Post COVID Syndrome Long CovidCICR-NAM-PCSNCT07798570
Observational Study With CICR-NAM as a Food for Special Medicinal Purposes in Post-COVID Syndrome (PCS)
A study testing CICR-NAM in people with Post COVID Syndrome Long Covid, run by University Hospital Schleswig-Holstein.
Trial summary
In patients with post-COVID syndrome, changes in tryptophan metabolism, energy metabolism, and the gut microbiome may occur. In an earlier nutritional study, patients with COVID-19 recovered their physical performance more quickly when taking nicotinamide (vitamin B3). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Post COVID Syndrome Long Covid
- What is being tested?
- CICR-NAM
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 6 Sep 2026to 30 Jun 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- all sexes;
- minimum age 18 years; no upper age limit;
- post-COVID syndrome (PCS)
- serum tryptophan <55 µmol/L (UKSH reference range: 48-109 µmol/L);
- participation in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel.
Who cannot join
- Known allergies or intolerances to any component of CICR-NAM;
- inability to provide informed consent;
- pregnancy or breastfeeding;
- severe comorbid disease (especially renal insufficiency, uncontrolled autoimmune diseases, liver disease, or malignancy);
- long-term use of higher doses of medications that raise gastric pH (for example proton pump inhibitors, H2 receptor antagonists, or antacids), as an increase in pH toward approximately 7 may cause premature release of nicotinamide from CICR-NAM;
- use of supplements containing more than 20 mg nicotinamide, nicotinamide riboside, nicotinamide mononucleotide, nicotinic acid, or NAD+ per daily dose.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
In patients with post-COVID syndrome, changes in tryptophan metabolism, energy metabolism, and the gut microbiome may occur. In an earlier nutritional study, patients with COVID-19 recovered their physical performance more quickly when taking nicotinamide (vitamin B3). Patients who responded to nicotinamide also developed post-COVID syndrome less frequently. At the University Hospital Schleswig-Holstein in Kiel, special nicotinamide tablets (CICR-NAM) were developed that release the active substance selectively in the lower intestine and have been shown to be very well tolerated in several studies.
Patients with post-COVID syndrome and documented tryptophan deficiency may therefore take one tablet (500 mg) of CICR-NAM daily for up to approximately 4 months as a food for special medicinal purposes within the therapy groups of the outpatient clinic for patients with post-COVID syndrome at the University Hospital Schleswig-Holstein in Kiel. This intake is far below the Upper Level defined by the European Food Safety Authority for lifelong daily intake (900 mg per day). Therefore, there are no safety concerns. CICR-NAM intake is intended to complement the therapy group programme by supporting energy metabolism.
Read the detailed description
In the COVit-2 study (DRKS00021214), daily intake of two tablets containing a total of 1,000 mg nicotinamide (500 mg conventional nicotinamide and 500 mg controlled-ileocolonic-release nicotinamide, CICR-NAM) in patients with acute COVID-19 was associated with a significantly faster improvement in physical performance after two weeks compared with placebo. Parallel effects on the gut metagenome suggested that specifically the ileocolonically released nicotinamide from CICR-NAM tablets could counteract COVID-19-associated disturbances in the metabolism of the essential amino acid tryptophan and in the gut microbiome. In the placebo group, gene expression related to the microbial tryptophan biosynthesis pathway as well as redox and salvage pathways of the central metabolic coenzyme nicotinamide adenine dinucleotide (NAD+) was significantly increased at week 2, whereas these deviations in the metagenome were not observed in patients receiving nicotinamide supplementation.
At the 6-month follow-up of COVit-2 participants, patients who benefited from nicotinamide administration (responders) developed post-COVID syndrome significantly less frequently. Because disturbances in tryptophan metabolism are well described in both COVID-19 and PCS, a low tryptophan level may serve as an easily measurable surrogate parameter for an increased nicotinamide requirement in these conditions.
