STUDresearch · Peptide
N-Acetyl Semax Amidate
Also known as
NASA · NA-Semax Amidate · NA Semax Amidate · NA-Semax-Amidate · Acetyl Semax Amidate · N-Acetyl-Semax-Amidate · N-Ac-Semax-NH2 · Ac-MEHFPGP-NH2 (sequence shorthand) · Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2 · N-Acetyl Semax (related single-cap analog — not identical) · Semax Amidate (informal; incomplete name)
Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.
Peptide
Some talk
Systemic
Nasal
Cognitive / nootropic peptides
Brain-first research analog — intranasal discussion dominates; SubQ is a minority systemic route, and oral use is not established.
What people say
N-Acetyl Semax Amidate is the dual-capped Ac-MEHFPGP-NH2 Semax analog. Its separate identity is catalogued, but human efficacy, safety and pharmacokinetic evidence is largely parent-Semax analogy rather than NASA-specific trials.
Doses people talk about
Metered-spray delivery and labeled concentration vary, and parent Semax pharmacy drops are a different molecule and product. These reports do not establish NASA bioequivalence or a recommended amount.
How it may feel
Reports conflict: some describe awake, calm focus or sustained attention, while others report no response, brain fog, anxiety, a crash, headache or poorer sleep. Claimed onset runs from minutes to no discernible effect, and product and stacks are major confounders.
Inspected nasal comparison400 mcg nasal
One user reported less response than with 800 mcg regular Semax; another participant at the same product reported immediate mood and motivation plus brain fog and anxiety. Product identity was not independently verified.
Modal nasal discussion~200–400 mcg once or twice daily
The most repeated Western research-chemical chart band; not a tested human standard.
Broader nasal discussion~100–600 mcg per intranasal administration
Some logs also describe roughly 0.2–1.2 mg/day totals; response, product and delivery are uncertain.
Higher nasal chart~600–900 mcg/day
Vendor-calculator territory tied to labeled pump assumptions and course limits, not independent PK evidence.
Minority SubQ chart~500 mcg once daily; some charts reach ~1,000 mcg once or twice daily
Minority research-chemical discussion, distinct from Russian intranasal parent-Semax practice and unsupported as a NASA human standard.
Half-life & effect duration
- Half-life in the body
- Amidate · community estimateAbout 30 minutes
- Felt duration people report
- Community focus-duration estimatesAbout 4–8 hours; other reports say 6–12+ hours
- Other experiencesNo response, crash, anxiety, brain fog or sleep disruption
Cycles people discuss
Forum and vendor calendars describe 5–14-day work blocks, 10–30-day courses and breaks from days to weeks. These are use patterns, not evidence of a necessary biological cycle or a validated washout.
Timing
Morning use, sometimes with an early-afternoon repeat, dominates the notes; last-use cutoffs around 1–3 p.m. are discussed because of sleep disruption. These are reported habits, not a proven sleep-safe cutoff.
Stacks
Selank-class products, caffeine or L-theanine, and Noopept are common co-reports. Those combinations make mood, focus, anxiety and sleep changes harder to attribute to NASA itself.
Watch for
Overstimulation / edginess: “Too wired,” restlessness, or intense motivation without productive calm — more reported with NASA than with plain Semax in some older forum comparisons, and worse with caffeine/stims.
Tap a line to jump into the full notes. Research only — may be wrong.
Timing context & sources
Half-life in the body
A NASA-specific human parent half-life is not established by the reviewed evidence.
PubChem establishes the distinct Ac-MEHFPGP-NH2 identity. FDA's 2026 review found no published human PK for even the different parent Semax free-base or acetate substances; it does not validate NASA kinetics.
The formal sources establish identity and a parent-Semax evidence gap, not a universal literature census for NASA. Vendor claims such as ~30 minutes were not promoted to measured PK.
- PubChem Compound Summary CID 172638603 — N-acetyl semax amidate (opens in a new tab)Identity record lists N-acetyl semax amidate, sequence MEHFPGP, condensed structure Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2 and molecular formula C39H54N10O10S.Chemical identity database entry; it does not provide human route, bioavailability, efficacy, safety or pharmacokinetic measurements.
- FDA 2026 PCAC presentation — Semax-related bulk drug substances (opens in a new tab)Semax deck slide 33 (combined PDF page 135) states that FDA found no published human pharmacokinetic studies for Semax free base or Semax acetate by any route.The review covers parent Semax free base and acetate, not the separately capped NASA analog; it is useful only as negative parent context and cannot establish NASA PK.
