CognitiveTP-7Thr-Lys-Pro-Arg-Pro-Gly-Pro

Selank

Synthetic tuftsin analog · anxiolytic

Selank is a synthetic seven-amino-acid peptide built on tuftsin — a small natural immune-signaling fragment of the antibody molecule — with a stabilizing Pro-Gly-Pro tail added so it resists rapid breakdown, the same design used for Semax. In Russia it is a registered prescription anxiolytic: an intranasal solution for generalized anxiety disorder and neurasthenia. Its best-supported molecular action, shown in human serum, is that it slows the enzymes that break down the body's own enkephalins, raising enkephalin levels; additional effects on brain growth factors (BDNF), GABA-related genes, and serotonin metabolism are documented but come from rodents. The principal human study compared Selank to a benzodiazepine (medazepam) in about 62 patients and found comparable calming effect plus an anti-fatigue benefit. Two honest caveats define this peptide: the clinical evidence is overwhelmingly Russian, older, small, and conducted by the drug's developers rather than independently replicated by Western trials; and it is not FDA- or EMA-approved, with no validated human plasma half-life published and no primary-source evidence that it enhances cognition in healthy people.

The short version

Selank is a short synthetic peptide — seven amino acids — based on tuftsin, a tiny natural fragment of the antibody molecule that helps regulate the immune system. As with Semax, researchers added a small tail (Pro-Gly-Pro) so the body's enzymes can't break it down as quickly.

It is a real, approved medicine — but only in Russia, where it is sold as a nasal spray and prescribed for anxiety (generalized anxiety disorder) and a fatigue-type condition called neurasthenia. Outside Russia it has no approval and is sold as a research chemical.

The most solid piece of its biology, shown in human blood, is that it slows the enzymes that destroy the body's own natural calming/pain-relief molecules (enkephalins), letting their levels rise. Other reported effects — on brain growth factor (BDNF), on GABA-related genes, on serotonin — are real findings but come from rats, not people.

Two honest caveats. The human evidence is almost all Russian, older, in small studies run by the people who developed the drug, and not independently repeated by Western trials. And despite the marketing, there is no solid primary-source study showing Selank makes healthy people smarter, no reliable published figure for how long it lasts in the body, and the popular 'works like a benzo but with no downsides' line goes beyond what one small trial actually showed.

Molecular identity

Specs

Molecular weight: 751.9 g/mol
Molecular formula: C₃₃H₅₇N₁₁O₉
Monoisotopic mass: 751.43407 Da
CAS / UNII: 129954-34-3 · TS9JR8EP1G
PubChem CID: 11765600

Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP) — 7 AA heptapeptidePubChem CID 11765600
Structure / class: Synthetic tuftsin analog — tuftsin (Thr-Lys-Pro-Arg) + C-terminal Pro-Gly-Pro stabilizing tail; anxiolytic neuropeptide (dev code TP-7)PubChem CID 11765600; research literature
Water solubility: Freely water-soluble; highly hydrophilic (computed XLogP −6.1, TPSA 322 Å²)PubChem CID 11765600 (computed properties)
Molecular target: Inhibits enkephalin-degrading enzymes of human serum (IC50 ~20 µM), raising endogenous enkephalins; rodent BDNF + GABAergic-gene effects (no direct GABA-A binding). No classic single receptorPMID 11443939 (human-serum enkephalinase inhibition)
Half-life: No validated human plasma half-life published; labile parent peptide, biodegradation products characterized in rodent (tritium-labeled)PMID 16637290 (Selank biodegradation); Not established for humans
Origin: Synthetic tuftsin (Thr-Lys-Pro-Arg) + C-terminal Pro-Gly-ProResearch literature
Regulatory status: Registered prescription anxiolytic in Russia (intranasal 0.15% solution); not FDA/EMA-approvedRussian drug registry; research literature

Plain English

Mechanism

Selank is a synthetic analog of tuftsin (Thr-Lys-Pro-Arg), a naturally occurring tetrapeptide (four–amino-acid chain) cleaved from the Fc region of the immunoglobulin G heavy chain — a piece snipped from the tail end of the body's main antibody — with immunomodulatory (immune-system-regulating) activity. Selank keeps the tuftsin sequence and adds a C-terminal Pro-Gly-Pro (PGP) tripeptide (a three–amino-acid tail on the end); that PGP cap is the defining modification, conferring resistance to the peptidases (the enzymes that chop up peptides) that rapidly destroy native tuftsin and prolonging the molecule's activity.