There is currently no satisfactory treatment for patients with PCS. They experience significant distress and often have a permanent disability. Given the disturbances in tryptophan metabolism and the gut microbiome observed in PCS, supplementation with CICR-NAM may help restore physical performance. Therefore, a nutritional observational study offering 500 mg/day CICR-NAM as a food for special medicinal purposes for up to approximately 4 months will be conducted within the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel for patients with documented tryptophan deficiency. A placebo-controlled clinical trial with CICR-NAM in PCS is planned, but it will not be available for recruitment in the near future. The present observational study is intended as an interim option until the clinical trial begins and is also expected to provide insights into the feasibility of such an intervention.
- Conditions
- Post COVID Syndrome Long Covid
- Being tested
- CICR-NAM
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CICR-NAMDietary supplement
Oral administration of CICR-NAM (controlled-ileocolonic-release nicotinamide) as a food for special medical purposes, one film-coated tablet (500 mg) daily for up to approximately 4 months, embedded in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel
| Study group | Role | What they receive |
|---|---|---|
| CICR-NAM Administration | Experimental | Oral administration of CICR-NAM (controlled-ileocolonic-release nicotinamide) as a food for special medical purposes, one film-coated tablet (500 mg) daily for up to approximately 4 months, embedded in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel. Receives: Dietary Supplement: CICR-NAM |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum tryptophan level
Serum tryptophan level (µmol/L) as a longitudinal marker of tryptophan and NAD+ metabolism during CICR-NAM supplementation. Assessment time points: therapy group session 1 (start of participation, screening for reduced serum tryptophan, T1), session 2 (start of supplementation, T2), session 3 (after approximately 1 month of supplementation, T3), and session 6 (end of the therapy group, after approximately 4 months, T4). Method: quantitative determination of serum tryptophan (UKSH laboratory diagnostics)
Measured: From T1 (start of participation, screening for reduced serum tryptophan) to T6 (end of the therapy group) approximately 5 month.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Sep 2026
- Study start6 Sep 2026 (estimated)
- Primary completion30 Jun 2028 (estimated)
- Study completion30 Jun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Post COVID Syndrome Long CovidStudies 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
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital Schleswig-Holstein
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07798570
- Sponsor's protocol ID
- CICR-NAM-PCS_V01_2026
- Acronym
- CICR-NAM-PCS
- Status last verified
- Aug 2026
- First submitted
- 6 Jul 2026
- Last updated
- 1 Sep 2026
- 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 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Observational Study With CICR-NAM as a Food for Special Medicinal Purposes in Post-COVID Syndrome (PCS)
- ClinicalTrials.gov ID
- NCT07798570
- Acronym / sponsor ID
- CICR-NAM-PCS / CICR-NAM-PCS_V01_2026
- Conditions
- Post COVID Syndrome Long Covid
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University Hospital Schleswig-HolsteinUniversity, hospital or other
- Study start
- 6 Sep 2026 (estimated)
- Primary completion
- 30 Jun 2028 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 1 Sep 2026 (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.
In patients with post-COVID syndrome, changes in tryptophan metabolism, energy metabolism, and the gut microbiome may occur. In an earlier nutritional study, patients with COVID-19 recovered their physical performance more quickly when taking nicotinamide (vitamin B3). Patients who responded to nicotinamide also developed post-COVID syndrome less frequently. At the University Hospital Schleswig-Holstein in Kiel, special nicotinamide tablets (CICR-NAM) were developed that release the active substance selectively in the lower intestine and have been shown to be very well tolerated in several studies.
Patients with post-COVID syndrome and documented tryptophan deficiency may therefore take one tablet (500 mg) of CICR-NAM daily for up to approximately 4 months as a food for special medicinal purposes within the therapy groups of the outpatient clinic for patients with post-COVID syndrome at the University Hospital Schleswig-Holstein in Kiel. This intake is far below the Upper Level defined by the European Food Safety Authority for lifelong daily intake (900 mg per day). Therefore, there are no safety concerns. CICR-NAM intake is intended to complement the therapy group programme by supporting energy metabolism.
