STUDresearch · Peptide

Semax family variants

Also known as

Semax analogues · Semax analogs · Met-Semax discussion · N-Acetyl Semax family · NA-Semax / NASA family · N-Acetyl Semax Amidate family · ACTH(4-10) Semax-related peptides · MEHFPGP variants · Adamax (Semax-family discussion) · Semax Amidate · Ac-MEHFPGP / Ac-MEHFPGP-NH2

Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.

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Peptide Some talk Systemic Intranasal Cognitive / nootropic peptides

Brain-focused Semax-family discussion, mainly intranasal; minority SubQ reports do not establish selective human tissue delivery.

What people say Semax is the MEHFPGP heptapeptide; N-acetyl, amidated and Adamax-labeled products are distinct variants whose human equivalence and pharmacokinetics are not established. Doses people talk about

Plain Semax discussion~300–600 mcg nasal, 1–3 times daily

A repeated legacy chart, not a validated Western protocol or a value that transfers to capped variants.

N-acetyl Semax amidate first-time accountLabeled 100 mcg nasal spray; first-evening delivered amount uncertain

First-evening subtle focus occurred with prescribed Depakote ER, doxepin and propranolol. The same author's next-day multi-supplement stack was near-null for NASA with lightheadedness; this was not a standalone repeat.

Amidate adverse account285 mcg per nasal spray; two sprays daily for 2 days, then one spray on day 3

The author reported cognitive worsening and disclosed atomoxetine 100 mg; neither causality nor product identity is verified.

These are preserved charts and unverified self-reports, not bioequivalent regimens or medical dosing. Product concentration, atomizer output and co-exposures limit comparison.

Half-life & effect duration

Half-life in the body: Plain Semax · secondary estimateAbout 2–5 minutes
N-acetyl amidate · vendor estimateAbout 20–30 minutes
Felt duration people report: Plain · community effect estimatesAbout 2–4 hours
Capped forms · community effect estimatesAbout 4–8 hours or longer
Other accountsSubtle focus, next-day nonresponse, no effect across 3 days, or brain fog and sleep problems

Timing context & sources

How it may feel Reports conflict: subtle first-evening focus was not repeated in the same author's next-day stack update; another author reported three null days, and an amidate author reported brain fog while taking atomoxetine.

Cycles people discuss Forum and vendor notes describe short work blocks and multi-week courses, but no controlled comparison establishes a preferred cycle for plain versus capped variants. Timing Legacy notes place use in the morning or early afternoon, often ending by 1–3 PM because of sleep complaints; this is reported timing habit, not a validated interval. Stacks Selank is the most repeated companion in the preserved discussion, while caffeine, racetams and prescription stimulants create additional attribution and tolerability confounding. Watch for Source quality: Mislabel, underfill, degradation, bacterial contamination — separate from intrinsic peptide risk.

Tap a line to jump into the full notes. Research only — may be wrong.

Timing context & sources

Half-life in the body

No dependable human parent half-life or intranasal exposure profile was established.

FDA's 2026 review describes rapid hydrolysis in rat blood and brain tissue and rat intranasal distribution, but did not identify a human PK package. Capped variants have still less human PK evidence.

Rat and in-vitro parent evidence cannot supply human or capped-variant half-life, bioavailability, Cmax or AUC.

FDA 2026 briefing document for Semax-related bulk drug substances (opens in a new tab)PDF zero-based pages 33–34, pharmacokinetics/toxicokinetics: rat IV/intranasal distribution and rat blood/brain tissue hydrolysis. Zero-based page 37, clinical PK: no identified human studies for Semax free base/acetate via any route. Ordinary acetate salt is not N-acetyl modification; this review does not measure capped-variant human PK.Regulatory evidence review, not a clinical PK trial; several cited primary studies are old, animal or in-vitro and not all were independently accessible in English.

Felt duration people report

Nasal accounts include subtle focus, same-author next-day near-null response, a separate three-day null course and cognitive worsening.

