Reviewed by the PeptideMind Team · Updated August 10, 2026
Semax vs N-Acetyl Semax Amidate:
Key differences comparison
The main difference between Semax and N-Acetyl Semax Amidate is stability. NA Semax Amidate is the same core Semax sequence with two added modifications, an acetyl group on one end and an amide cap on the other, that make it resist breakdown in the body. That's why it's commonly reported to last longer and be more potent per microgram, though a controlled head-to-head study confirming that potency figure hasn't been published. Semax has decades of Russian clinical use behind it; NA Semax Amidate remains a preclinical research compound.
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What Is Semax?
Semax is a lab-made peptide developed in Russia, built from a fragment of ACTH(4-10), a hormone your body naturally produces. It's studied for supporting memory, focus, and brain recovery, and it carries regulatory approval in Russia and Ukraine for conditions like ischemic stroke and reduced blood flow to the brain.
A well-established, ACTH-based design
Semax is built from a small fragment of ACTH and is studied for boosting BDNF and NGF, proteins linked to brain-cell growth, repair, and protection.
What it's best known for
Supporting mental sharpness, memory, and motivation, with decades of Russian clinical research behind it for stroke recovery and general neuroprotection.
Where it stands legally
Semax is an approved prescription medication in Russia and Ukraine. It has no FDA approval in the United States and is sold strictly as a research chemical.
What Is N-Acetyl Semax Amidate?
N-Acetyl Semax Amidate (NA Semax Amidate) is a chemically modified version of Semax, tweaked to stay active in the body longer and work more efficiently. It's studied for the same BDNF and NGF boosting effects as Semax, but it's considered several times more potent by weight, and is used mainly in preclinical research for nootropic and neuroprotective effects.
A stability-focused redesign
Two small chemical additions, an acetyl group on one end and an amide cap on the other, protect NA Semax Amidate from being broken down as quickly as the original Semax.
What it's best known for
A longer reported duration of action and a reported (though not independently confirmed) 3 to 4 times potency advantage over Semax, driving interest in nootropic research circles.
Where it stands legally
NA Semax Amidate has no regulatory approval anywhere and no human trial history. It's sold online as an unregulated research chemical, strictly for research purposes, not for people to use on themselves.
Semax vs N-Acetyl Semax Amidate at a Glance
A side-by-side look at how Semax and N-Acetyl Semax Amidate differ in how they work, how they're dosed, and where each stands legally.
Overview
- Type
- Single peptide
- Primary category
- Cognitive
- Secondary categories
- Longevity
- Research status
- Approved
- FDA approved
- Not FDA approved
- Popularity
- 7/10
- Body targets
- Brain
- Price range
- Human trial status
- Human pilot studies
- Legal status
- Research chemical
- WADA status
- Not banned
Dosing
- Dose
- 300–800 mcg
- Frequency
- Daily
- Cycle
- 2–4 weeks on, 1–2 weeks off
- Route of administration
- Nasal
- Common vial sizes
- 10mg30mg
Research
- Molecular weight
- 813.93 g/mol
- Half-life
- —
- Median onset
- —
- Prescription alternative
- No alternative
- Receptor target
- MC4R
- Receptor action
- Modulator
- Mechanistic pathways
- Neuropeptide CognitiveMelanocortin Receptor
Included in
Overview
- Type
- Single peptide
- Primary category
- Cognitive
- Secondary categories
- Longevity
- Research status
- Preclinical
- FDA approved
- Not FDA approved
- Popularity
- 3/10
- Body targets
- Brain
- Price range
- Human trial status
- Animal studies only
- Legal status
- Research chemical
- WADA status
- Not banned
Dosing
- Dose
- 100–300 mcg
- Frequency
- Daily
- Cycle
- 4–8 weeks
- Route of administration
- Subcutaneous
- Common vial sizes
- 10mg30mg
Research
- Molecular weight
- 854.97 g/mol
- Half-life
- —
- Median onset
- —
- Prescription alternative
- No alternative
- Receptor target
- MC4R
- Receptor action
- Modulator
- Mechanistic pathways
- Neuropeptide CognitiveMelanocortin Receptor
Included in
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Based on current scores, this vendor ranks highest across those criteria.
