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Synthetic nootropics & research compounds

IDRA-21

IDRA-21 (7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide)

IDRA-21 is an experimental synthetic AMPA receptor modulator, not a routine supplement. The cognition signal is animal and non-human-primate evidence, with no established human dose or clinical benefit. Safety concern is meaningful because AMPA potentiation can worsen excitatory-injury contexts such as ischemia or seizures in animal models.

Memory SupportLearning SupportGlutamatergicIsolated CompoundSyntheticMostly Animal EvidenceMostly In Vitro Evidence
Updated August 2026/5 min read/11 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

What IDRA-21 is

4

IDRA-21 is a synthetic benzothiadiazine compound studied as an ampakine-like positive allosteric modulator of AMPA receptor signaling. It belongs in a research-compound context, not a normal nutrient, botanical, or routine supplement context.

Human evidence boundary3
The strongest cognition evidence is animal and non-human-primate work. I did not find peer-reviewed human efficacy or dose-finding trials for IDRA-21, so the page should not imply a validated human nootropic dose.
02

Names, aliases and forms

Spelling variantsIDRA 21; IDRA21
Iupac Name7-chloro-3-methyl-3,4-dihydro-2H-1lambda6,2,4-benzothiadiazine 1,1-dioxide
Chemical Name7-Chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine S,S-dioxide
Molecular FormulaC8H9ClN2O2S
InchikeyVZRNTCHTJRLTMU-UHFFFAOYSA-N
Pubchem Cid3688
Cas Number22503-72-6
Regulatory NameUNII 689UW7PT68
Research CodeCHEMBL77862
03

Mechanisms of action

AMPA receptor desensitization

4

IDRA-21 attenuates AMPA receptor desensitization, which can increase excitatory synaptic strength. That mechanism explains the interest in memory tasks, but it also makes safety context unusually important.

LTP and receptor complexity

6

In hippocampal slices, IDRA-21 facilitated long-term potentiation under some stimulation paradigms. Separate cell work also found A glutamate-linked receptor involved in nerve-cell signaling.Source-mediated effects, so IDRA-21 should not be framed as a simple one-target memory aid.

04

Potential effects and evidence map

IDRA-21 has mechanistic and preclinical cognition evidence: rat maze/passive-avoidance studies, hippocampal slice LTP work, and non-human-primate delayed matching or recognition-memory tasks. I did not find peer-reviewed human efficacy or dosing trials for IDRA-21, so any nootropic claim should stay animal/primate-limited.

Effect domainMagnitudeGrade
Memory / learning8
UnknownConfidence: Low

Improved memory or learning-task performance in animal and non-human-primate studies, but human benefit is not established.

Note Do not convert the primate or rat findings into a human nootropic claim.

2/5
D
Focus / attention11
UnknownConfidence: Low

Task-performance signals are limited to controlled animal/primate paradigms rather than human attention trials.

Note The macaque work used a high-demand visual recognition-memory task, not a consumer attention endpoint.

1/5
D
05

Typical dosages and timing

Human dose8Not established

Published studies used animal or non-human-primate dosing such as 4-120 umol/kg in rats, 3 or 5.6 mg/kg in patas monkeys, and 0.15-10 mg/kg in rhesus monkeys. Those are not human supplement doses and should not be converted into self-use instructions.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
Non-human-primate task window8

One rhesus monkey delayed-matching study reported task effects maintained to 48 hours after a single oral dose. Human onset, duration, The time for blood levels to fall by half during the final elimination phase.Source, and appropriate spacing remain unknown.

07

Safety, side effects and risk profile

Experimental compound boundary7
IDRA-21 lacks a normal human safety profile. Its AMPA-positive mechanism may be relevant to cognition, but excessive AMPA activation is also part of injury biology, so absence of human adverse-event data is not reassuring.
Legal / regulatory risk3
Confidence: Medium

Legal status varies by jurisdiction and time; checked US-oriented sources do not show a normal approved-use or registered compound-trial path for IDRA-21.

Note Regard product listings as research-compound offers rather than routine dietary-supplement guidance, and verify local rules before any purchase decision.

4/5
C
Interaction risk7
Confidence: Medium

AMPA potentiation raises nervous-system risk in excitatory-injury contexts; a rodent study flagged stroke and seizure contexts.

Note This is not a proven human drug-interaction map, but it is a strong reason to avoid unsupervised use or co-use with CNS-active drugs.