Felt duration people report
Reports range from immediate awake or focused effects to no response, crash, anxiety, brain fog and sleep disruption; a stable felt-duration range is not established.
One multi-month nasal user described alert, calm attention while also using P21; another thread contained 400 mcg nonresponse, immediate benefit with brain fog/anxiety, and a separate crash/insomnia report. Another user said the amidate lasted too long and disturbed sleep.
Anonymous uncontrolled reports with uncertain product identity, inconsistent routes and amounts, stacks, underlying conditions and no blinded timing measurements.
- Few questions about semax — multi-month N-Acetyl Semax Amidate account (opens in a new tab)Complete visible thread and same-author replies: a multi-month intranasal user described awake, alert, happy and sustained attention after switching from Semax, with P21 later added; no numeric NASA amount was supplied.Single uncontrolled self-report from a self-described 53-year-old with severe post-COVID symptoms, concurrent clinic treatment and later P21 use; product identity, EEG interpretation and causality were not independently verified.
- N-Acetyl-Semax-Amidate Acetate, a bit of a let down — conflicting experience thread (opens in a new tab)Visible thread: the author compared 400 mcg amidate with 800 mcg regular Semax and reported less response; replies included immediate mood/motivation with brain fog and anxiety, and a separate euphoria-to-crash, headache, depression and poor-sleep account.Anonymous reports with different users, products, routes, amounts and co-exposures; same-author follow-up did not establish a durable effect window or product assay.
- Game changer — Semax experience and amidate duration reply (opens in a new tab)Visible post and replies: a participant using two sprays of N-acetyl Semax said the amidate version lasted too long and interfered with sleep; no calibrated NASA mass or duration was provided.Brief anonymous comparison without product assay, exact timing, dose mass or controlled rechallenge; the main post discussed Semax generally, not necessarily NASA.
What people say
- Focus / sustained attention: Cleaner multi-hour focus with less mental drift; frequently preferred over plain Semax when people want a longer usable cognitive stretch rather than a short pulse. forum
- Longer functional window: Vendor and forum tables often put NASA feel/duration ~4–8 h (sometimes “6–12+ h” for downstream neurotrophin talk) vs ~2–4 h for plain Semax — functional duration, not plasma half-life. forum
- Lower mcg vs plain: Many guides dose NASA ~30–40% lower than plain Semax mass for a similar feel (e.g. ~200–400 mcg NASA vs ~300–600 mcg plain as modal bands); not formal head-to-head PK proof. forum
- Mental stamina: Better endurance on deep-work, exam, coding, or long-meeting days — described as reduced afternoon fade rather than a sharp buzz. anecdote
- Mood / drive: Mild motivation lift or less mental fatigue in some; neutral mood in others; a subset finds it more stimulating/intense than plain Semax. forum
- Vs stimulants: Less jitter, crash, and appetite smash than caffeine megadoses or amphetamine-class for many; also often less forced drive — some non-responders call it “subtle to nothing.” forum
- Working memory / task initiation: Easier hold of dense material and lower “activation energy” to start tasks in responder reports; healthy-adult controlled data for NASA specifically are thin. anecdote
- Amphetamine / stim potentiation talk: Older nootropic-forum logs sometimes describe NASA co-dosed with low-dose ADHD stims as amplifying psychomotor edge — also higher wired/insomnia risk; confounded multi-agent logs. anecdote
- Null / non-responders: A recurring minority report unnoticeable effects even from ~300 mcg to multi-mg nasal; product quality, technique, and expectation are the usual debate. forum
- Stack confounding: Very often co-logged with NA-Selank Amidate, caffeine, racetams, Noopept, or stimulants — single-agent credit is unreliable. forum
- BDNF / neurotrophin story (mostly parent): Parent Semax animal work shows hippocampal/cortical BDNF/NGF and trkB changes; human stroke-rehab series report plasma BDNF rises with functional scores — NASA inherits this narrative by structural analogy. animal
- Neuroprotection interest: Inherited from Russian Semax stroke, cerebrovascular, and optic-nerve framing (e.g. multi-mg clinical courses under supervision) — not proof that gray-market NASA replicates those outcomes. trial
Doses people talk about
- Modal Western NASA nasal band: ~200–400 mcg once or twice daily is the most repeated “default research-chem” band across peptide guides and cycle tables. forum
