intranasal
Timing
As with Semax - often morning.
Empty stomach?
No - Food timing is not critical.

N-Acetyl Semax: Nasal spray / drops vs Research vial SubQ

Nasal spray / drops
Bioavailability
Minutes-class systemic t½ is why the spray exists. Intranasal is a CNS-delivery argument, not a published US F% table for this SKU. Do not print “~100% CNS delivery” as if it were an FDA bioavailability number.
Dose note
Reconstitute the lyophilized cake, then dose the nose. Community ranges sit in the low-hundreds of mcg per day, split 1–3×. That is research-chem / CIS practice, not a US label. Do not run a BPC-style daily SubQ chart on a nasal insert.
Advantages
  • Matches how the Russian product and most US research SKUs are actually used.
  • Short plasma t½ is the reason people do not treat this like a depot GH peptide.
  • Acetyl-only analog. Parent evidence stays on the Semax leaf. Not NASA (acetyl + amide).
Considerations
  • Sold as a nasal research SKU. Not a US NDA. This analog inherits papers from Semax. It does not have its own human PK package.
  • Nasal irritation is the usual complaint. Volume and osmolarity of a reconstituted cake are not a pharmacy spray.
  • Recon math is for making a solution. It is not a BAC SubQ lifestyle protocol.
Research vial SubQ
Bioavailability
Same cake, different hole. SubQ is community use of a nasal peptide. There is no head-to-head human PK that makes the shot “stronger.” Minutes-class parent t½ still applies.
Dose note
If the bottle is lyophilized and you inject it, BAC-reconstitute and do the unit math. Community mcg numbers are borrowed from nasal practice. Food does not change the shot. This is not a second official SKU.
Advantages
  • Vial math is checkable when the COA matches the sequence.
  • Useful only if you knowingly bought a cake and chose SubQ. It does not create a US injectable drug.
Considerations
  • Not the Russian labeled route. Do not invent a clinic IM ampoule because a vendor sold powder.
  • Systemic exposure is not a published reason to skip the nose.
  • Acetyl-only analog. Parent evidence stays on the Semax leaf. Not NASA (acetyl + amide).
Recommendation: N-Acetyl Semax: nasal is the honest default. SubQ is the same research cake used as an injection, not a second approved product. Sold as a nasal research SKU. Not a US NDA. This analog inherits papers from Semax. It does not have its own human PK package. Do not flatten a spray insert into a BPC reconstitution calendar.

Timeline

Acute
Unmeasured vs parent Semax in head-to-head human PK.

Who it is for

Cognitive research

Low

If you want the evidence base, read Semax. This analog is a catalog SKU.

Reconstitution

Vial
5 mg
Diluent
5 mL
Concentration
1 mg/mL
Per Unit (100u syringe)
10 mcg
Dose of 200 mcg = 20 units on a 100-unit insulin syringe

Safety & Considerations

Research analog. Same class caveats as Semax. Thin human safety file for the acetylated form specifically.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change - verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

  • No independent human PK.
  • Do not treat three vendor names as three drugs.

Verdict

N-acetyl Semax is a catalog split, not a third Semax program. Evidence stays on the Semax leaf.

Interactions & Contraindications

Research analog. Same class caveats as Semax. Thin human safety file for the acetylated form specifically.

Frequently Asked Questions

Nasal or injection?▼
This analog is sold as a nasal research SKU. SubQ is the same cake in a different hole, not extra human PK. Read Semax for the papers. NASA (acetyl + amide) is one more catalog split.
NASA vs N-acetyl Semax vs Semax?▼
Semax = parent. N-acetyl Semax = acetyl only. NASA = acetyl + amide. Stability theoretically increases along that list; published human PK does not.

Prescription options: compare licensed telehealth providers

Some peptide therapies are available only by prescription after a consult with a licensed clinician.

Compare telehealth →
← Back to Peptide Library