Sam-Wolf-Medium described a head sensation around five minutes and several hours of subtle focus with prescription co-use, then little or no repeat NASA effect and lightheadedness in a next-day supplement stack. Tek-War's distinct 100 mcg spray course was null over three days. A 2026 amidate author reported brain fog by day 3 with atomoxetine 100 mg during burnout recovery.

Unverified variant labels and spray output, uncertain delivered amount, expectation effects and different prescription/supplement co-exposures; head-sensation onset is not established focus onset, and no typical duration or prevalence follows.

Documenting my first time experience with Semax (opens in a new tab)Sam-Wolf-Medium opening and same-author Update 1/29/2021 plus day-2-nearly-nothing reply: labeled 100 mcg NASA, uncertain delivered amount, five-minute head sensation and several-hour subtle focus with prescribed Depakote ER 500 mg, doxepin 50 mg and propranolol 10 mg. Next-day two sprays per nostril with uridine, CDP choline, KSM-66 and Longvida (300 mg each) gave calm, later lightheadedness and little/no repeat NASA effect. The 1–2-hour redose is not this author.Single unblinded changing-stack report, uncertain preparation/delivery and product identity, prescribed medication co-exposures and next-day supplement additions; no controlled washout or stable repeat effect.
N-Acetyl-Semax-Amidate Acetate, a bit of a let down (opens in a new tab)Tek-War opening Day 1/2/3 paragraphs: two total 100 mcg sprays on day 1 separated by 1–2 hours, two on day 2, four on day 3; no noticeable effect. Coffee avoided except one cup on day 2, with a brief headache. Other authors' experiences are separate.Single unblinded report, short duration, unverified product and spray output; other commenters are separate authors and were not merged into the OP course.
Brain fog from NA Semax Amidate (opens in a new tab)OP and same-author clarification reviewed: labeled 285 mcg per spray; two sprays on each of the first two days, one on day 3; word confusion, losing reading place, forgetfulness and time blindness; atomoxetine 100 mg disclosed.Single short self-report, unverified product and causality, burnout and atomoxetine co-exposure; later agreement by another user is a distinct author.

What people say 14

Focus (family-wide): Cleaner task focus and less mental drift; often framed less jittery than caffeine megadoses or amphetamine-class stacks. forum
Plain Semax “pulse”: Many describe a sharper, shorter cognitive window (often ~2–4 h subjective) — good for timed work blocks; densest “classic nootropic peptide” lore. forum
Longer window (N-Acetyl / NASA): Modified forms frequently credited with multi-hour usable focus (forum/vendor tables often ~4–8 h, sometimes “6–12+ h” via BDNF cascade talk) and fewer redoses than plain. forum
Higher intensity per mcg (NASA): Dual-cap logs often call NASA more stimulating or “hits harder” at equal mass vs plain; some prefer it for deep-work days, others find it too edgy. forum
Lower mcg equivalence talk: Secondary sources and guides often dose N-Acetyl ~30–40% below plain (e.g. ~400 mcg NA ≈ ~600 mcg plain) and put NASA at the low end of Semax mass culture — not formal bioequivalence studies. forum
Mental stamina: Better endurance on dense work, exams, coding, or high-stress cognitive days — framed as reduced afternoon fade rather than a sharp buzz. anecdote
Mood secondary: Mild motivation lift, less mental fatigue, or smoother drive for some; others report pure cognition with neutral mood; a subset finds capped forms more “wired.” forum
Vs stimulants: Often less appetite crash and jitter than Adderall-class for responders; also often less forced drive — non-responders call the whole family subtle-to-nothing. forum
Working memory / task initiation: Easier hold of dense material and lower activation energy in responder reports; healthy-adult controlled data for capped variants are thin. anecdote
Adamax niche talk: Marketed as “stronger/more stable Semax-class” with adamantane lore; community intensity and duration claims sit beside NASA in comparison tables without controlled ranking. forum
Null / non-responders: Recurring minority report no noticeable effect across plain or capped sprays — product quality, nasal technique, sleep, and expectation are the usual debates. forum
Stack confounding: Very often co-logged with Selank-class, caffeine, racetams, Noopept, or prescription stims — single-agent credit is unreliable. forum
BDNF / neurotrophin story: Parent animal and clinical work (hippocampal BDNF/NGF, trkB, plasma BDNF rises in some stroke-rehab series) is the mechanism forums apply to acetylated/amidated analogs by structural analogy. animal
Neuroprotection interest: Forum interest inherits Russian stroke, cerebrovascular, and optic-nerve framing of parent Semax (e.g. multi-mg clinical courses under supervision) — not proof gray-market analogs replicate those outcomes. trial

