P21

CNTF-derived neurogenic tetrapeptide · mice/rats only · no human trials

P21 (more precisely written P021) is a small, orally-active peptide engineered from a fragment of ciliary neurotrophic factor (CNTF), a natural nerve-supporting protein. It was designed by Khalid Iqbal's laboratory at the New York State Institute for Basic Research to reproduce CNTF's brain-regenerating effects without CNTF's toxicity, and in mice and rats it reliably increases the birth of new neurons, raises BDNF (a key growth factor for brain cells), reduces the tau and amyloid changes seen in Alzheimer's models, and improves memory. The honest framing is the evidence ceiling: every one of those results is from rodents or cell cultures, almost all from a single lab, and there has never been a human clinical trial, observational study, established human dose, or human safety assessment of any kind. Its blood–brain-barrier penetration is inferred from its effects, not directly measured, and the one test in an independent disease genotype (CDKL5-deficient mice) was largely negative. It is not approved anywhere — it is a research chemical. One critical disambiguation: this P021 is NOT the famous 'p21' cell-cycle / tumour-suppressor protein (gene CDKN1A), which is an entirely different and much larger molecule that happens to share the name.

The short version

P021 is a tiny engineered peptide built from the active piece of ciliary neurotrophic factor (CNTF) — a natural protein that helps brain cells survive and grow. The full CNTF protein was tried as a drug years ago but caused serious side effects like appetite loss and muscle wasting. The idea behind P021 was to keep just the helpful fragment, then bolt on a bulky chemical group (an adamantane cage) so the peptide can survive digestion, be taken by mouth, and cross into the brain. It came out of Khalid Iqbal's lab at the New York State Institute for Basic Research.

In rodents, P021 does a lot of impressive-sounding things: it boosts the birth of new neurons in the memory centre, raises BDNF (a growth factor for brain cells), lowers the tau and amyloid abnormalities seen in Alzheimer's models, and improves memory in maze and recognition tests. Those effects are real and have been repeated across many studies.

Here is the essential caveat: all of that is in mice, rats, and cell cultures — and almost all of it comes from one laboratory. There have been no human clinical trials of P021, no observational studies, no established human dose, and no human safety testing at all. Even its ability to cross into the brain is assumed from its effects rather than directly measured. And the one time it was tested in a different disease genotype (a model of CDKL5 deficiency), it mostly did not work. It is not an approved medicine anywhere; it is a research chemical.

One important name clash to clear up: this P021 is NOT the well-known 'p21' protein from cancer biology (the cell-cycle brake encoded by the gene CDKN1A). That p21 is a completely different, much larger molecule that just happens to share the label. If you read something about 'p21' and cell division, tumours, or senescence, that is the other molecule — not this peptide.

Molecular identity

Specs

Molecular formula: C27H42N6O8
Molecular weight: 578.7 g/mol
Monoisotopic mass: 578.3064 Da

Type: CNTF-derived adamantylated tetrapeptide (small modified peptide)Li et al., FEBS Lett 2010 (PMID 20600002)
Sequence: Ac-DGGLAG-NH₂ (acetyl-Asp-Gly-Gly-Leu + C-terminal adamantyl-glycine, amidated)Li et al. 2010 (PMID 20600002); ADDF Cognitive Vitality report
Derived from: Active region of human ciliary neurotrophic factor (CNTF, ~residues 148–151)ADDF Cognitive Vitality report
PubChem CID: 56599151PubChem (name + formula match)
Molecular target: Competitive LIF antagonism (↓ LIF-STAT3, de-represses neurogenesis) + BDNF/TrkB → GSK-3β (↓ tau) — preclinicalPMID 20600002; PMID 34057082
CAS number: 1246751-68-7 (single-sourced; CAS↔CID link unverified)Wikipedia / ChemIDplus (CID itself verified by name+formula)
Not to be confused with: p21^Cip1/Waf1 (gene CDKN1A) — a different ~21 kDa cell-cycle proteinDisambiguation (distinct molecule)
Plasma half-life: Not established in humans (preclinical-only; the developer group reports >3 h in mice, but no human PK exists)Not establishedHalf-life curve →
Regulatory status: Not approved anywhere; research chemical, preclinical-onlyADDF report (no human trials on record)

Plain English

Mechanism

P021 is positioned as a small-molecule mimic of CNTF, and its proposed mechanism has two intertwined parts. First, it competitively blocks signaling by leukemia inhibitory factor (LIF) — a cytokine that normally suppresses the conversion of neural stem cells into new neurons. By getting in LIF's way, P021 is thought to release the brake on neurogenesis (the birth of new neurons). In cell culture it reduced LIF-driven STAT3 activation by about 30%.