Comparison at a Glance: Semax vs N-Acetyl Semax Amidate
A quick side-by-side look at how Semax and N-Acetyl Semax Amidate differ in structure, duration, evidence base, and where each stands legally.
Structural difference
NA Semax Amidate is the same core Semax sequence with two added modifications, an acetyl group on one end and an amide cap on the other, that block the enzymes that normally break the peptide down.
Duration and potency
Those two modifications are commonly reported to give NA Semax Amidate a longer duration of action and a stronger effect per microgram, often cited as 3 to 4 times more potent than Semax, though this figure comes from vendor and community sources, not a published head-to-head study.
Evidence base
Semax has decades of documented use and regulatory approval in Russia and Ukraine. NA Semax Amidate's evidence is limited to preclinical and animal research, with no equivalent human trial history.
Legal status
Semax is an approved prescription medication in Russia and Ukraine. NA Semax Amidate has no regulatory approval anywhere and is sold only as a research chemical.
Semax Dosage Guide for Cognitive EnhancementSemax Dosage Calculator
Semax is a well-known Russian peptide that boosts brain chemicals (BDNF and NGF) linked to memory, focus, and brain protection. It's usually taken as a nasal spray, either every day or on a 5-days-on, 2-days-off schedule.
Vial size
10 mg
Bacteriostatic water
2 mL
Dosing
300–800 mcg
Frequency
Daily
Cycle
2–4 weeks on, 1–2 weeks off
Benefit
Cognitive Enhancement
NA Semax Amidate Dosage Guide for Cognitive EnhancementNA Semax Amidate Dosage Calculator
NA Semax Amidate is an improved, longer-lasting version of Semax that the body absorbs and holds onto better. People use it to think more clearly, protect the brain, boost a brain-growth hormone called BDNF, and ease anxiety, usually via injection or nasal spray.
Vial size
5 mg
Bacteriostatic water
2 mL
Dosing
100–300 mcg
Frequency
Daily
Cycle
4–8 weeks
Benefit
Cognitive Enhancement
Semax vs NA Semax Amidate: Which One Should You Research?
Semax and NA Semax Amidate aren't typically combined, since they're the same core compound in two different forms. The choice usually comes down to whether the research calls for the better-documented original or the longer-acting, more potent modified version.
If a deeper evidence base matters most
Semax has decades of Russian clinical use and regulatory approval behind it, giving it the more established research and safety record of the two.
If duration and potency are the priority
NA Semax Amidate is reported to last longer and require a smaller amount per dose, but that comes with a thinner, mostly preclinical evidence base.
Neither is an approved product in the US
Semax is approved in Russia and Ukraine, not the US. NA Semax Amidate has no approval anywhere. Both are sold strictly for research, not for people to use on themselves.
Frequently Asked Questions: Semax vs N-Acetyl Semax Amidate
Straight answers on how Semax and N-Acetyl Semax Amidate compare, and how each is dosed. For research reference only.
Semax vs NA Semax Amidate: Dosing Basics
Both are typically dosed daily, but the amount, frequency, and cycle length differ because of NA Semax Amidate's longer reported duration and higher reported potency.
Semax dosing
Commonly discussed at roughly 300 mcg per administration, given intranasally twice a day, typically run in 2 to 4 week cycles with breaks in between.
NA Semax Amidate dosing
Commonly discussed at roughly 600 mcg per day intranasally, or 500 to 1,000 mcg per day if injected subcutaneously, given once daily for up to 8 weeks followed by an equal washout period.
Use a peptide-specific calculator
Vial concentration and reconstitution volume change the actual draw for both peptides. Use a dosage calculator to get an exact number instead of guessing from a general range.
What to Expect: A Week-by-Week Timeline
Timelines vary by person, dose, and which version is used, but research and user reports describe a similar general pattern for both.
Day 1 to 7
Focus and mental clarity effects are commonly reported within the first few doses for both compounds, with NA Semax Amidate's effects often described as lasting noticeably longer per dose than Semax's.
Weeks 2 to 4
Cumulative effects on memory, motivation, and mental sharpness are commonly described as building over this window, lining up with Semax's typical 2 to 4 week on-cycle and the early portion of NA Semax Amidate's longer run.
After stopping
Effects are generally reported to fade gradually after stopping either compound, without a described withdrawal pattern, based on available research and user reports rather than controlled clinical data.
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