Doses people talk about 17

Critical rule — don’t cross-label doses: Pharmacy Semax 0.1%/1% ≠ research N-Acetyl ≠ NASA ≠ Adamax mg-for-mg. Stroke-range multi-mg parent courses are not templates for dual-capped research sprays. forum
Plain Semax — beginner / light nasal: ~100–300 mcg per administration, 1–2× daily — common first band in guides and forums. forum
Plain Semax — modal community cognitive: ~250–600 mcg per dose, 1–2× (often 1–3×) daily; many charts call ~300–600 mcg 1–3× daily the standard nootropic schedule. forum
Plain Semax — broader per-dose / daily talk: ~250–1000 mcg nasal per administration and roughly ~300–1500+ mcg/day split appear across Russian-style summaries and research-chem charts. forum
N-Acetyl Semax (single cap): Similar mcg bands to plain but often fewer daily doses for claimed longer duration; some secondary sources dose ~30–40% lower than plain (e.g. ~400 mcg NA vs ~600 mcg plain as rough equivalence talk). Community nasal logs often ~100–300 mcg class per dose for “potent analog” charts. forum
NASA (N-Acetyl Amidate) — modal Western nasal: ~200–400 mcg once or twice daily is the most repeated research-chem default band. forum
NASA — broader community band: ~100–600 mcg per administration; Reddit-era logs also cite ~150–200 mcg Amidate as “effective” when plain was ~600 mcg, and total daily ~0.2–1.2 mg depending on product and response. forum
NASA — lower “potent analog” charts: ~100–300 mcg per administration 1–2× daily, arguing dual caps justify lower mass than plain’s ~200–600+ mcg/day class; some user guides say NASA needs ~60–70% of standard Semax dose. forum
NASA injectable minority: Charts sometimes start ~500 mcg subQ once daily, escalate toward ~1,000 mcg once or twice daily — minority vs nasal. forum
Adamax (family comparison talk): Vendor/community charts commonly ~100–300 mcg per admin (sometimes up to ~500–1000 mcg/day SC titration tables); once daily often justified by “longer-acting” marketing — no validated human dose-ranging. forum
Comparison heuristic (not a study): Community tables often list plain Semax ~300–600 µg 2–3×/day, N-Acetyl somewhat lower mass or fewer doses, NASA ~200–400 µg 1–2×/day, Adamax ~200–400 µg often 1×/day with stronger/stim lore. forum
Timing: Morning and optional early-afternoon second dose preferred; last dose often capped by ~1–3 PM to protect sleep across the family. forum
Titration habit: Start low end of the relevant variant’s band for a few days (nasal tolerability + stim sensitivity), then nudge by real-task focus and sides — do not max pumps day one, especially on NASA/Adamax. forum
NASA — higher vendor/calculator charts: Start ~600–900 mcg/day as 2–3 pumps when pumps are labeled ~300 mcg each; some charts allow up to ~900 mcg/day for ≤30 days or ~600 mcg/day up to ~60 days with washout ≈ on-time. forum
Common pre-made spray math: Research sprays discussed as 0.1% / 0.3% class with ~300 mcg per labeled pump for some NASA products; other commercial labels cite ~240 mcg/spray at 0.20%; plain 0.1% sprays often ~100–300 mcg/pump product-dependent — always verify label + pump volume. forum
Plain Semax — Russian 1% / acute neuro (context only): ~500 mcg/drop class; multi-mg daily totals (e.g. ~3–9 mg/day class or published rehab ~6000 mcg/day × 10 days × 2 courses with ~20-day gaps) under clinical supervision — not healthy nootropic dosing. trial
Framing: Discussed community, vendor, and secondary product ranges for research education only — not medical advice, not prescriptions, not validated Western protocols. mcg/spray and concentration are product-specific and often unverified. forum