Its best-supported molecular mechanism is established in human tissue: Selank inhibits the enkephalin-degrading enzymes of human serum, slowing the breakdown of endogenous enkephalins — the body's own natural calming and pain-relieving molecules — (with a half-maximal inhibitory concentration, the amount needed to slow the enzymes by half, on the order of 20 µM). In the clinical anxiety study, Selank treatment was associated with raised serum enkephalin levels, and baseline enkephalin tracked inversely with symptom severity (the lower someone's starting enkephalin, the worse their symptoms) — consistent with this enkephalin-stabilizing mechanism. This is a genuine tuftsin-lineage effect and the most defensible part of its pharmacology (how the drug acts in the body).

A broader set of effects is documented in rodent brain and should be read as preclinical (animal-stage, pre-human): in rats, intranasal (nasal-spray) Selank raised BDNF (brain-derived neurotrophic factor, a protein that helps brain cells grow and survive) mRNA — the gene's working copy — in the hippocampus (a memory and mood region), altered the expression of genes involved in GABAergic neurotransmission (the brain's main calming signaling system) in the frontal cortex, and changed the metabolism of serotonin (a key mood chemical) in the brainstem (an effect tuftsin itself did not reproduce). A single intranasal dose produced broad transcriptomic shifts (wide changes in which genes were switched on or off) across hippocampus and spleen, several of them inflammation-related. None of these CNS (central nervous system, i.e. brain and spinal cord) mechanisms has equivalent human tissue data.

Consistent with its tuftsin origin, Selank also shows immunomodulatory (immune-regulating) activity in humans: in patients with anxiety-asthenic disorders (anxiety combined with fatigue/weakness) and in peripheral blood cells it suppressed interleukin-6 expression — turning down a key inflammation-signaling protein — and shifted the balance of Th1/Th2 cytokines (the two arms of immune-cell messengers that steer the type of immune response). A practical honesty note: most of this mechanistic work originates from a single Russian research network (the Institute of Molecular Genetics, Russian Academy of Sciences) and has not been independently replicated by Western laboratories.

Sources:PMID 11443939 PMID 18454096 PMID 18841804 PMID 26924987 DOI 10.1134/S1607672910010023 PMID 18577961 PMID 19803361

Why people reach for it

Potential benefits

Selank is the calm half of the Russian nootropic tradition — anxiolytic without the sedation. Here's what people reach for it for.

Calm focus without drowsiness — Its headline appeal. In the human comparison study Selank matched a benzodiazepine's anxiety-reducing effect while staying non-sedating — calm that doesn't dull you, the reason people use it during the working day.
Take-the-edge-off for a demanding moment — Because it is reported to be fast-acting and non-sedating, people reach for it situationally before a stressful or high-stakes task — a presentation, an exam, a social event — not only as a daily course.
An anti-fatigue lift alongside the calm — The same trial reported an antiasthenic (anti-fatigue) benefit on top of the anxiolytic effect — calm with a small energy lift rather than a sedative drag.
Eases an anxious, racing mind — Its best-supported molecular action, shown in human serum, is slowing the breakdown of the body's own calming enkephalins; in rodents it also nudges GABA-related genes and serotonin — the basis for the quieter-mind effect people pursue.
The calm partner to a focus peptide — Pairs cleanly with Semax — Selank supplies the calm, Semax the drive, the canonical Russian focus-plus-calm combination.

Sources:PMID 11443939 PMID 18454096 PMID 18841804 PMID 26924987

What people reach for Selank for, drawn from what the research reports (one small Russian human trial; brain mechanism from rodents) and how it's used — not proven outcomes or medical claims.

Implied timing

Best time to dose

Implied best time

Daytime (as needed)

Most people take Selank during the day, when the calm-focus effect is wanted — often on a schedule, sometimes situationally before a demanding task.

