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Lexicon

Cognition

Dihexa

An oral, brain-penetrant angiotensin IV analog from cognition research, with an exciting but now partly retracted evidence record.

1 min read 1 sources Titration Updated May 2026
Class
Angiotensin IV analog (nootropic)
Use
Oral (daily)
Half-life
unclear
Status
Preclinical, evidence partly retracted

Getting started

Reported dosing (research community)

Per-day figures in mg, experience values without a clinical basis. Start low.

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What is Dihexa?

Dihexa is a small, chemically stabilized molecule derived from angiotensin IV and deliberately modified to act orally and cross the blood-brain barrier. In cognition research it was studied as a candidate against dementia.

Important and honest: a prominent paper on its mechanism was retracted in 2025. The evidence is therefore thinner and more uncertain than often portrayed.

How it works

Dihexa was associated with promoting synapse formation and cognitive performance. A widely cited mechanism via the HGF/c-Met system was, however, later retracted in the relevant publication, so the exact pathway is now open.

What remains: a preclinical profile as a brain-penetrant angiotensin IV analog, without a confirmed mechanism in humans.

How to take it

Oral, once daily.

  • With some water, with or without food.
  • Rather during the day, since an activating effect is reported.

Dosing

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What the research shows

The developer work (McCoy, 2013) described dihexa as an orally available, brain-penetrant angiotensin IV analog with a memory-promoting effect in animal models. This work now carries an Expression of Concern, and a later mechanism paper was retracted in 2025. That has to be honestly factored into any assessment.

Side effects

  • Solid human data are missing.
  • A growth- and synapse-promoting signal is not automatically harmless.
  • Because of the retracted research, the uncertainty here is especially large.

Practice

  • Keep expectations low, the evidence is weaker than the hype.
  • Start low, watch closely, when in doubt wait for better data.

Storage

Store dry, cool and protected from light, out of reach of children. Keep the original container closed and mind the expiry date.

Evidence

Sources

  1. 1 Development of dihexa as an orally available, brain-penetrant angiotensin IV analog (preclinical). McCoy et al., J. of Pharmacology and Experimental Therapeutics, 2013

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Dihexa in the catalog

Sizes, prices and availability for research use. Straight from the lexicon to the product page.

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