How it may feel 8

Nasal onset discussion and two distinct 2021 accounts: Inherited notes describe 15–60-minute nasal alertness, a clearer head, sensory changes or no effect; this is unverified community timing, not an established typical onset. Sam-Wolf-Medium described a labeled 100 mcg NASA spray with uncertain delivered amount, a head sensation around five minutes and several hours of subtle focus while continuing prescribed Depakote ER 500 mg, doxepin 50 mg and propranolol 10 mg. In the same author's January 29 update, two sprays per nostril alongside uridine, CDP choline, KSM-66 and Longvida curcumin (300 mg each) were followed by calm, lightheadedness about an hour later and little or no repeat NASA effect. A separate author, Tek-War, reported no noticeable effect over three days: two total 100 mcg sprays on day 1 separated by 1–2 hours, two on day 2 and four on day 3; one cup of coffee on day 2 coincided with a brief headache. Product identity, delivery, expectations and co-exposures limit attribution. forum
Hours 1–4 (plain bias): Focus window for a work block; plain Semax often described as a cleaner short pulse. forum
Capped-variant coverage lore and a separate adverse course: Inherited N-acetyl / NASA discussion describes 1–6+ hours of coverage from a morning dose; it remains unverified functional-duration lore, not evidence of a depot peptide. Separately, a 2026 NA-Semax-Amidate spray author reported word confusion, losing their reading place, forgetfulness and time blindness after two days at two labeled 285 mcg sprays, then one spray on day 3 during burnout recovery; atomoxetine 100 mg was a co-exposure. The account does not validate the inherited coverage estimate or establish causality. forumanecdote
Day 1: Subtle edge, nasal sting, mild wired feel, or flat response; late dosing may show sleep cost that night even after stim-feel fades. forum
Days 1–3: Check nasal irritation, overstimulation, headache, anxiety flip, and sleep; modified forms sometimes “hit harder” at the same mcg. forum
Days 3–5 / 5–14: Typical short exam or deep-work checkpoint for real-task attention and productivity 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 for some; others plateau, blunt, get irritable, or stop when demand ends. forum

Cycles people discuss 12

Short work blocks: 5–14 day runs around exams, launches, or deep-work sprints — most common Western pattern for plain and capped forms. forum
Standard multi-week courses: ~10–30 day nasal courses common in vendor and community charts for the family. forum
NASA calculator-style longer runs: Some charts allow up to ~30 days at higher daily totals or ~60 days at moderate ~600 mcg/day-class with washout ≈ time on. forum
Adamax cycle talk: Often ~2–4 or ~4–8 week vendor SC/nasal tables — longer continuous blocks than classic plain Semax nasal pulses in some protocols; evidence thin. forum
Pulsed vs continuous: Pulse high-load weeks more than indefinite daily multi-month use across variants. forum
Time off / washout: Several days to several weeks (sometimes “equal to time on”) between blocks to reassess tolerance, sleep, nasal mucosa, and real benefit. forum
Form-switching: Restart or switch plain ↔ N-Acetyl ↔ NASA ↔ Adamax between cycles is common; no controlled head-to-head comparisons exist. forum
With Selank-class: 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 Western users. forum
Signs people take a break: Diminishing focus edge, rising irritability/headache, sleep hit, or feeling dependent on the spray for normal function. forum
Russian parent clinical-style courses: ~7–14 or ~10–30 day 0.1% cognitive/asthenia-style courses; acute neuro courses shorter/higher strength under supervision. trial
Parent pulse examples (context): Published rehab-style 10 days on / ~20-day gap / 10 days on; product talk sometimes 10 days on / ~14 days off / 10 days on — parent history, not NASA-validated protocols. trial