Second, P021 raises BDNF (brain-derived neurotrophic factor), which switches on the TrkB → PI3K → Akt pathway and in turn inhibits GSK-3β, the main enzyme that adds harmful phosphate tags to the tau protein. This is the proposed route by which P021 reduces tau hyperphosphorylation in Alzheimer's models. The combined claimed effect in rodents is more new neurons, more synaptic connections, more BDNF, less abnormal tau, less soluble amyloid, and better memory.

Two honesty points anchor this section. The direction of these effects is consistent across the Iqbal group's rodent and cell work, but there is no human mechanistic confirmation of any of it. And the mechanism is context-dependent: in CDKL5-knockout mice it did NOT raise BDNF or rescue neurogenesis, suggesting the CNTF-style response it relies on can be absent in some genotypes. Present this as a well-characterized rodent mechanism, not a demonstrated human one.

Sources:PMID 20600002 PMID 25046994 PMID 34057082

Why people reach for it

Potential benefits

P21 is the neurogenesis story of the cognitive peptides — promising in rodents, untested in people. Here's what people pursue it for, kept honest about the evidence ceiling.

A pro-neurogenesis signal (in animals) — Its headline appeal: in mice and rats P21 reliably increases the birth of new neurons in the memory centre — the structural-cognition effect people pursue, though every result is rodent or cell-culture, never human.
Raises brain-growth factor BDNF (in animals) — Across the rodent work it raises BDNF and switches on the TrkB pathway — the growth-factor signal it is reached for, with the same animal-only caveat.
Memory support in aging/Alzheimer's models — In rodent models of aging and Alzheimer's it improved memory in maze and recognition tests and lowered the tau and amyloid changes those models show — reproducible within one lab's work, not a demonstrated human outcome.
Engineered to be brain-available — It was designed with an adamantane group specifically to survive the body and reach the brain — the reason people choose it as a neurogenic peptide, though its actual brain penetration is inferred from effects, not measured.
Stacks with the focus peptides — Because it works on the slow neurogenic axis rather than acute drive, people pair it with Semax or Selank for a near-term cognitive layer on top.

Sources:PMID 20600002 PMID 25046994 PMID 24702821 ADDF Cognitive Vitality

What people reach for P21 for, drawn from what the research reports — which is preclinical only (rodent and cell-culture, largely one lab; zero human trials) — and how it's used, not proven outcomes or medical claims.

Implied timing

Best time to dose

Implied best time

Morning

Most people take P21 in the morning, as a once-daily dose timed to daytime cognition — though there is no P21-specific timing data at all.

P21 is positioned as a daytime pro-cognitive / neurogenic compound, so a morning once-daily dose aligns the signal with waking-hour cognition the way the other cognitive peptides are used.
There is no peptide-specific timing study for P21 — and no human PK at all — so morning is general convention borrowed from the daytime nootropic pattern, not a measured rationale.
Some users mirror the Semax/Selank schedule (a single morning dose, cycled), which keeps a brain-active compound clear of sleep by default rather than for a proven sleep-interaction reason.
The developer group reports a >3 h half-life in mice, but no human pharmacokinetics exist, so the once-daily morning placement is a practical convention, not a dose-duration calculation.

No study establishes an ideal time of day for P21 — there is no human data of any kind, so this is reasoned from its daytime pro-cognitive positioning and how the cognitive peptides are used. As a rule of thumb most peptide dosing lands in the midday-to-evening window; for P21 the lean is the early edge of that — morning.

Sources:ADDF Cognitive Vitality

How to run it

Dosing & protocol

P021 is used here as a subcutaneous injection — the injectable research-peptide form the calculator is built for. The critical honesty axis: there is NO established human dose, NO human trial, and no pharmacokinetic data. The numbers below are community convention only, back-extrapolated from rodent data and peptide-community usage — not a validated human protocol. The animal studies used oral/diet delivery; that science stays in the cited dosing table below. This is how people actually run injectable P021 in research settings — not a prescription.