Selank is non-sedating — users report a calm-without-drowsiness window of several hours — so it is used during waking hours for daytime composure, not as a sleep aid the way a sedative would be.
Because it is reported to act fast and not sedate, it suits situational use: a single daytime dose ahead of a stressful or high-stakes moment is a common pattern, on top of (or instead of) a fixed daily schedule.
For split dosing, morning plus midday is the usual placement; very late dosing is generally avoided by anyone sensitive to its mild cognitive activation, to keep it clear of sleep.
No validated human plasma half-life is published, so the timing is reasoned from its non-sedating anxiolytic profile and how it's used, not from a measured duration of action.

No study establishes an ideal time of day for Selank — this is reasoned from its non-sedating anxiolytic mechanism and how it's actually used. As a rule of thumb most peptide dosing lands in the midday-to-evening window; for Selank the lean is the daytime side of that, and it can also be used situationally.

Sources:PMID 18454096 PMID 16637290

How to run it

Dosing & protocol

Selank is intranasal-primary — the registered Russian drug is a 0.15% nasal solution, and nose-to-brain delivery via the olfactory and trigeminal nerves is the route the human evidence is built on. Subcutaneous injection is a second-route option used by the research-peptide community with the reconstituted powder. Both routes are covered here. Nothing below is a medical recommendation — it is community and practitioner convention drawn from the Russian registration and the cited evidence.

Mostly Russian clinical evidence: Selank is an approved drug in Russia, but the human trial is a single small developer-run study, not an independent Western RCT. Community dosing for both routes is extrapolated from that registration. Every number here is a usage pattern, not proven human dosing.

Tiered dose ranges

Community protocols scale the daily dose to the intensity of the anxiety or stress context.

Low / first use:: 250 mcg/day — starting dose to assess individual response; intranasal or subcutaneous.
Standard:: 250–500 mcg/day — the community baseline for ongoing anxiolytic goals; the most-cited range drawn from the Russian registration and vendor community figures.
Higher / acute:: 500–750 mcg/day — occasionally used for intense acute-anxiety periods, though not established by any trial; typically held to the length of a single short course.

Administration — intranasal + subcutaneous

Intranasal is the primary and historically validated route; subcutaneous is the second option with the reconstituted research powder.

Intranasal — how:: 2–3 drops (or one spray) per nostril, 1–3 times per day, for a total of 250–500 mcg/day. Sniff gently after application to draw the solution toward the olfactory epithelium at the roof of the nasal cavity — this is the nose-to-brain delivery surface, bypassing the blood-brain barrier via the olfactory and trigeminal nerve pathways.
Intranasal — concentration math:: The registered Russian formulation is 0.15% (1.5 mg/mL). A standard research-peptide reconstitution at 5 mg vial + 3.3 mL bacteriostatic water also yields approximately 1.5 mg/mL — matching the registered concentration. Each drop is roughly 30–40 mcg; 3 drops per nostril twice daily ≈ 360–480 mcg/day.
Subcutaneous — site + rotation:: Abdomen (two inches clear of the navel), outer thigh, or flank. Rotate sites each dose to avoid local irritation.
Subcutaneous — measuring the dose:: Drawn on a U-100 insulin syringe from the reconstituted vial; using the calculator default (10 mg vial + 2 mL BW = 5,000 mcg/mL): 250 mcg = 5 IU · 500 mcg = 10 IU. Adjust the mix for your vial size using the on-page calculator.
Time of day:: Daytime — see Best time to dose above. Selank is non-sedating, and users report a calm-without-drowsiness window of several hours, so it can also be taken situationally before a demanding task. For split dosing (twice daily), morning + midday works well; avoid late evening if you are sensitive to cognitive activation.
Food window:: No meaningful food interaction for either route; take independently of meals.

Cycle & washout

The Russian registration and human study were built on short courses — that is the grounding for cycling rather than continuous use.

Standard cycle:: 10–14 days of daily use — mirrors the registered clinical course length. This is the only pattern with any human-registration backing.
Extended community cycle:: Some users run 3–4 week courses, reverting to the registered short-course rationale: the parent peptide is enzymatically labile (breaks down quickly) while its central effects appear to outlast it, so prolonged continuous dosing adds compounding exposure without demonstrated added benefit.
Washout:: Take 2–4 weeks off between courses. There is no long-term independent safety database for Selank, so the conservative pattern is defined short blocks.
Situational / on-demand:: Because Selank is reported to be fast-acting and non-sedating, some users dose acutely around high-stress events — 1–3 days of use rather than a full course. This is user extrapolation, not registration-backed.

