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
Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Low1 peer-reviewed citation
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
Dose it
5 mg + 5 mL BAC water → 1 mg/mL · 200 mcg ≈ 20 units (U-100)
Open in calculator

Mechanism of Action

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 Semax PMID: 17430556

Dosing Protocol

Typical Dose200-600 mcg/day (intranasal)
Frequency1-3× daily (intranasal)
Half-LifeLonger than Semax (estimated; analog PK unpublished)
Common Vial Sizes5 mg, 10 mg

Dosing Protocols

Intranasal (vendor range)

Dose
200–600 mcg/day
Frequency
1–3× daily
Note: Same ballpark as unmodified Semax. Not a label.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 200–600 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)154 mcg309 mcg463 mcg
140 lb(63 kg)180 mcg360 mcg540 mcg
160 lb(73 kg)209 mcg417 mcg626 mcg
180 lb(82 kg)234 mcg469 mcg703 mcg
200 lb(91 kg)260 mcg520 mcg780 mcg
220 lb(100 kg)286 mcg571 mcg857 mcg
250 lb(113 kg)323 mcg646 mcg969 mcg

💉 For exact syringe units based on your vial concentration, use the N-Acetyl Semax Reconstitution Calculator →

Administration

Route
Intranasal
Timing
As with Semax — often morning.
Fasting Required?
No — food timing not critical

Expected Timeline

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

Who Is It For?

Cognitive research

Low

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

Reconstitution Example

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
🧮 Calculate Your Exact N-Acetyl Semax Dose →

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.

Dosing Quick Reference

N-Acetyl Semax— Dosing Guide
Dose Range
200-600 mcg/day (intranasal)
Half-Life
Longer than Semax (estimated; analog PK unpublished)
Frequency
1-3× daily (intranasal)
Route
Subcutaneous
5 mg vial10 mg vial
💧 5 mL BAC water📐 1 mg/mL💉 10 mcg/unit (100u syringe)
Cognitive & Nootropiccalcmypeptide.com

Frequently Asked Questions

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.

References

  1. Ashmarin / Myasoedov lineage “Semax parent literature.” Neuroscience literature (2007). PMID: 17430556

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