Preclinical only — zero human trials, no established human dose. The entire evidence base is rodent and cell-culture work, almost all from a single laboratory (Iqbal/IBR). BBB penetration is inferred from animal effects, not measured. Every number here is community convention extrapolated from rodent data, not a validated human figure. This page is about the CNTF-derived neurogenic peptide P021 (Ac-DGGLAG-NH₂) — not the p21/CDKN1A cell-cycle protein that shares the name.

Dose — no established human dose

No clinical trial has ever set a human dose. Community convention extrapolates from rodent data; treat every figure as a reference range, not a recommendation.

Community convention range:: 500–1,000 mcg (0.5–1 mg) subcutaneously once daily is the most commonly cited community range — derived by rough body-weight scaling from the rodent gavage dose of ~289 µg/kg/day, not from a human study. Some users cite up to 2 mg/day. No safety ceiling has been established.
Why this range is uncertain:: The workhorse rodent data used oral dietary delivery (60 nmol/g feed over months). Subcutaneous bioavailability in humans is entirely unknown. The community convention is a starting point, not evidence.
Starting point:: Many users begin at the lower end (500 mcg/day) for the first 1–2 weeks to observe tolerance before moving higher, given the complete absence of human safety data.

Subcutaneous administration

P021 is injected into subcutaneous fat; site, rotation, and timing are the actionable choices.

Injection site:: Abdomen (staying a couple of inches from the navel), outer thigh, or love-handle area. Rotate sites between doses — using the same spot repeatedly causes local irritation and can lead to lipohypertrophy (fatty lumps under the skin).
Measuring the dose:: Drawn on a U-100 insulin syringe from the reconstituted vial. At the standard 10 mg / 2 mL mix (5,000 mcg/mL): 500 mcg = 10 IU · 1,000 mcg = 20 IU. The on-page calculator adjusts for any vial size.
Time of day:: Morning is the common preference for a once-daily dose — see Best time to dose above. No peptide-specific timing data exists for P021; this is general convention.
Food window:: Subcutaneous injection bypasses the gut entirely, so there is no food-interaction issue; inject independent of meals.

Cycle & washout

No pharmacokinetic rationale exists for P021 cycling in humans — the following is community convention modeled on other neurogenic peptides.

Convention cycle:: 4–8 weeks of daily use, then reassess. Some protocols mirror Semax/Selank patterns of 4-week-on / 2-week-off; none is evidence-based for P021 specifically.
Washout:: 2–4 weeks off. No published data on P021 receptor desensitization or tolerance in humans exists; the washout is precautionary convention.
Long-course note:: Rodent studies ran P021 for up to 18 months with no observed weight loss, tumours, or pain signals. This cannot be read as a human safety guarantee — it is the only safety signal that exists, and it is from rodents.

Reconstitution at a glance

The on-page calculator does this live; the quick reference for a 10 mg vial:

Mixing:: 10 mg vial + 2 mL bacteriostatic water = 5,000 mcg per mL. On a 100-unit (1 mL) insulin syringe: 500 mcg = 10 IU · 750 mcg = 15 IU · 1,000 mcg = 20 IU.
Why 2 mL:: Keeps the per-unit dose in a measurable range on a standard U-100 syringe. Use the on-page calculator if your vial or target dose differs.

Sources:PMID 20600002 PMID 24702821 PMID 25046994 ADDF Cognitive Vitality

Substrate the signal needs

Nutritional cofactor precision

P021's whole premise is raising BDNF and triggering neurogenesis — the birth of new neurons. The useful cofactors are (1) the raw materials the brain needs to actually build those neurons and synapses, (2) the lifestyle inputs that independently drive BDNF, and (3) mitigants for any cost. Note: this is the CNTF-derived neurogenic peptide P021, not the p21/CDKN1A cell-cycle protein — nothing here is about cell division.

Reasoned from P021's CNTF/BDNF/neurogenesis mechanism and established neuroplasticity biology — not a P021 cofactor study. P021 itself has no human data; the cofactors below are general neuroplasticity nutrition reasoned onto that preclinical premise. Supplement doses are common community ranges.

Supply the substrate — what a neurogenic signal draws on

New neurons and their membranes are built from specific raw materials. These are the ones the BDNF/neurogenesis pathway consumes.

