Randomized Clinical Trial of How Long-Term Glutathione Supplementation Offers Protection from Oxidative Damage and Improves HbA1c in Elderly Type 2 Diabetic Patients.

Kalamkar S, Acharya J, Kolappurath Madathil A, Gajjar V, Divate U, Karandikar-Iyer S, Goel P, Ghaskadbi S

Antioxidants (Basel, Switzerland)23 May 2022Cited by 25 (Europe PMC)

PMID35624890PMCIDPMC9137531DOI10.3390/antiox11051026PepBankPUB-35624890

Summary

Complications in type 2 diabetes (T2D) arise from hyperglycemia-induced oxidative stress. Here, we examined the effectiveness of supplementation with the endogenous antioxidant glutathione (GSH) during anti-diabetic treatment. A total of 104 non-diabetic and 250 diabetic individuals on anti-diabetic therapy, of either sex and aged between 30 and 78 years, were recruited. A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months. Fasting and PP glucose, insulin, HbA1c, GSH, oxidized glutathione (GSSG), and 8-hydroxy-2-deoxy guanosine (8-OHdG) were measured upon recruitment and after three and six months of supplementation. Statistical significance and effect size were assessed longitudinally across all arms. Blood GSH increased (Cohen’s d = 1.01) and 8-OHdG decreased (Cohen’s d = −1.07) significantly within three months (p < 0.001) in diabetic individuals. A post hoc sub-group analysis showed that HbA1c (Cohen’s d = −0.41; p < 0.05) and fasting insulin levels (Cohen’s d = 0.56; p < 0.05) changed significantly in diabetic individuals above 55 years. GSH supplementation caused a significant increase in blood GSH and helped maintain the baseline HbA1c overall. These results suggest GSH supplementation is of considerable benefit to patients above 55 years, not only supporting decreased glycated hemoglobin (HbA1c) and 8-OHdG but also increasing fasting insulin. The clinical implication of our study is that the oral administration of GSH potentially complements anti-diabetic therapy in achieving better glycemic targets, especially in the elderly population.

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study5

5 results from studies that gave the peptide. 5 results from people.

01HumanRandomized controlled trialPharmacokinetics
In diabetic individuals, GSH supplementation increased blood GSH significantly within three months.
In plain wordsIn diabetic individuals, glutathione supplementation increased blood glutathione from baseline within three months.
Peptide
Glutathione
Outcome
IncreaseBlood GSH
Study
n = 125
Outcome group
Pharmacokinetics · Metabolic and weight
Studied dose
500 mg daily · oral · six monthsAs given in this study (human).
Measurements
Cohen’s d
1.01 NA
blood GSH
P value for blood GSH change
< 0.001 NA
diabetic individuals; blood GSH increase within three months during GSH supplementation
Source sentences
Summary
Blood GSH increased (Cohen’s d = 1.01) and 8-OHdG decreased (Cohen’s d = −1.07) significantly within three months (p < 0.001) in diabetic individuals.
1 context sentence(design, population, supporting numbers)
Summary · context
A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months.
Show in the study text Report a problemFND-3562489001
02HumanRandomized controlled trialEfficacy outcome
In diabetic individuals, GSH supplementation decreased 8-OHdG significantly within three months.
In plain wordsIn diabetic individuals, glutathione supplementation decreased a marker of oxidative DNA damage from baseline within three months.
Peptide
Glutathione
Outcome
Decrease8-OHdG
Study
n = 125
Outcome group
Oxidative stress · Metabolic and weight
Studied dose
500 mg daily · oral · six monthsAs given in this study (human).
Measurements
Cohen’s d
−1.07 NA
8-OHdG
P value for 8-OHdG change
< 0.001 NA
diabetic individuals; 8-OHdG decrease within three months during GSH supplementation
Source sentences
Summary
Blood GSH increased (Cohen’s d = 1.01) and 8-OHdG decreased (Cohen’s d = −1.07) significantly within three months (p < 0.001) in diabetic individuals.
1 context sentence(design, population, supporting numbers)
Summary · context
A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months.
Show in the study text Report a problemFND-3562489002
03HumanRandomized controlled trialEfficacy outcome
In diabetic individuals, GSH supplementation maintained baseline HbA1c overall.
In plain wordsIn diabetic individuals, glutathione supplementation maintained HbA1c at baseline levels overall.
Peptide
Glutathione
Outcome
No significant changeOverall HbA1c
Study
n = 125
Outcome group
Glycemic control · Metabolic and weight
Studied dose
500 mg daily · oral · six monthsAs given in this study (human).
Source sentences
Summary
GSH supplementation caused a significant increase in blood GSH and helped maintain the baseline HbA1c overall.
1 context sentence(design, population, supporting numbers)
Summary · context
A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months.
Show in the study text Report a problemFND-3562489005
04HumanRandomized controlled trialEfficacy outcome
In diabetic individuals above 55 years, post hoc analysis found decreased HbA1c during GSH supplementation.
In plain wordsIn diabetic individuals above 55 years, glutathione supplementation decreased HbA1c from baseline in a post hoc analysis.
Peptide
Glutathione
Outcome
DecreaseHbA1c above 55 years
Study
n: not reported in source
Outcome group
Glycemic control · Metabolic and weight
Studied dose
500 mg daily · oral · six monthsAs given in this study (human).
Measurements
Cohen’s d
−0.41 NA
HbA1c
P value for HbA1c change
< 0.05 NA
post hoc subgroup above 55 years; HbA1c change during GSH supplementation
Source sentences
Summary
A post hoc sub-group analysis showed that HbA1c (Cohen’s d = −0.41; p < 0.05) and fasting insulin levels (Cohen’s d = 0.56; p < 0.05) changed significantly in diabetic individuals above 55 years.
1 context sentence(design, population, supporting numbers)
Summary · context
A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months.
Show in the study text Report a problemFND-3562489003
05HumanRandomized controlled trialEfficacy outcome
In diabetic individuals above 55 years, post hoc analysis found increased fasting insulin during GSH supplementation.
In plain wordsIn diabetic individuals above 55 years, glutathione supplementation increased fasting insulin from baseline in a post hoc analysis.
Peptide
Glutathione
Outcome
IncreaseFasting insulin above 55 years
Study
n: not reported in source
Outcome group
Glycemic control · Metabolic and weight
Studied dose
500 mg daily · oral · six monthsAs given in this study (human).
Measurements
Cohen’s d
0.56 NA
fasting insulin
P value for fasting insulin change
< 0.05 NA
post hoc subgroup above 55 years; fasting insulin change during GSH supplementation
Source sentences
Summary
A post hoc sub-group analysis showed that HbA1c (Cohen’s d = −0.41; p < 0.05) and fasting insulin levels (Cohen’s d = 0.56; p < 0.05) changed significantly in diabetic individuals above 55 years.
1 context sentence(design, population, supporting numbers)
Summary · context
A total of 125 diabetic patients were additionally given 500 mg oral GSH supplementation daily for a period of six months.
Show in the study text Report a problemFND-3562489004

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Version history

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Version 2Current
14 Oct 2026, 05:02 UTC
Study results updated
Version 1
14 Oct 2026, 01:46 UTC
First added · source update from Europe PMC

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