Independent · non-commercial · publishes on a quarterly cycle|Current cycle 2026 Q3
Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Indication assessment · §2

Cognitive performance and neuroprotection — evidence across compounds

Every compound the Institute assesses in cognitive performance and neuroprotection, with its certainty rating.

Document identifier
CEI-IN-27/2
Series
Indication assessment
Version
2.3
Published
15 Feb 2025
Last reviewed
15 Feb 2025
Next review
15 Feb 2027
Identifier
10.71829/cei.ind.27
Certainty
Not rated
Cycle
2025 Q1
ICD-11
MB21
Category
Neuropsychiatric

§2Evidence across compounds

Every compound the Institute assesses in this indication, with the effect as recorded, the certainty rating and the contributing trials. Effects are reported on the anchor outcome where the contributing trials measured it and on the outcome the trial actually reported where they did not.

Table 1. Compounds assessed in cognitive performance and neuroprotection, ordered by certainty.

CompoundEffect as recordedInterval as reportedCertaintyTrials
GlutathioneEndogenous tripeptide thiol antioxidantSmall randomised trials of intravenous and intranasal glutathione in Parkinson disease reported no significant benefit over placebo on motor endpointsnegative results in small samplesLow1
DSIPEndogenous nonapeptideNo assessable evidence identifiedVery low0
EpithalonSynthetic tetrapeptideNo assessable evidence identifiedVery low0
NAD+ (nicotinamide adenine dinucleotide)Endogenous pyridine dinucleotide coenzymeNo assessable randomised evidence identifiedVery low0
SelankSynthetic tuftsin analogue heptapeptideRussian clinical studies report anxiolytic effect comparable to benzodiazepines without sedation or withdrawalnot extractable to the Institute's standardVery low1
SemaxSynthetic ACTH(4-10) analogue heptapeptideRussian clinical studies report functional improvement after ischaemic stroke and in cognitive disordersnot extractable to the Institute's standard from the available reportsVery low2
Thymosin alpha-128-residue N-acetylated thymic polypeptideNo evidence identifiedNot rated0
Estimates in this table are not on a common scale and must not be subtracted from one another. Where a comparison between two compounds has been made directly, it appears in a synthesis and not here.
Compounds assessed in CognitionPoint estimates with confidence intervals for each contributing study, plotted against the line of no effect.0.00.20.40.60.8Standardised direction and relative magnitudeCompoundEffect as recordedGlutathioneLow certaintySmall randomised trials of…DSIPVery low certaintyNo assessable evidence identifiedEpithalonVery low certaintyNo assessable evidence identifiedNAD+ (nicotinamide…Very low certaintyNo assessable randomised evidence…SelankVery low certaintyRussian clinical studies report…SemaxVery low certaintyRussian clinical studies report…Thymosin alpha-1Not rated certaintyNo evidence identified
Moderate or high certaintyLow or very low certainty
Figure 1. Illustrative. Compounds assessed in this indication, plotted on a common standardised axis so that direction and relative magnitude can be compared at a glance. The estimates are not on a common natural scale and the intervals are the Institute's standardised representation of the reported precision rather than published confidence intervals.

§2.1Syntheses bearing on this indication

References cited on this page

References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.

  1. D’Hondt M, Bracke N, Taevernier L, Gevaert B, Verbeke F, Wynendaele E, De Spiegeleer B. Related impurities in peptide medicines. Journal of Pharmaceutical and Biomedical Analysis 2014;101:2–30. doi:10.1016/j.jpba.2014.06.012 · PMID 25044089
  2. Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharmaceutical Research 2010;27(4):544–575. doi:10.1007/s11095-009-0045-6 · PMID 20143256

Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.

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