Omega-3 DHA · 1–2 g/day:: DHA (docosahexaenoic acid) is the primary structural fat in neuronal membranes — it is what new neurons are literally built from. Take 1–2 g DHA daily (from fish oil or algae oil), ideally with a fat-containing meal for absorption. This is the single most mechanism-aligned substrate for a neurogenic signal.
Choline · 400–600 mg/day:: The body converts choline into acetylcholine, the neurotransmitter central to memory encoding. As P021 (in theory) adds new neuronal wiring, choline keeps the transmitter-supply side stocked. CDP-choline (citicoline) or alpha-GPC are the preferred forms; take in the morning as choline is activating.
B6 · B9 · B12 (methylated):: The B-vitamin trio runs the methylation cycle that makes neurotransmitters and maintains myelin (the insulating sheath on nerve fibres). B9 (folate) and B12 deficiency visibly impairs cognitive function — keep these filled before asking a neurogenic signal to do heavy lifting. Use methylfolate + methylcobalamin forms; take in the morning with food.
Magnesium glycinate or threonate · 300–400 mg/day:: Magnesium gates the NMDA receptors that underlie synaptic plasticity — the mechanism by which new connections get formed and strengthened. Threonate has the best published brain-penetration data. Take in the evening; it is calming.

Amplify the BDNF signal P021 targets

These are the best-established non-pharmacological BDNF levers. A peptide that works by raising BDNF does less if these are absent.

Aerobic exercise · 30–45 min, 4–5×/week:: Zone 2 aerobic exercise (brisk walking, cycling, jogging at a conversational pace) is the most robustly proven BDNF-raising intervention in humans — the effect is acute (a single session raises serum BDNF within hours) and cumulative. If P021 is the signal, exercise is the amplifier.
Sleep · 7–9 hours, consistent schedule:: BDNF synthesis peaks during slow-wave sleep; chronic sleep restriction measurably lowers BDNF. Neurogenesis in the hippocampus is also largely nocturnal. Treat sleep as non-negotiable infrastructure, not a soft recommendation.
Lion's Mane mushroom · 500–1,000 mg/day (optional):: Lion's Mane (Hericium erinaceus) contains hericenones and erinacines that stimulate nerve growth factor (NGF) — a parallel neurotrophic signal to BDNF. Some users include it as an additional neurotrophic layer; evidence in humans is early-stage. Take with a meal.

Mitigate — minimal / data too thin

P021's rodent safety profile (18 months, no toxicity signals) and its mechanism do not flag obvious costs to offset. The main precaution is the unknown-unknowns of a preclinical-only compound.

No established cost to mitigate:: Unlike peptides with known side-effect profiles (e.g. water retention, cortisol effects), P021 has no human adverse-event record — because it has never been given to a human in a study. There is no cofactor that addresses a known P021 side effect, because no known side effects exist.
General CNS-health baseline:: Given the complete absence of human safety data, maintaining a solid baseline — adequate sleep, no concurrent untested CNS compounds, and periodic breaks (see cycle card) — is the closest thing to risk mitigation that reasonably applies.

Combinations + timing

Stacking notes + timing windows

P021 pushes the BDNF/neurogenesis axis. The best pairings come at the same neuroplasticity goal from a different angle — either a different neurotrophic route or a complementary cognitive mechanism. Stacking P021 with another BDNF-raiser would just push the same lever twice. Important: P021 itself has no human data, so every stack is doubly unproven — reasoned from mechanism and community convention, not studied.

User combinations reasoned from complementary mechanisms — no stack has been studied, and P021 has no human trial of its own. Every combination is doubly preclinical. Doses are community convention. This page covers the CNTF-derived neurogenic peptide P021 — not the p21/CDKN1A cell-cycle protein.

P021 + Semax

The most common P021 pairing — P021 is the neurogenic signal, Semax is the BDNF-modulator + focus sharpener from a different route.

Why it works:: Semax (ACTH 4-7 Pro-Gly-Pro) independently raises BDNF and modulates dopamine and serotonin systems — its effects on focus and mood are the most reproducible. P021 targets the LIF/STAT3 brake on neurogenesis and raises BDNF via TrkB/GSK-3β. Two different entry points on the BDNF axis, not the same lever twice: Semax is the acute cognitive sharpener; P021 is the slower structural neurogenic signal.
The protocol:: P021 500–1,000 mcg subcutaneously once daily. Semax 300–600 mcg intranasally once daily (or as two divided doses). Both are typically run on 4-week cycles with a 2-week break. Start each alone to establish your own baseline before combining.
Outcome:: The combination users reach for when the goal is both neurogenesis support (the P021 long-game) and acute cognitive clarity and mood (the Semax near-term effect). No head-to-head data exists; this is mechanism-reasoning plus community pattern.