Reconstitution at a glance

The on-page calculator handles any vial size; quick reference for the intranasal-concentration match:

Intranasal match (1.5 mg/mL):: 5 mg vial + 3.3 mL bacteriostatic water = 1,500 mcg/mL ≈ registered Russian concentration. Each nasal drop (~30–40 mcg): 2–3 drops/nostril gives 120–240 mcg per session.
Standard injectable mix:: 10 mg vial + 2 mL bacteriostatic water = 5,000 mcg/mL. On a U-100 syringe: 250 mcg = 5 IU · 500 mcg = 10 IU · 750 mcg = 15 IU.

Sources:PMID 18454096 PMID 16637290 PMID 11443939

Substrate the signal needs

Nutritional cofactor precision

Selank's mechanism touches three calming-neurotransmitter axes — enkephalin stability, GABAergic tone (in rodents), and serotonin metabolism (in rodents). The useful cofactors supply the substrates those systems run on, or amplify the same calming signal from a complementary angle. Selank is notably well-tolerated, so there is no meaningful cost to mitigate.

Reasoned from Selank's GABA/serotonin/enkephalin mechanism plus general calming-neurotransmitter nutrition — not a Selank cofactor study. The rodent CNS effects are a single Russian network's data; treat this as informed reasoning, not cofactor proof.

Supply the calming-neurotransmitter substrate

Give the serotonin and GABA systems what they are built from.

Magnesium glycinate — 300–400 mg at night:: Magnesium supports GABA-receptor tone and dampens the excitatory NMDA receptor — a direct substrate for the calming axis Selank is reported to nudge. Glycinate form crosses the blood-brain barrier well and is the least likely to cause GI upset.
L-theanine — 100–200 mg with each Selank dose:: Promotes alpha-wave brain activity (a calm-but-alert state) without sedation — mechanistically synergistic with Selank's anxiolytic profile, working the same calm-signal lever from a complementary angle. Stack timing: take together with the morning intranasal or injection.
Tryptophan or 5-HTP — tryptophan 500 mg at night / 5-HTP 50–100 mg at night:: Serotonin is synthesized from tryptophan, and Selank is reported to alter serotonin metabolism in rodent brainstem. Supplying the precursor supports that arm. 5-HTP is one step closer to serotonin and more potent — start low. Take at night, away from Selank dosing, to avoid any theoretical serotonin-system over-stimulation.

Amplify the signal

P5P (activated B6) is the rate-limiting cofactor for both GABA synthesis and the tryptophan→serotonin conversion.

Pyridoxal-5-phosphate (P5P) — 25–50 mg in the morning:: The active form of vitamin B6 is required by the enzymes that make both GABA (glutamate decarboxylase) and serotonin (aromatic L-amino acid decarboxylase). Deficiency creates a bottleneck in both pathways simultaneously — P5P removes that bottleneck. Standard B6 (pyridoxine) works but converts more slowly; P5P is the direct coenzyme form.

Mitigate the cost

Selank has an unusually clean tolerability profile — no dependence mechanism, no sedation, no significant reported side effects in the human trial. There is no major cost to offset.

Hydration + electrolytes if using intranasal:: Nasal delivery can mildly dry the nasal mucosa with repeated use. Staying well-hydrated and using a saline nasal rinse between courses (not simultaneously) keeps the delivery surface healthy. This is a practical comfort measure, not a pharmacological cofactor.

Combinations + timing

Stacking notes + timing windows

Selank's defining property is anxiolytic calm without sedation. The best pairings add a different lever — cognitive drive, neuroplasticity, or deeper neuromodulation — rather than doubling the calming signal. Pairing two anxiolytics pushes the same lever twice: redundant, not synergistic.

Combinations reasoned from complementary mechanisms — not head-to-head studied stacks, and Selank's own CNS effects are largely Russian rodent data. Doses are community convention; 'commonly combined for' describes where users reach, not a proven indication.

