# N-Acetyl Semax Amidate

Stabilised, stronger, longer-acting Semax; same use (focus, mental energy).

- Page: https://peprank.xyz/peptides/n-acetyl-semax-amidate
- Category: Focus & memory (Research peptide)
- Also known as: NA-Semax-Amidate; NASA
- Routes: Nasal / Injection
- Sequence: MEHFPGP (N-acetyl, C-amide)
- Safety tier: Strict: Caution · Balanced: Caution · Evidence only: Clean
- Risk axes (0 none to 3 severe): Seen harm 0, Mechanism 1, Data gap 3, Silent harm 1, Product 2
- Positive: 55% of 48 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #6 of 61 research peptides
- Graded reports: 48 (Glowing 3, Positive 24, Mixed 4, Nothing 12, Negative 4, Bad reaction 1)
- Evidence: No studies of its own — For the modified form (parent Semax is approved in Russia)
- Access: Grey market
- Onset: 15-30 minutes after a nasal dose; users describe it as subtle rather than a hit.
- Lasts: Roughly 6-8+ hours per dose by user accounts, against about 4-5 hours for plain Semax.
- Cost per month: ≈ €4.8–14 (at 100–300 mcg/day, Semax Polska at €1.59/mg, a blend, no pure pack listed)
- Dose users report: 300–800 mcg/day (median 450 mcg, n=5), ≈ €14–38 a month at that dose
- Updated: 2026-10-30

## What users report

Users who like Semax often prefer the NA/amidate form (stronger mood lift, longer). But overdosing is easier: lethargy, discomfort above ~300 mcg, and a few reports of a crash into low mood or anhedonia after 2-3 days. Around 30-40% still report nothing.

**Effects:** stronger, longer focus than plain Semax; uplifted mood; mental calm for monotonous work; stimulant potentiation

**Downsides:** lethargy or 'too much espresso' discomfort at higher doses; post-use low mood/anhedonia in a few reports; vivid dreams; headache

**Caveat:** Acetylation/amidation of the same sequence; no specific harm path, but no clinical or tox data on the modified molecule and grey-market only. Rated slightly below Semax for that reason.

**Typical use:** 100-300 mcg/day (lower than plain Semax); short courses.

**Getting it:** Sold only by research-chemical vendors as pre-mixed nasal sprays or vials; no approved or compounded version.

**Stacked with:** NA-Selank-Amidate (The most common pairing, both taken in the morning; Selank is meant to blunt the anxiety and irritability NA-Semax can bring.); Caffeine, modafinil or methylphenidate (Users say it amplifies stimulants noticeably; several end up cutting their caffeine because of it.); Bromantane (Popular on r/NooTopics for drive and motivation; reported as a good pairing, without trial data.)

## Risk profile

- **Seen harm 0/3:** Around fifty first-hand reports include low mood, brain fog and one depressive dip from day three, but nothing reaching emergency care or lasting harm. This zero reflects community use only: no study has looked.
- **Mechanism 1/3:** The same active sequence as Semax with both ends capped to slow breakdown, so it inherits Semax's speculative neurotrophin effect; the only comparison paper found acetylation changes copper binding in vitro, which is not a harm path.
- **Data gap 3/3:** No human, animal toxicology or pharmacokinetic data exist for the modified molecule; Semax's Russian trials bridge only partly, because capping is meant to make it stronger and longer-acting.
- **Silent harm 1/3:** Reported effects (irritability, low mood, fog) are noticed within a day or two and fade on stopping.
- **Product 2/3:** Sold only by research-chemical vendors as premixed nasal sprays or vials; a few inject it.
- **Never if:** Pregnancy or breastfeeding (no human reproductive data)