P021 + Selank

A calmer cognitive pairing — P021 for the neurogenic signal, Selank for anxiolytic BDNF support and stress resilience.

Why it works:: Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) raises BDNF and has an established anxiolytic-without-sedation profile in Russian clinical work. Where Semax sharpens and activates, Selank calms without blunting. For users whose cognitive goal has an anxiety or stress-resilience component, Selank is the more appropriate angle than Semax; the BDNF contribution is additive, not redundant, because the signaling route differs.
The protocol:: P021 500–1,000 mcg subcutaneously once daily. Selank 300–750 mcg intranasally once or twice daily. Run each on its own 4-week cycle discipline. As with all P021 combinations, the stack carries no human safety data.
Outcome:: Reached for on goals that combine neuroplasticity support with stress or anxiety management — where adding a stimulating BDNF peptide (Semax) would not be the right fit.

P021 + substrate stack (DHA · choline · magnesium)

Not a peptide-peptide stack — pairing P021 with the neurotrophic substrate cofactors as a deliberate protocol, not just as background nutrition.

Why it works:: P021's proposed action is to increase the rate of new neuron formation (neurogenesis) and synaptic connection. Those new neurons are built from DHA. Their connections require choline-derived acetylcholine for function. Their plasticity runs on NMDA receptors gated by magnesium. Running the three cofactors as a deliberate protocol — rather than hoping diet covers them — ensures the substrate is there when the neurogenic signal fires. Different lever entirely (structural raw material vs. signaling).
The protocol:: P021 500–1,000 mcg subcutaneously once daily. DHA 1–2 g/day with a fat-containing meal. Alpha-GPC or CDP-choline 300–500 mg in the morning. Magnesium glycinate or threonate 300–400 mg in the evening.
Outcome:: The substrate-first approach for users who want to maximise whatever neurogenic signal P021 is providing — insurance that the building materials are present. Low additional risk (all are nutritional compounds); highest mechanism-alignment of any P021 combination.

Reconstitution math

Reconstitution calculator

Calculated for a 1 mL U-100 insulin syringe (100 units/mL).

Peptide per vial

BAC water added

Desired dose

Units per dose

Draw to this mark on a U-100 syringe

Volume per dose: 0.2 mL
Doses per vial: 10
Concentration: 5 mg/mL

One vial lasts

Daily: 10 days
Every other day: 20 days
5×/week: 14 days

Research use only. Not for human consumption. Outputs are reference values based on research literature — verify all measurements independently.

From the studies

Side effects from research

The honest summary is that there is no human safety data for P021 — it has never been assessed in people, as the ADDF report states directly. With no human trials, there is no systematic adverse-event record, no dosing ceiling, and no long-term human safety information.

The available safety signals are rodent-only and, within that corpus, favorable: dosing for up to 18 months in mice produced no weight loss, no tumours, and no signs of pain or distress, and notably P021 lacks the appetite-suppressing toxicity that sank full-length CNTF — which is the whole reason a fragment was used. One review raised the hypothetical concern that an injected peptide like this could provoke anti-P021 antibody formation, though none has been observed.

The caveat that matters: every one of these 'good safety' observations is from rodents, mostly from a single lab, and cannot substitute for the human Phase 1 safety data that simply does not exist. P021's safety in people is unknown.

Sources:ADDF Cognitive Vitality PMID 28655344

As reported in literature

Research dosing ranges

These are the doses that actually exist in the literature — and they are all preclinical, almost all from one lab (Iqbal/IBR). There is no human dose row to show, because no human study has ever been run. The decisive independent source is the ADDF Cognitive Vitality report, which confirms there are no human trials, no observational studies, and no established human dose. Doses below are rodent figures with no human translation.

