Use of a Cysteine-rich Whey Protein Isolate in Post COVID-19 Cognitive Impairment

NCT07184398 | Completed

• 1 other identifier: 860013798-5
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Abstract Background: Post-COVID-19 cognitive impairment (PCCI), characterized by deficits in attention, memory, and executive functioning, remains a major challenge among patients with long COVID. Oxidative stress is a key contributor to this condition. Cysteine-rich whey protein isolate (CRWPI), such as Immunocal®, enhances intracellular glutathione production and may offer neuroprotective benefits. Objective: To evaluate the efficacy of Immunocal® supplementation on cognitive function, particularly attention and memory, and functional performance in individuals with ICCP. Methods: A randomized, controlled, parallel-group trial was conducted in Cali, Colombia, with 120 adults recovering from COVID-19 with mild to moderate cognitive impairment. Participants were randomly assigned to three groups: (1) immune® supplementation (CRWPI) (20 g/day), (2) neuropsychological rehabilitation, or (3) no intervention (control), for 12 weeks. Cognitive outcomes were assessed using the Montreal Cognitive Assessment (MoCA) and the NEUROPSI attention and memory test. Physical endurance was measured using the 30-second foot test (STST). Clinical symptoms evaluated through a medical assessment form, before and after the intervention, were also taken into account. Results: Both the Immunocal® and neurorehabilitation groups showed statistically significant improvements in all attention subdomains and memory types compared to the control. Immunocal® produced greater gains in divided attention and working memory, suggesting a specific advantage in cognitive domains sensitive to oxidative stress. STST performance was also significantly improved in the Immunocal® group. No significant improvements were seen in the control group. Conclusion: Immunocal® supplementation significantly improves cognitive performance, comparable to structured neurorehabilitation, in individuals with ICCP. It also shows potential to improve physical endurance, clinical symptoms, and reduce fatigue. These findings support the integration of Immunocal® as a non-pharmacological intervention for cognitive dysfunction related to long COVID.

Conditions

COVID-19 (SARS-CoV-2 Infection)

Keywords

covid-19; oxidative stress; brain fog; cognitive disorder; cysteine; whey protein

Outcome Measures

Primary Outcomes (1)

• Change in Cognitive Function

  Cognitive performance will be assessed using a standardized neuropsychological test battery evaluating memory, attention, and executive function. Scores will be compared from baseline to the end of the intervention period.

  12 weeks

Secondary Outcomes (1)

• Change in Functional Capacity (Sit-to-Stand Test)

  12 weeks

Study Arms (3)

No intervention

NO INTERVENTION

Participants will receive no specific nutritional supplementation or rehabilitation beyond routine medical follow-up. This group serves as the natural history comparator for cognitive outcomes.

Neuropsychological rehabilitation

ACTIVE COMPARATOR

Participants will undergo a structured neuropsychological rehabilitation program targeting memory, attention, and executive function deficits associated with post-COVID-19 cognitive impairment. Standardized cognitive exercises and behavioral strategies will be applied over the intervention period.

Behavioral: Cognitive rehabilitation workshops

Immunocal® (Cysteine-Rich Whey Protein Isolate)

EXPERIMENTAL

CRWPI Immunocal® (Immunotec™) was administered at a dose of 20 grams (2 sachets once daily) for 12 consecutive weeks. The research team delivered Immunocal directly to the subjects and instructed them on how to mix and self-administer it.

Other: Intervention with Consolidated Cysteine (Immunocal) 20 g per day

Interventions

Intervention with Consolidated Cysteine (Immunocal) 20 g per day OTHER

CRWPI Immunocal® (Immunotec™) was administered at a dose of 20 grams (2 sachets once daily) for 12 consecutive weeks. The research team delivered Immunocal directly to the subjects and instructed them on how to mix and self-administer it.

Immunocal® (Cysteine-Rich Whey Protein Isolate)

Cognitive rehabilitation workshops BEHAVIORAL

Neuropsychological rehabilitation consisted of in-person group sessions for 40 adults (18 years or older) to work on cognitive functions such as memory and attention. Each session lasted 45 minutes. These sessions were held three times a week for a period of 12 weeks.

Neuropsychological rehabilitation

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults ≥18 years with confirmed prior COVID-19
• with persistent cognitive symptoms
• able to complete testing
• and willing to consent.

You may not qualify if:

• Pre-existing dementia or major psychiatric illness
• whey protein allergy - participation in another cognitive trial
• severe hepatic/renal/metabolic disease, pregnancy
• or any condition interfering with participation.

Sponsors & Collaborators

• Universidad Libre seccional Cali: lead
• Immunotec Inc.: collaborator

Study Sites (1)

Doctor's office

Cali, Valle del Cauca Department, 760001, Colombia

Location

MeSH Terms

Conditions

COVID-19; Mental Fatigue; Cognitive Dysfunction

Interventions

Methods

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases; Fatigue; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavioral Symptoms; Behavior; Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Investigative Techniques

Study Officials

• Ingrid Mena, Neuropsychologist

  Universidad Libre

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: This is an open-label study. No masking will be applied. All participants, care providers, and investigators will be aware of the treatment being administered. Outcome assessors will also be unblinded.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Neuropsychologist

Model Details: This open-label study evaluates the use of a cysteine-rich whey protein isolate (Immunocal®) in patients with post-COVID-19 cognitive impairment. Oxidative stress and glutathione depletion are believed to contribute to persistent neurological and respiratory symptoms. Since direct glutathione supplementation is poorly absorbed, Immunocal® provides bioavailable cystine, which is converted to cysteine-the rate-limiting precursor for intracellular glutathione synthesis. Daily supplementation aims to restore redox balance, reduce neuroinflammation, and improve cognitive performance, fatigue, and quality of life in COVID-19 survivors. Outcomes include validated cognitive tests, fatigue scales, and biomarkers of oxidative stress and inflammation to explore clinical and mechanistic effects.

Study Record Dates

• First Submitted: September 9, 2025
• First Posted: September 19, 2025
• Study Start: July 1, 2024
• Primary Completion: September 30, 2024
• Study Completion: January 1, 2025
• Last Updated: September 24, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CO (1)