- Broader community nasal band: ~100–600 mcg per administration appears widely; Reddit-era logs also cite ~200–600 µg insufflated and total daily bands roughly ~0.2–1.2 mg depending on response and product. forum
- Injectable minority charts: Start ~500 mcg subQ once daily, some charts escalate toward ~1,000 mcg once or twice daily — still minority vs nasal; not Russian pharmacy practice for this analog. forum
- Lower “potent analog” charts: Some research blogs put NASA at ~100–300 mcg per administration 1–2× daily, arguing dual caps justify lower mass than plain Semax’s ~200–600 mcg/day class. forum
- Vs plain Semax equivalence talk: Secondary sources sometimes frame ~400 mcg N-Acetyl Semax ≈ ~600 mcg plain (~30–40% lower); NASA is often treated as the strongest of the three on a per-mcg basis and dosed at the low end of Semax culture — not a formal bioequivalence study. forum
- Vs Adamax (related talk): Community tables often list plain Semax ~300–600 µg 2–3×/day, NASA ~200–400 µg 1–2×/day, Adamax ~200–400 µg often 1×/day with “stronger/more stim” lore — same mass band, different duration/intensity stories. forum
- Timing: Morning and optional early-afternoon second dose preferred; last dose often capped by ~1–3 PM to protect sleep. forum
- Titration habit: Start low end of the band for a few days (nasal tolerability + stim sensitivity), then nudge by real-task focus and sides rather than maxing pumps day one. forum
- Higher vendor / calculator charts (e.g. peptides.org-style): Nasal start ~600–900 mcg/day as 2–3 pumps (when pumps are labeled ~300 mcg each), titrating by response; some charts allow up to ~900 mcg/day for ≤30 days or ~600 mcg/day for up to ~60 days with washout ≈ on-time. forum
- Common pre-made spray math: Vendor sprays discussed as 10 mg/10 mL (0.1%) or 30 mg/10 mL (0.3%) with ~300 mcg per labeled dose/pump in secondary sources — actual pump volume must match the label assumption. forum
- Parent Semax pharmacy context (different product): Russian 0.1% (~50 mcg/drop class) cognitive courses and 1% multi-mg stroke courses are not NASA dosing templates; do not copy stroke-range multi-mg totals onto dual-capped research-chem sprays. trial
- Framing: Community and vendor research ranges only — not medical advice, not prescriptions, not validated Western protocols. mcg/pump and concentration are product-specific and often unverified. forum
How it may feel
- Minutes 15–60: Common subjective nasal onset — mild alertness, sensory “on,” cleaner verbal fluency, or nothing; technique and product vary widely. forum
- Hours 1–6+: Claimed focus window for a work block; dual-cap lore used to justify longer coverage than plain Semax’s shorter pulse. forum
- Day 1: Subtle edge, nasal sting, mild wired feel, or flat response; late dosing may show sleep cost that night even after “stim feel” is gone. forum
- Days 1–3: Check nasal irritation, overstimulation, headache, anxiety flip, and sleep; many decide if the edge is real vs placebo. forum
- Days 3–5 / 5–14: Typical short “exam or deep-work block” checkpoint for real-task focus and mental stamina claims. forum
- Days 7–14: Some guides frame cumulative BDNF/gene-expression style build (borrowed from parent Semax talk) peaking mid-course rather than caffeine-like day-1 fireworks. forum
- Weeks 2–4: Steadier stamina across a course for some; others plateau, blunt, get irritable, or stop when demand ends. forum
- After stopping: Residual clarity for a day or two in some logs; fade within 1–2 days for others — permanent cognitive gains are not established. anecdote
Cycles people discuss
- Short work blocks: 5–14 days around exams, launches, or deep-work sprints — the most common Western pattern. forum
- Standard multi-week courses: ~10–30 day nasal courses common in vendor charts; some allow longer (~up to 60 days) only at moderate ~600 mcg/day-class totals with equal-length washout in calculator-style guides. forum
- Pulse pattern: 10–14 days on, 2–3 days off repeated for a few cycles, then a longer 1–2 week break — borrowed from parent Semax “receptor/desensitization” talk. forum
- Washout talk: Several days to several weeks off (sometimes “equal to time on”) to reassess sleep, nasal mucosa, real benefit, and whether effect returns on re-start. forum
- Pulsed vs continuous: High-load weeks more than indefinite daily multi-month use; continuous open-ended NASA logs are less common than pulsed courses. forum
- With Selank / NA-Selank Amidate: Usually same calendar (both on for the course) rather than staggered multi-week offsets; some dose Semax-class AM and Selank-class later. forum