Timing 13

Human parent pharmacokinetics: Inherited secondary sources quote ~2–5 minutes for intact Semax, but the FDA’s 2026 review did not establish a dependable human plasma half-life, intranasal bioavailability, Cmax or AUC. The rapid hydrolysis and brain/blood distribution data cited there are rat or in-vitro findings, not a human 2–5-minute estimate. trialforum
N-acetyl stability lore: Inherited secondary language claims resistance to leucine aminopeptidase and about 30 minutes longer proteolysis resistance than unmodified Semax in plasma/media experiments. This specific comparison was not independently verified here; it is not a measured human half-life, bioavailability or clinical duration. N-terminal end-capping marketing cannot substitute for a variant-specific human PK study. forum
NASA pharmacokinetics: Inherited research-chem/vendor lore quotes a dual-capped N-acetyl + C-amide plasma half-life of ~20–30 minutes versus single-digit minutes for plain Semax. No measured human parent half-life was established for N-acetyl Semax amidate in the inspected material; multi-hour positive, null and adverse reports do not validate that plasma claim. forum
Onset: Minutes to under an hour intranasal for many (~15–30 min commonly claimed) across variants. forum
Dose frequency heuristics: Plain often 2–3× daily nasal; N-Acetyl 1–2×; NASA often once-morning ± optional early-afternoon; Adamax often once-daily in vendor charts — heuristics, not head-to-head PK. forum
Why fewer doses on capped forms: Longer functional-duration lore is the main reason people drop from multi-dose plain Semax to 1–2× NASA. forum
Sleep timing habit: Inherited reports link late dosing with delayed or lighter sleep even after the alerting sensation fades; morning/early-day use is the family-wide discussion bias. The reports do not establish when parent or capped peptide has left human plasma. forum
Oral: Negligible oral bioavailability assumed (GI peptidases) — oral Semax-family is not a serious community route. forum
Route hierarchy: Nasal preferred for nootropic/CNS goals; subQ is minority Western research-chem practice for lyo vials; IP is animal-only. forum
Why PGP tail exists: Pro-Gly-Pro extension framed as enkephalinase resistance vs shorter ACTH fragments; still short serum life for plain MEHFPGP. animal
Feel window ≠ plasma half-life: Multi-hour focus claims (plain often ~2–4 h; capped often ~4–8 h or longer in tables) are tied to BDNF/NGF cascade and monoamine modulation talk, not blood levels alone. animal
BDNF gene timing (preclinical parent): Bdnf/Ngf transcription changes reported within ~30–90 min after exposure in cell/rodent work; expression can return toward baseline over hours. animal
Nasal nose-to-brain framing: Small heptapeptide + intranasal route discussed for olfactory/trigeminal CNS access; dual caps framed as helping mucosal residence — NASA-specific superior brain AUC in humans is not proven. forum

Stacks 14

+ Selank family (classic dual): Top stack — plain or N-Acetyl/amidate of each for “focus + calm”; Semax-class for drive/BDNF story, Selank-class for anxiolysis/GABA-adjacent calm. forum
Rough mass pairing talk: Community examples often ~300–600 mcg Semax-class AM with ~250–600 mcg Selank-class same day; some clinic/vendor combos market ~50:50 blends; DIY usually keeps separate bottles for flexible ratios. forum
Split timing: Semax/NASA morning for focus; Selank-class midday or later for calm — keeps activation earlier. forum
Stabilized pair: N-Acetyl Semax Amidate + N-Acetyl Selank Amidate is the modern research-chem default dual. forum
+ Racetams / phenylpiracetam / Noopept: Common Western nootropic stack — multi-agent confounds single-agent credit; theoretical “too much neurotrophin” talk is mostly armchair. forum
+ Caffeine / L-theanine: Very common layer; strong coffee + high NASA is a frequent overstimulation path. forum
+ Prescription stimulants (ADHD meds): Discussed for potentiation of psychomotor edge — also higher anxiety, insomnia, and attribution mess; medical-supervision territory. anecdote
+ BPC-157 / recovery peptides: Occasional biohacker co-logs for systemic recovery + CNS focus narratives — attribution messy. anecdote
+ DSIP / sleep tools: Used when Semax-class sleep cost is a problem — Semax morning-only, sleep support at night. forum
+ Lion’s Mane / lifestyle neurotrophins: Community “BDNF stack” talk; confounded by sleep, training, and study structure. forum
+ Pinealon / P21 / Dihexa / Cerebrolysin: Occasional “neuro stack” co-mentions for structural or multi-pathway lore — sparse controlled data. forum
Switch forms vs stack same backbone: Many cycle plain vs NASA or NASA vs Adamax instead of combining two Semax backbones (overlapping pathways, confounded dose–response). forum
Solo-first habit: Introduce one variant alone for several days before Selank-class or stims so nasal sides, sleep, and anxiety can be attributed. forum
Basics as “stack”: Sleep, training, and study structure often co-credited when outcomes look good. forum