Selank + Semax

The anchor pairing — calm and drive on separate levers. The most-cited Russian nootropic combination.

Why it works:: Semax drives cognitive activation and BDNF expression (the neurotrophic/growth side); Selank provides the anxiolytic balance — reducing the edge or anxiety that Semax's stimulating profile can introduce. Same Pro-Gly-Pro design family, opposite functional poles: calm + drive, not the same signal twice.
The protocol:: Selank 250–500 mcg/day intranasal (or subcutaneous) + Semax 300–600 mcg/day intranasal (or subcutaneous), run on the same short-course schedule (10–14 days). Intranasal: administer Semax in one nostril, Selank in the other, or alternate morning/afternoon between the two. Subcutaneous: separate sites or co-inject.
Outcome:: Commonly combined for focus under pressure, anxious-mind quiet, and productivity goals where cognitive activation alone tips into restlessness.

NA-Selank-Amidate as a swap, not a stack

A longer-acting variant of Selank — not a partner, a different molecule with a similar mechanism and extended duration.

Why it is a swap:: NA-Selank-Amidate (N-acetyl Selank amidate) carries the same tuftsin-analog core with N-acetyl and C-terminal amide modifications that slow enzymatic degradation further — extending the anxiolytic window beyond standard Selank. Running both simultaneously is redundant (same mechanism, doubled exposure). Use one or the other for a given course.
The protocol:: NA-Selank-Amidate is typically dosed lower (100–300 mcg/day intranasal or subcutaneous) because of the extended activity. Choose it when you want a longer-lasting effect from fewer administrations per day.
Outcome:: Commonly reached for by users who want once-daily dosing or find standard Selank's duration too short for their use case.

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: 0.06 mL
Doses per vial: 33
Concentration: 5 mg/mL

One vial lasts

Daily: 33 days
Every other day: 66 days
5×/week: 46 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

Russian clinical reports describe intranasal (nasal-spray) Selank as generally well-tolerated and non-sedating (not causing drowsiness), and the comparison study found it matched the benzodiazepine (a class of sedative anti-anxiety drugs, e.g. Valium) medazepam's anxiolytic (anxiety-reducing) effect while adding an anti-fatigue benefit rather than causing sedation. The registered use is short courses (about 10–14 days) rather than continuous use.

Two honesty caveats belong with that picture. The safety data are limited, short-term, small-sample, and generated by the drug's developers — there is no large, independent (non-Russian) safety database and no long-term pharmacovigilance (ongoing monitoring of a drug's safety after release). And the widely repeated claim that Selank is anxiolytic 'with no dependence or withdrawal' (no addiction and no symptoms on stopping) rests on a single small trial; the absence of dependence has not been established by dedicated, independent discontinuation studies (studies that specifically test what happens when people stop), so it should be read as not-yet-demonstrated rather than proven.

Selank is not an FDA- or EMA-approved medicine; outside Russia it is sold as a research chemical. This page presents the research literature only and makes no therapeutic claims.

Sources:PMID 18454096

As reported in literature

Research dosing ranges

These are the doses and formulations actually used in the published studies and the Russian drug registration — the evidence the practical patterns above lean on, shown separately so research data is never mistaken for a recommended human dose, and this page makes no therapeutic or how-to claim. Two cautions frame the table. First, the human evidence comes from a small, single-center Russian study run by the drug's developers, not a Western placebo-controlled trial; the exact registered milligram-per-day schedule is not pinned to a public primary document, so only the route and formulation strength (0.15% intranasal solution) are stated rather than a specific human dose. Second, the rodent doses (in µg/kg, micrograms per kilogram of body weight) are mechanism experiments in animals and do not translate to a human dose. Vendor 'protocols' (e.g. 250–500 µg/day) are anecdotal and are not presented here as established.