- Re-runs: Before next high-demand window rather than perpetual daily maintenance for most. forum
- Russian parent cycling (context only): Parent Semax clinical examples include 10 days on / ~14 days off / 10 days on and stroke rehab double 10-day courses with ~20-day gaps — historical parent context, not NASA-validated protocols. trial
Timing
- NASA plasma claim: Dual capping said to extend plasma persistence; secondary research-chem sources commonly quote ~30 minutes plasma half-life for NASA vs single-digit minutes for plain Semax, and “~30 min longer” resistance language from N-acetylation stability papers applied to the class. forum
- Onset: Minutes to under an hour nasal for many (~15–30 min commonly claimed). forum
- Dosing cadence: Still 1–2× daily (occasionally 2–3× on higher charts) — not weekly depot-style peptides. forum
- Why fewer doses than plain: Longer functional duration lore is the main reason people drop from 2–3× plain Semax to 1–2× NASA. forum
- Sleep timing reports: Late dosing is linked in community reports to delayed or lighter sleep, with a strong morning/early-day preference. Explanations that the peptide is already “long gone from plasma” are assumptions, not a measured NASA-specific human clearance result. forum
- Oral: Negligible oral bioavailability assumed (GI peptidases) — oral NASA is not a serious community route. forum
- Parent Semax plasma PK: Intact plain Semax often cited ~2–5 minutes (secondary sources; rapid peptidase attack) — short circulating life. trial
- Downstream / feel window: Multi-hour (often ~4–8 h, sometimes “6–12+ h”) focus attributed to BDNF/NGF cascade and monoamine modulation, not blood levels alone — same logic as plain Semax’s “2–4 h feel despite minute-scale plasma.” animal
- Nasal nose-to-brain framing: Small heptapeptide + intranasal route discussed for olfactory/trigeminal CNS access and mucosal peptidase risk — dual caps framed as helping mucosal residence, not proven superior brain AUC in NASA-specific human PK. forum
More on what it is
- What it is: Dual-capped Semax analog — same heptapeptide backbone Met-Glu-His-Phe-Pro-Gly-Pro with N-terminal acetylation (Ac–) and C-terminal amidation (–NH2), often written Ac-MEHFPGP-NH2 or Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2. Approximate MW ~854 Da vs ~813 Da for plain Semax. forum
- Why people use it: Default “enhanced Semax” sold by Western research-chem vendors (NASA / NA-Semax-Amidate labels); claimed longer usable focus window and higher potency per mcg than plain Semax, so lower total mcg and fewer daily doses in many charts. forum
- Why dual caps: N-acetyl blocks aminopeptidases at the free Met amine; C-amide blocks many carboxypeptidases at the free carboxyl — both ends protected vs plain MEHFPGP. forum
- Not the same as: FDA-approved drug; Russian pharmacy Semax 0.1% or 1% drops; plain Semax; N-Acetyl Semax only (single N-cap, no amidate); Adamax (adamantyl/related “stronger Semax” variant); Selank or NA-Selank Amidate. forum
- Mechanism talk: Borrows parent Semax stories — BDNF/NGF upregulation and trkB signaling, monoamine (DA/5-HT) turnover modulation, enkephalinase interaction, anti-inflammatory/ischemia gene programs — with capping framed as stability/PK, not a new receptor target. animal
- Evidence honesty: Human clinical density is almost entirely parent Semax (Russian 0.1%/1% nasal products, stroke/rehab, optic-nerve product history). NASA-specific RCTs in healthy adults are sparse to absent; most NASA claims are analogy + forum + vendor PK lore. trial
- Regulatory: Research-chem / not for human consumption framing in most Western markets; parent Semax is a registered Russian Rx — NASA is not that product. forum
Stacks
- + Selank or N-Acetyl Selank Amidate (classic pair): “Focus + calm” — NASA/Semax-class for drive and BDNF story, Selank-class for anxiolysis/GABA-adjacent calm; most common dual stack. forum
- Same-time AM stack: Both nasal in the morning before work (e.g. community examples in the ~100–300 mcg Semax-class + ~250 mcg Selank-class ballpark, product-dependent). forum
- Split timing: Semax/NASA morning for focus; Selank-class midday or later for calm — keeps activation earlier in the day. forum
- Rough 1:1 mass talk: Some clinic/vendor combos market ~50:50 Semax:Selank blends; DIY users often run separate bottles at similar mcg order rather than a fixed universal ratio. forum
- + Caffeine / L-theanine: Very common layer; strong coffee + high NASA is a frequent overstimulation path. forum
- + Racetams / phenylpiracetam: Older nootropic-forum combos (AMPA/ACh stories + neurotrophin stories); multi-agent logs confounded. forum