Storage notes 2

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

Related 8

Watch for 22

Nasal irritation: Burning, stinging, dryness, congestion, sneezing, or runny nose — the most common local downside across plain and research sprays; carrier harshness and frequency matter. forum
Overstimulation / edginess: Higher mcg or dual-modified forms (NASA, Adamax lore) → restlessness, tension headache, irritability, or “too wired without productive focus.” forum
Sleep hit: Alerting family; late doses can wreck sleep — morning-only or last dose before early afternoon is the usual workaround. forum
Headache / head pressure: Mild headache or brief dizziness in a minority; more discussed above higher daily totals, with stacks/dehydration as confounders. forum
Anxiety / racing thoughts: Subset reports more anxiety or rumination, especially on stim stacks or NASA-style intensity — opposite of “clean calm focus” marketing. anecdote
Irritability / comedown edge: Irritability at higher doses or as effects fade; often cited as a reason to pair Selank-class. forum
Nausea / nonspecifics: Mild nausea or brief dizziness in a minority; stacks confound. forum
Taste / sensory: Metallic or bitter post-nasal drip, brief nasal pressure, short sensory brightening then flat. forum
Fatigue or emotional flatness: Occasional multi-week daily-use reports. anecdote
Hair-loss claim: Circulates as Semax-class anecdote; clinically unconfirmed. anecdote
Vision anecdotes: Rare long-term nasal-user stories of visual change appear on forums — causal link unproven; still a caution flag people mention. anecdote
Injectable local sides: Redness, swelling, or injection-site irritation if using subQ research protocols. forum
Identity / label risk: Gray-market mix-ups among Semax / N-Acetyl / NASA / Adamax labels independent of parent literature; concentration and fill volume are trust-the-label problems. forum
0.1% vs 1% mix-up: Confusing cognitive-strength parent drops with stroke-strength 1% product is a serious dosing error risk. forum
Unit errors: Writing mg when meaning mcg (or reverse) is a recurring forum failure mode. forum
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 interaction matrix for NASA/Adamax. forum
Source quality: Mislabel, underfill, degradation, bacterial contamination — separate from intrinsic peptide risk. forum
Special populations: Pregnancy, lactation, uncontrolled hypertension, active psychiatric disease, seizure history, polypharmacy — generally listed as avoid/caution in clinic-style Semax write-ups; capped analogs are less studied still. forum
Sports / WADA context: Parent Semax often discussed under non-approved substance risk for tested athletes; research analogs are not approved Western therapeutics. forum
Parent trial notes (context): Russian clinical literature generally reports a benign profile; secondary summaries mention nasal-cavity discoloration in a minority class in some write-ups, rare dysgeusia, and blood-glucose discussion in people with diabetes — apply to capped analogs only by analogy. trial
Not risk-free: Short plasma half-life and “research only” labels do not mean zero CNS, mucosal, or unknown long-term risk. forum
Analog evidence gap: Parent has more clinical framing; pharmacy safety history ≠ every Western research spray or dual-capped SKU. trial

Updated: 2026-08-12

Evidence mix Mostly community / anecdote tags Full: every bullet (trial + community). Use Scan for a faster bro-science read.

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Half-life & effect duration

Timing context & sources⌄

Half-life in the body

Felt duration people report

What people say 14

Doses people talk about 17

How it may feel 8

Cycles people discuss 12

Timing 13

More on what it is 11

Stacks 14

Storage notes 2

Related 8

Watch for 22

Timing context & sources