## Top reports

- Glowing, focus: “N-Acetyl Semax Amidate was by far the best nootropic i've had. Its a shame its so hard to source :(” — [@sahil_harriram on X](https://x.com/sahil_harriram/status/2038138929879327056)
- Glowing, focus, 300 mcg each morning: “i’m only a week on it, but it’s nothing short of incredible for me rn. tldr: - N-Acetyl Semax Amidate is best - intranasal, 300mcg - once every morning, maybe twice ymmv” — [@__tux on X](https://x.com/__tux/status/1574419814034165763)
- Glowing, memory: “Yes I was like Dory it was very scary - now not an issue. Especially Semax Amidate stronger. No need to inject” — [r/TBI](https://www.reddit.com/r/TBI/comments/1t25t3z/semax_nasal_spray_life_changing_have_my_memory/ooog8zc/)
- Positive, focus, 300-600 mcg/day: “For me, Semax produces a very smooth nootropic feel that kicks in within minutes and lasts all day. My mind feels very sharp when I’m on it, and cognitive tasks are less mentally taxing than usual.” — [@BowTiedNeuron on X](https://x.com/BowTiedNeuron/status/1934618729926570048)
- Positive, recovery, ~1 mg: “I've been taking NA-semax on/off for a week now. It's a surprisingly effective painkiller, comparable to aspirin. Taking a high dose (~1mg) definitely makes me feel different (high/elated?); only side effect of note is dry mouth.” — [@jensenjeans on X](https://x.com/jensenjeans/status/2075421472722661526)

## Cheapest in Europe

- [Penchant Bio](https://penchant.bio/products/na-semax-amidate) (GB): NA-Semax Amidate spray 12 mL at 2 mg/mL (200 mcg/press), €25, €1.05/mg
- [Semax Polska](https://semaxpolska.com/en/n-acetyl-semax-amidate-20-mg/) (PL): N-Acetyl Semax Amidate 20 mg, €32, €1.59/mg (also contains 5 mg GHK-Cu arginate, judged as [GHK-Cu (injectable)](https://peprank.xyz/peptides/ghk-cu-injectable) since the nasal route is systemic: Strict Avoid · Balanced Avoid · Evidence only Caution)
- [Baltic Peptides](https://balticpeptides.com/product/n-acetyl-semax-amidate/) (LT): N-Acetyl Semax Amidate 30mg (Vial), €60, €2.00/mg
- [Baltic Peptides](https://balticpeptides.com/product/n-acetyl-semax-amidate/) (LT): N-Acetyl Semax Amidate 30mg (Nasal Spray), €65, €2.17/mg (contents not stated on the page)
- [Modern Peptides EU](https://modernpeptides.eu/product/na-semax/) (DE): NA Semax 30mg, €72, €2.40/mg

## Studies

- [Magrì et al.: N-terminus acetylation of Semax and copper(II)/zinc(II) coordination and biological properties](https://pubmed.ncbi.nlm.nih.gov/27586814/) (in-vitro, 2016): The only published comparison of Ac-Semax with Semax: acetylation changed copper binding and removed Semax's protection of neuroblastoma cells against copper toxicity.
- [Shevchenko et al.: Stability of Semax acetyl to proteolysis in various biological media](https://pubmed.ncbi.nlm.nih.gov/23652441/) (in-vitro, 2013): Measured how acetylated Semax resists enzymatic breakdown; the short communication has no accessible abstract, so how much stability it gains is unreported.
- [Zolotarev et al.: Degradation of Semax by rat basal forebrain cells and plasma membranes (parent Semax)](https://pubmed.ncbi.nlm.nih.gov/16773243/) (in-vitro, 2006): Plain Semax is cut mainly at its two ends, which is the rationale for capping the N-terminus (acetyl) and C-terminus (amide).
- [Dolotov et al.: Semax regulates BDNF and trkB expression in the rat hippocampus (parent Semax)](https://pubmed.ncbi.nlm.nih.gov/16996037/) (animal, 2006): One intranasal dose of plain Semax raised hippocampal BDNF protein about 1.4-fold; never tested for the NA-amidate form.
- [Gusev et al.: Efficacy of Semax at different stages of ischemic stroke (parent Semax)](https://pubmed.ncbi.nlm.nih.gov/29798983/) (controlled, n=110, 2018): Plain Semax (6000 mcg/day courses) raised plasma BDNF and sped functional recovery after stroke; the human evidence the modified form borrows.

## Sources

- [FDA: Bulk drug substances that may present significant safety risks (Category 2 / withdrawn list, Apr 2026)](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)
- [Mendias & Awan 2026 preprint: 6441 grey-market peptide samples, 41.6-71.1% failed quality criteria, 15% endotoxin](https://europepmc.org/article/PPR/PPR1182497)