4/5
D
Pregnancy / lactation caution3
Confidence: Medium

No human pregnancy or lactation safety evidence was found for IDRA-21.

Note For an experimental AMPA modulator, absence of data is not reassuring for pregnancy, lactation, or trying to conceive.

4/5
E
Evidence uncertainty10
Confidence: High

The evidence base is preclinical and non-human-primate, with no established human dosing or long-term safety profile.

Note This uncertainty is central to the product decision, not a minor evidence gap.

4/5
D
Animal safety concern7Ischemia model

In cultured rat hippocampal neurons and a rodent global-ischemia model, IDRA-21 worsened hippocampal neuron injury; the authors specifically highlighted stroke and seizure contexts.

Human data3Not established

No reliable human adverse-event pattern, laboratory-monitoring profile, pregnancy data, or long-term exposure dataset was found in the checked sources.

08

Legal and regulatory status

United States - research and registry context, as of June 20262

As of 2026-06-30, checked US-oriented sources did not show a compound-specific ClinicalTrials.gov trial for IDRA-21, and NCATS Inxight lists the substance without a clear approved-use pathway. Legal status varies by jurisdiction and time; verify local rules before assuming any listing is consumer-ready.

09

Practical buying and quality notes

  • IDRA-21 listings should be evaluated as research-compound listings: identity testing, purity documentation, batch traceability, and seller quality matter more than capsule count or marketing claims.1
  • Because no established human dose was found, normalized price per milligram is only a product-comparison metric. It should not be read as a practical daily-dose cost.3
10

FAQ

Is IDRA-21 a supplement?

4

Not in the normal dietary-supplement evidence sense. It is a synthetic research compound studied mostly in animal and non-human-primate models.

Is there a human IDRA-21 dose?

3

No established human dose was found. The published dose ranges are animal or non-human-primate study doses and should not be converted into a self-use protocol.

Why is animal memory evidence not enough?

10

AMPA modulation can change performance in controlled animal tasks, but human benefit, tolerability, dose selection, and risk tradeoffs need human data.

What is the main safety concern?

7

The main concern is that AMPA-positive modulation affects excitatory signaling. In a rodent ischemia model, IDRA-21 worsened hippocampal neuron injury, which makes neurologic risk context central.

11

References

  1. PubChem. IDRA-21, CID 3688. Accessed 2026-06-30.
  2. NCATS Inxight Drugs. IDRA-21, UNII 689UW7PT68. Accessed 2026-06-30.
  3. ClinicalTrials.gov. Search results for IDRA-21. Accessed 2026-06-30.
  4. Zivkovic I, Thompson DM, Bertolino M, et al. 7-Chloro-3-methyl-3-4-dihydro-2H-1,2,4 benzothiadiazine S,S-dioxide (IDRA 21): a benzothiadiazine derivative that enhances cognition by attenuating AMPA receptor desensitization. Journal of Pharmacology and Experimental Therapeutics. 1995;272(1):300-309.
  5. Thompson DM, Guidotti A, DiBella M, et al. IDRA 21, a congener of aniracetam, potently abates pharmacologically induced cognitive impairments in patas monkeys. Proceedings of the National Academy of Sciences USA. 1995;92(17):7667-7671.
  6. Arai A, Guidotti A, Costa E, et al. Effect of the AMPA receptor modulator IDRA 21 on LTP in hippocampal slices. Neuroreport. 1996;7(13):2211-2215.
  7. Yamada KA, Covey DF, Hsu CY, et al. The diazoxide derivative IDRA 21 enhances ischemic hippocampal neuron injury. Annals of Neurology. 1998;43(5):696-699.
  8. Buccafusco JJ, Weiser T, Winter K, et al. The effects of IDRA 21, a positive modulator of the AMPA receptor, on delayed matching performance by young and aged rhesus monkeys. Neuropharmacology. 2004;46(1):10-22.
  9. Losi G, Puia G, Braghiroli D, et al. IDRA-21, a positive AMPA receptor modulator, inhibits synaptic and extrasynaptic NMDA receptor mediated events in cultured cerebellar granule cells. Neuropharmacology. 2004;46(7):960-971.
  10. Black MD. Therapeutic potential of positive AMPA modulators and their relationship to AMPA receptor subunits: a review of preclinical data. Psychopharmacology. 2005;179(1):154-163.
  11. Malkova L, Kozikowski AP, Gale K, et al. The effects of huperzine A and IDRA 21 on visual recognition memory in young macaques. Neuropharmacology. 2011;60(7-8):1262-1268.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.