A preliminary, randomized, double-blind, placebo-controlled trial of L-carnosine to improve cognition in schizophrenia.

Chengappa KN, Turkin SR, DeSanti S, Bowie CR, Brar JS, Schlicht PJ, Murphy SL, Hetrick ML, Bilder R, Fleet D

Schizophrenia research23 Oct 2012Cited by 73 (Europe PMC)

PMID23099060DOI10.1016/j.schres.2012.10.001PepBankPUB-23099060

Publisher page PubMedAsk about this study

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study7

7 results from studies that gave the peptide. 7 results from people.

01HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, adjunctive L‑carnosine significantly shortened non-reversal set-shifting reaction times versus placebo.
In plain wordsIn adults with schizophrenia, L‑carnosine improved non-reversal test speed compared with placebo.
Peptide
L-carnosine
Outcome
DecreaseNon-reversal set-shifting reaction time
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
The L-carnosine group performed significantly faster on non-reversal condition trials of the set-shifting test compared with placebo but reversal reaction times and errors were not significantly different between treatments.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906001
02HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, reversal reaction times did not differ significantly between L‑carnosine and placebo.
In plain wordsIn adults with schizophrenia, reversal reaction times did not differ significantly between L‑carnosine and placebo.
Peptide
L-carnosine
Outcome
No significant changeReversal reaction time
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
The L-carnosine group performed significantly faster on non-reversal condition trials of the set-shifting test compared with placebo but reversal reaction times and errors were not significantly different between treatments.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906002
03HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, set-shifting errors did not differ significantly between L‑carnosine and placebo.
In plain wordsIn adults with schizophrenia, test errors did not differ significantly between L‑carnosine and placebo.
Peptide
L-carnosine
Outcome
No significant changeSet-shifting errors
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
The L-carnosine group performed significantly faster on non-reversal condition trials of the set-shifting test compared with placebo but reversal reaction times and errors were not significantly different between treatments.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906003
04HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, L‑carnosine significantly improved strategic target detection efficiency versus placebo.
In plain wordsIn adults with schizophrenia, L‑carnosine improved strategic test efficiency compared with placebo.
Peptide
L-carnosine
Outcome
IncreaseStrategic efficiency
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
On the strategic target detection test, the L-carnosine group displayed significantly improved strategic efficiency and made fewer perseverative errors compared with placebo.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906004
05HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, L‑carnosine reduced perseverative errors on strategic target detection versus placebo.
In plain wordsIn adults with schizophrenia, L‑carnosine reduced repeated test errors compared with placebo.
Peptide
L-carnosine
Outcome
DecreasePerseverative errors
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
On the strategic target detection test, the L-carnosine group displayed significantly improved strategic efficiency and made fewer perseverative errors compared with placebo.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906005
06HumanRandomized controlled trialEfficacy outcome
In adults with schizophrenia, other cognitive tests showed no significant differences between L‑carnosine and placebo.
In plain wordsIn adults with schizophrenia, other cognitive tests showed no significant differences between L‑carnosine and placebo.
Peptide
L-carnosine
Outcome
No significant changeOther cognitive tests
Study
n = 75
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Source sentences
Summary
Other cognitive tests showed no significant differences between treatments.
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906006
07HumanRandomized controlled trialSafety outcome
In adults with schizophrenia, adverse events were reported by 30% with L‑carnosine versus 14% with placebo.
In plain wordsIn adults with schizophrenia, adverse events were more frequent with L‑carnosine than placebo.
Peptide
L-carnosine
Outcome
IncreaseAdverse events
Study
n = 75
Comparator
Placebo
Outcome group
Adverse events · Whole body
Studied dose
2 g/day · 3 monthsAs given in this study (human).
Measurements
Adverse events
30%
L-carnosine
Adverse events
14%
placebo
Source sentences
Summary
The carnosine group reported more adverse events (30%) compared with the placebo group (14%).
1 context sentence(design, population, supporting numbers)
Summary · context
Seventy-five symptomatically stable adults with chronic schizophrenia were randomly assigned to L-carnosine as adjunctive treatment (2 g/day) or a matched placebo in a double-blind manner for 3 months.
Report a problemFND-2309906007

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
27 Oct 2026, 18:20 UTC
Study results updated
Version 1
27 Oct 2026, 16:32 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

PepBank is a research reference. Talk to a doctor before you use any peptide.