Dose	Route	Model	Outcome	Sources:
25 nmol/day (SC depot)	SC implant (mice)	Wild-type mice — first in-vivo P021 study (Li 2010)	↑ object-recognition & spatial memory, ↑ neurogenesis (new DG neurons), ↑ synaptic proteins; in-vitro ↓ LIF-STAT3 ~30% — RODENT/cell data	PMID 20600002
≈289 µg/kg/day	Oral gavage (aged rats)	Aged Fisher rats — cognitive-aging rescue (Bolognin 2014)	↑ neurogenesis, ↑ BDNF/TrkB/pCREB, restored synaptic proteins; maze improvement modest — RODENT data	PMID 24702821
60 nmol/g feed	Oral / diet (mice)	3xTg-AD Alzheimer's mice — disease-modifying study (Kazim 2014)	↓ phospho-tau, ↓ soluble amyloid, ↑ BDNF, neurogenesis restored to wild-type, memory restored — RODENT data	PMID 25046994
60 nmol/g feed	Oral / diet (mice)	3xTg-AD mice from 3 mo, up to 18 mo (Baazaoui & Iqbal 2017)	Rescued dendritic/synaptic deficits, neurogenesis ~4× vehicle, reversed cognitive impairment (behavior n=14–20/grp) — RODENT data	PMID 28655344
Oral diet, postnatal	Oral / diet (mice)	3xTg-AD mice — early-postnatal prevention (Wei 2021)	Prevented cognitive impairment, restored hippocampal BDNF; notes NO study has directly assayed brain P021 levels — RODENT data	PMID 34057082
No human dose exists	—	Humans — P021	ZERO human trials, ZERO observational studies, no established human dose, no human safety data (per ADDF report)	ADDF Cognitive Vitality

Quick answers

Frequently asked

Is P021 the same as the p21 cancer protein?

No. This P021 is a small CNTF-derived neurogenic peptide (Ac-DGGLAG-NH₂). The famous 'p21' from cancer biology is a completely different, much larger cell-cycle / tumour-suppressor protein encoded by the gene CDKN1A. They share a name but are unrelated molecules.

Has P021 been tested in humans?

No. There are zero human clinical trials, zero observational studies, no established human dose, and no human safety data. Every result comes from mice, rats, or cell cultures, and almost all of it from a single laboratory.

Does it cross into the brain?

Probably, but it has never been directly measured. P021 was engineered with an adamantane group specifically to cross the blood–brain barrier, and its effects on the brain in animals imply it gets in — but no study has quantified how much actually reaches the brain, and the ADDF report lists its blood–brain-barrier penetration as 'not documented.'

What does the animal evidence actually show?

In rodent models of Alzheimer's and aging, P021 increases neurogenesis and BDNF, lowers abnormal tau and soluble amyloid, restores synaptic markers, and improves memory. These effects are reproducible within the Iqbal group's work, but independent-lab replication is thin and one test in a different genotype (CDKL5-deficient mice) was largely negative.

Is there an established dose?

Not for humans. The only doses that exist are rodent doses (such as 60 nmol per gram of feed in Alzheimer's-model mice). The ADDF report states a human dose has not been established, and any community figure has no clinical basis.

Is P021 banned in sport?

It is not named individually on the 2026 WADA Prohibited List, but it could plausibly fall under the S2.2 growth-factor catch-all (which covers agents affecting 'regenerative capacity') because it is a CNTF-derived peptide that drives neural regeneration and BDNF. This is an interpretation, not an explicit listing — an athlete should treat it as a risk and seek a formal ruling.

Primary sources

References

PMID 20600002Li et al., FEBS Lett 2010 — adamantane neurotrophic peptides improve learning/memory & neurogenesis in mice (foundational; defines P021/Ac-DGGLAG-NH₂)
PMID 24702821Bolognin et al., Neurobiol Aging 2014 — rescue of cognitive-aging by a neurogenic/neurotrophic compound (aged rats)
PMID 25046994Kazim et al., Neurobiol Dis 2014 — disease-modifying effect of chronic oral P021 in 3xTg-AD mice
PMID 28655344Baazaoui & Iqbal, Alzheimers Res Ther 2017 — prevention of dendritic/synaptic deficits with a neurotrophic compound (3xTg-AD mice)
PMID 34057082Wei et al., J Alzheimers Dis 2021 — early-postnatal neurotrophic treatment prevents Alzheimer-like behavior (notes brain P021 levels never directly assayed)
ADDF Cognitive VitalityAlzheimer's Drug Discovery Foundation — Cognitive Vitality report on P021 (authoritative secondary; 'no studies have tested P021 in humans')
WADA 2026WADA 2026 Prohibited List — S2.2 growth-factor 'regenerative capacity' catch-all; P021 not explicitly named (status by inference)

Research use only · Not medical advice · Updated 2026-06-01