COVID-19 (SARS-CoV-2 Infection)NCT07184398
Use of a Cysteine-rich Whey Protein Isolate in Post COVID-19 Cognitive Impairment
A study testing Intervention with Consolidated Cysteine (Immunocal) 20 g per day and Cognitive rehabilitation workshops in people with COVID-19 (SARS-CoV-2 Infection), run by Universidad Libre seccional Cali at 1 site in Colombia.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- COVID-19 (SARS-CoV-2 Infection)
- What is being tested?
- Intervention with Consolidated Cysteine (Immunocal) 20 g per day and Cognitive rehabilitation workshops
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteColombia
- Study dates
- 1 Jul 2024to 1 Jan 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults ≥18 years with confirmed prior COVID-19
- with persistent cognitive symptoms
- able to complete testing
- and willing to consent.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Use of a Cysteine-rich Whey Protein Isolate (Immunocal®) in Post COVID-19 Cognitive Impairment
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.
Read more
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.
Read the detailed description
Study Design and Participants This randomized, controlled, parallel-group trial included subjects at least 18 years of age in Cali, Colombia, who recovered from COVID-19 infection and presented with mild to moderate cognitive impairment and no history of Immunocal administration. Subjects with a history of cerebrovascular or cardiovascular disease and current or previous use of Immunocal were excluded from screening. Ethical approval was obtained from the IRB of the Universidad Libre and informed consent was obtained.
Sampling and protocol A consecutive non-probabilistic sampling was performed. For this study, a target sample of 120 subjects was selected to achieve a 95% confidence level. A double-blind randomization process was used to divide subjects into three groups of 40 participants as follows: 1. CRWPI (Immunocal®) supplementation; 2. Structured neuropsychological rehabilitation (Neurorehabilitation), and no intervention (control).
A group of neuropsychologists with experience in the application of cognitive tools and neuropsychological rehabilitation were responsible for the evaluation and management of the neuropsychological phase of the study. Neuropsychological rehabilitation consisted of 45-minute face-to-face group sessions that were conducted three times a week over a 12-week period. After 12 weeks, a neuropsychological evaluation was completed on each subject.
CRWPI Immunocal® (Immunotec ™) was administered at a dose of 20 grams (2 sachets once daily) for 12 consecutive weeks. The research team delivered the Immunocal directly to the subjects and instructed them how to mix and self-administer it.
Pre-test cognitive functioning was assessed using NEUROPSI attention and memory, while only NEUROPSI attention and memory were used to assess the same cognitive domains at 12 weeks.
The main objective of NEUROPSI Attention and Memory is to assess a broad spectrum of cognitive functions, including spatial, temporal and personal orientation; attention and concentration; working memory; verbal and visual memory, and executive and motor functions. The NEUROPSI Attention and Memory test considers age and schooling for the acquisition of quantitative and qualitative data and classifies amnesic and attentional alterations into four different categories.
The 30-second sit-stand (STST) test is a widely used assessment designed to assess lower-body strength and functional endurance.19 It measures how many complete stops a person can complete from a seated position in 30 seconds, without using their arms for support. This test provides valuable information about muscle strength and balance, making it a practical tool for monitoring physical performance and the effectiveness of interventions such as exercise programs or nutritional supplements. STST is often used to assess fatigue in the muscles of the lower extremities and trunk. This test was performed on all available participants after the intervention period was completed.
The participants were also evaluated before and after the intervention by the doctors of the research group, through a medical assessment form where all clinical symptoms due to the virus were recorded.
- Conditions
- COVID-19 (SARS-CoV-2 Infection)
- Being tested
- Intervention with Consolidated Cysteine (Immunocal) 20 g per day, Cognitive rehabilitation workshops
- Keywords
- covid-19, oxidative stress, brain fog, cognitive disorder, cysteine, whey protein
- Medical subject headings
- COVID-19, Mental Fatigue, Cognitive Dysfunction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intervention with Consolidated Cysteine (Immunocal) 20 g per dayOther
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.
Cognitive rehabilitation workshopsBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: Other: Intervention with Consolidated Cysteine (Immunocal) 20 g per day |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 12 weeks
Secondary outcomes (1)
Change in Functional Capacity (Sit-to-Stand Test)
Functional capacity will be measured by the 30-second sit-to-stand test. The number of repetitions completed will be compared between baseline and study completion.
Measured: 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2025
- Study start1 Jul 2024
- Primary completion30 Sep 2024
- Study completion1 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19 (SARS-CoV-2 Infection)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 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.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 120 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad Libre seccional Cali
- Sponsor type
- University, hospital or other
- Collaborators
- Immunotec Inc.