- + Noopept: Frequent co-mention for overlapping BDNF/NGF interest; theoretical “too much neurotrophin signaling” debate is mostly armchair. forum
- + Prescription stimulants (ADHD meds): Discussed for potentiation of psychomotor edge — also higher anxiety, insomnia, and attribution mess; medical-supervision territory, not a validated protocol. anecdote
- + Pinealon / P21 / other neuro peptides: Occasional biohacker co-logs for “foundational neuroprotection + structural” narratives — sparse controlled data. forum
- Not usually stacked with plain Semax: Head-to-head comparison or swap is more common than combining plain + NASA (overlapping pathways, confounded dose–response). forum
- Solo-first habit: Introduce NASA alone for several days before adding Selank-class or stims so nasal sides, sleep, and anxiety can be attributed. forum
- Sleep hygiene as “stack”: Earlier last dose often credited as much as the second peptide for good outcomes. forum
Storage notes
- No mix instructions here: STUDresearch does not list reconstitution, diluent volumes, or syringe unit charts. People reconstitute many different ways and vial labels differ — that content creates more confusion than clarity. forum
- Storage (general talk only): Unopened research products are usually kept cool, dry, and away from light per the seller label. Anything after first use is product-specific — follow the label, not a universal forum SOP. forum
Watch for
- Nasal irritation: Burning, stinging, dryness, sneezing, mild rhinitis, or congestion — the most common complaint; frequency and harsh carriers matter. forum
- Headache / head pressure: Transient headache in a minority; more often discussed above ~600 mcg/day-class totals, with stacks/dehydration as confounders. forum
- Overstimulation / edginess: “Too wired,” restlessness, or intense motivation without productive calm — more reported with NASA than with plain Semax in some older forum comparisons, and worse with caffeine/stims. forum
- Sleep disruption: Late dosing linked to delayed or lighter sleep; morning-only or last dose before early afternoon is the common fix. forum
- Anxiety flip / rumination: Minority report more anxiety or racing thoughts despite “clean focus” marketing — response is not uniform. anecdote
- Irritability / comedown edge: Irritability at higher doses or as effects fade; often cited as a reason to pair Selank-class. forum
- Fatigue or emotional flatness: Occasional multi-week daily-use reports (class-level, not NASA-unique RCTs). anecdote
- Taste / sensory: Metallic or bitter post-nasal drip, brief nasal pressure, short sensory brightening then flat. forum
- Injectable local sides: Redness, swelling, or injection-site irritation if using subQ research protocols. forum
- Hair-loss claim: Circulates as anecdote for the Semax class; clinically unconfirmed and not established for NASA. anecdote
- Drug-interaction caution: Parent Semax modulates dopaminergic/serotonergic systems — community and clinic write-ups urge caution with SSRIs/SNRIs/MAOIs, antipsychotics, and stimulants; no formal NASA interaction matrix. forum
- Source quality: Gray-market mislabel, wrong concentration, underfilled bottles, degradation, bacterial contamination — separate from intrinsic peptide risk. forum
- Concentration / unit errors: Confusing plain Semax pharmacy 0.1% vs 1%, or writing mg when meaning mcg, are serious practical risks. forum
- Special populations: Pregnancy, lactation, active cardiovascular disease, seizure history, bipolar disorder, polypharmacy — generally listed as avoid/caution in clinic-style Semax write-ups; NASA is less studied still. forum
- Sports / WADA context: Parent Semax often discussed under S0-style non-approved substance risk for tested athletes; NASA is not an approved therapeutic in major Western agencies. forum
- Parent Semax trial notes (context): Russian clinical literature generally reports a benign profile; secondary summaries mention nasal-cavity discoloration (~10% class in some ADDF/secondary write-ups), rare dysgeusia, and increased blood glucose discussion in people with diabetes — apply to NASA only by analogy. trial
- NASA evidence gap: Most human safety and efficacy language is parent Semax, not dual-capped NASA RCTs; absence of Western healthy-adult trials is not proof of safety for indefinite gray-market use. trial
- Not risk-free: Short plasma half-life and “research only” labels do not mean zero CNS, mucosal, or unknown long-term risk; missing a side effect in one log ≠ safe. forum
Evidence mix
Mostly community / anecdote tags
Full: every bullet (trial + community). Use Scan for a faster bro-science read.