Dose	Route	Model	Outcome	Sources:
Course of intranasal Selank vs medazepam	Intranasal	Human — GAD & neurasthenia (n=30 Selank vs 32 medazepam)	Anxiolytic effect comparable to the benzodiazepine medazepam, plus an antiasthenic/anti-fatigue effect; raised serum enkephalin	PMID 18454096
0.15% intranasal solution	Intranasal	Human — registered Russian drug (GAD / neurasthenia)	Marketed formulation strength; short courses (≈10–14 days) rather than continuous use
200 µg/kg, single dose	Intranasal	Rat — hippocampus & spleen (mechanism)	Broad transcriptomic changes; chronic 5-day dosing altered a further set of genes	DOI 10.1134/S1607672910010023
Intranasal	Intranasal	Rat — hippocampus (mechanism)	Increased BDNF mRNA expression in vivo	PMID 18841804
Selank ± diazepam	Intraperitoneal	Rat — elevated-plus-maze, chronic mild stress	Selank enhanced diazepam's anxiety-reducing effect under chronic mild stress	PMID 28280289

Quick answers

Frequently asked

What is Selank?

Selank is a synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro; developmental code TP-7) based on the natural immune-signaling tetrapeptide tuftsin, with a Pro-Gly-Pro tail added for stability. In Russia it is a registered intranasal anxiolytic for generalized anxiety disorder and neurasthenia; outside Russia it is not approved and is sold as a research chemical.

How does Selank work?

Its best-supported molecular action, shown in human serum, is that it slows the enzymes that break down the body's own enkephalins, allowing enkephalin levels to rise. In rodents it also raises brain growth factor (BDNF) and influences GABA-related genes and serotonin metabolism, and in humans it has immune effects (lowering interleukin-6) — but the brain mechanisms are animal data, not human tissue findings.

Is Selank as good as a benzodiazepine?

One small Russian study (about 62 patients) found Selank's calming effect comparable to the benzodiazepine medazepam, with an added anti-fatigue benefit. That is a genuine but limited result: it is a single, small, single-center trial run by the drug's developers, not an independently replicated Western trial. The popular claim that it works 'like a benzo but with no dependence or withdrawal' goes beyond what that one study can establish.

Does Selank improve cognition in healthy people?

There is no primary-source clinical trial showing that Selank enhances cognition in healthy adults. The nootropic reputation rests on rodent gene-expression and BDNF studies and on the anti-fatigue arm of one anxiety trial — not on healthy-human cognition data.

What is Selank's half-life?

No validated human plasma half-life has been published. The parent peptide is broken down by enzymes fairly quickly (its degradation fragments have been characterized), while its central effects appear to outlast it. The specific numbers quoted online (often '2–3 minutes') are not traceable to a primary pharmacokinetic study.

Is Selank approved or banned in sport?

It is a registered prescription drug in Russia but is not FDA- or EMA-approved. It is not specifically named on the WADA Prohibited List, but because it lacks approval by major regulators it may fall under WADA's S0 'non-approved substances' clause — athletes should treat it as potentially prohibited and consult their anti-doping authority. The specific classification is not independently confirmed here.

Primary sources

References

PubChem CID 11765600PubChem CID 11765600 (Selank / TP-7, tuftsin analog)
PMID 11443939Kost et al., Bioorg Khim 2001 (Semax & Selank inhibit enkephalin-degrading enzymes of human serum)
PMID 18454096Zozulya et al., Zh Nevrol Psikhiatr 2008 (principal human GAD/neurasthenia trial; Selank vs medazepam, n=62)
PMID 18577961Uchakina et al., Zh Nevrol Psikhiatr 2008 (immunomodulation in anxiety-asthenic patients; IL-6 suppression, Th1/Th2 shift)
PMID 19803361Semenova et al., Eksp Klin Farmakol 2009 (Selank vs tuftsin on brain serotonin metabolism, PCPA rats)
PMID 18841804Inozemtseva et al., Dokl Biol Sci 2008 (intranasal Selank regulates BDNF expression in rat hippocampus in vivo)
PMID 26924987Volkova et al., Front Pharmacol 2016 (Selank affects expression of genes in GABAergic neurotransmission, rat)
DOI 10.1134/S1607672910010023Kolomin et al., Dokl Biochem Biophys 2010 (transcriptomic response of rat hippocampus & spleen to Selank, 200 µg/kg)
PMID 16637290Zolotarev et al., Bioorg Khim 2006 (tritium-labeled Selank biodegradation; degradation products identified)
PMID 28280289Kasian et al., Behav Neurol 2017 (Selank enhances diazepam's anxiolysis under chronic mild stress, rat EPM)

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