- Responsible party
- Principal investigator, Ingrid Mena, Universidad Libre seccional Cali
- Investigators
- Ingrid Mena, Neuropsychologist, Principal investigator, Universidad Libre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07184398
- Sponsor's protocol ID
- 860013798-5
- Status last verified
- Sep 2025
- First submitted
- 9 Sep 2025
- Last updated
- 24 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of a Cysteine-rich Whey Protein Isolate (Immunocal®) in Post COVID-19 Cognitive Impairment
- ClinicalTrials.gov ID
- NCT07184398
- Acronym / sponsor ID
- 860013798-5
- Conditions
- COVID-19 (SARS-CoV-2 Infection)
- Keywords
- covid-19, oxidative stress, brain fog, cognitive disorder, cysteine, whey protein
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- Universidad Libre seccional CaliUniversity, hospital or other
- Collaborators
- Immunotec Inc.
- Study start
- 1 Jul 2024 (actual)
- Primary completion
- 30 Sep 2024 (actual)
- Study completion
- 1 Jan 2025 (actual)
- First posted
- 19 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Study Design and Participants This randomized, controlled, parallel-group trial included subjects at least 18 years of age in Cali, Colombia, who recovered from COVID-19 infection and presented with mild to moderate cognitive impairment and no history of Immunocal administration. Subjects with a history of cerebrovascular or cardiovascular disease and current or previous use of Immunocal were excluded from screening. Ethical approval was obtained from the IRB of the Universidad Libre and informed consent was obtained.
Sampling and protocol A consecutive non-probabilistic sampling was performed. For this study, a target sample of 120 subjects was selected to achieve a 95% confidence level. A double-blind randomization process was used to divide subjects into three groups of 40 participants as follows: 1. CRWPI (Immunocal®) supplementation; 2. Structured neuropsychological rehabilitation (Neurorehabilitation), and no intervention (control).
A group of neuropsychologists with experience in the application of cognitive tools and neuropsychological rehabilitation were responsible for the evaluation and management of the neuropsychological phase of the study. Neuropsychological rehabilitation consisted of 45-minute face-to-face group sessions that were conducted three times a week over a 12-week period. After 12 weeks, a neuropsychological evaluation was completed on each subject.
CRWPI Immunocal® (Immunotec ™) was administered at a dose of 20 grams (2 sachets once daily) for 12 consecutive weeks. The research team delivered the Immunocal directly to the subjects and instructed them how to mix and self-administer it.
Pre-test cognitive functioning was assessed using NEUROPSI attention and memory, while only NEUROPSI attention and memory were used to assess the same cognitive domains at 12 weeks.
The main objective of NEUROPSI Attention and Memory is to assess a broad spectrum of cognitive functions, including spatial, temporal and personal orientation; attention and concentration; working memory; verbal and visual memory, and executive and motor functions. The NEUROPSI Attention and Memory test considers age and schooling for the acquisition of quantitative and qualitative data and classifies amnesic and attentional alterations into four different categories.
The 30-second sit-stand (STST) test is a widely used assessment designed to assess lower-body strength and functional endurance.19 It measures how many complete stops a person can complete from a seated position in 30 seconds, without using their arms for support. This test provides valuable information about muscle strength and balance, making it a practical tool for monitoring physical performance and the effectiveness of interventions such as exercise programs or nutritional supplements. STST is often used to assess fatigue in the muscles of the lower extremities and trunk. This test was performed on all available participants after the intervention period was completed.
The participants were also evaluated before and after the intervention by the doctors of the research group, through a medical assessment form where all clinical symptoms due to the virus were recorded.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- 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.
| Arm | Type | Receives |
|---|---|---|
| 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 | Behavioral: Cognitive rehabilitation workshopsParticipants 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. |
| Immunocal® (Cysteine-Rich Whey Protein Isolate) | Experimental | Other: Intervention with Consolidated Cysteine (Immunocal) 20 g per dayCRWPI 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. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults ≥18 years with confirmed prior COVID-19
- with persistent cognitive symptoms
- able to complete testing
- and willing to consent.
Key exclusion criteria (4 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intervention with Consolidated Cysteine (Immunocal) 20 g per dayCRWPI 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 | Immunocal® (Cysteine-Rich Whey Protein Isolate) |
| Cognitive rehabilitation workshopsNeuropsychological 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. | Behavioural | Neuropsychological rehabilitation |
Primary outcome
Change in Cognitive Function
Time frame: 12 weeks
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.
1 secondary outcome
Change in Functional Capacity (Sit-to-Stand Test)
Time frame: 12 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ingrid Mena, Neuropsychologist principal investigator
Universidad Libre
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Intervention with Consolidated Cysteine (Immunocal) 20 g per day and Cognitive rehabilitation workshops in people with COVID-19 (SARS-CoV-2 Infection), run by Universidad Libre seccional Cali at 1 site in Colombia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Colombia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Cognitive Function (time frame: 12 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2025.