Detailed description
In the COVit-2 study (DRKS00021214), daily intake of two tablets containing a total of 1,000 mg nicotinamide (500 mg conventional nicotinamide and 500 mg controlled-ileocolonic-release nicotinamide, CICR-NAM) in patients with acute COVID-19 was associated with a significantly faster improvement in physical performance after two weeks compared with placebo. Parallel effects on the gut metagenome suggested that specifically the ileocolonically released nicotinamide from CICR-NAM tablets could counteract COVID-19-associated disturbances in the metabolism of the essential amino acid tryptophan and in the gut microbiome. In the placebo group, gene expression related to the microbial tryptophan biosynthesis pathway as well as redox and salvage pathways of the central metabolic coenzyme nicotinamide adenine dinucleotide (NAD+) was significantly increased at week 2, whereas these deviations in the metagenome were not observed in patients receiving nicotinamide supplementation.
At the 6-month follow-up of COVit-2 participants, patients who benefited from nicotinamide administration (responders) developed post-COVID syndrome significantly less frequently. Because disturbances in tryptophan metabolism are well described in both COVID-19 and PCS, a low tryptophan level may serve as an easily measurable surrogate parameter for an increased nicotinamide requirement in these conditions.
There is currently no satisfactory treatment for patients with PCS. They experience significant distress and often have a permanent disability. Given the disturbances in tryptophan metabolism and the gut microbiome observed in PCS, supplementation with CICR-NAM may help restore physical performance. Therefore, a nutritional observational study offering 500 mg/day CICR-NAM as a food for special medicinal purposes for up to approximately 4 months will be conducted within the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel for patients with documented tryptophan deficiency. A placebo-controlled clinical trial with CICR-NAM in PCS is planned, but it will not be available for recruitment in the near future. The present observational study is intended as an interim option until the clinical trial begins and is also expected to provide insights into the feasibility of such an intervention.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| CICR-NAM Administration | Experimental | Dietary Supplement: CICR-NAMOral administration of CICR-NAM (controlled-ileocolonic-release nicotinamide) as a food for special medical purposes, one film-coated tablet (500 mg) daily for up to approximately 4 months, embedded in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- all sexes;
- minimum age 18 years; no upper age limit;
- post-COVID syndrome (PCS)
- serum tryptophan <55 µmol/L (UKSH reference range: 48-109 µmol/L);
- participation in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel.
Key exclusion criteria (6 listed)
- Known allergies or intolerances to any component of CICR-NAM;
- inability to provide informed consent;
- pregnancy or breastfeeding;
- severe comorbid disease (especially renal insufficiency, uncontrolled autoimmune diseases, liver disease, or malignancy);
- long-term use of higher doses of medications that raise gastric pH (for example proton pump inhibitors, H2 receptor antagonists, or antacids), as an increase in pH toward approximately 7 may cause premature release of nicotinamide from CICR-NAM;
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 |
|---|---|---|
| CICR-NAMOral administration of CICR-NAM (controlled-ileocolonic-release nicotinamide) as a food for special medical purposes, one film-coated tablet (500 mg) daily for up to approximately 4 months, embedded in the therapy groups of the PCS outpatient clinic at UKSH Campus Kiel | Dietary supplement | CICR-NAM Administration |
Primary outcome
Serum tryptophan level
Time frame: From T1 (start of participation, screening for reduced serum tryptophan) to T6 (end of the therapy group) approximately 5 month.
Serum tryptophan level (µmol/L) as a longitudinal marker of tryptophan and NAD+ metabolism during CICR-NAM supplementation. Assessment time points: therapy group session 1 (start of participation, screening for reduced serum tryptophan, T1), session 2 (start of supplementation, T2), session 3 (after approximately 1 month of supplementation, T3), and session 6 (end of the therapy group, after approximately 4 months, T4). Method: quantitative determination of serum tryptophan (UKSH laboratory diagnostics)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Sep 2026.
- 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.
Questions about this trial
What is this clinical trial studying?
A study testing CICR-NAM in people with Post COVID Syndrome Long Covid, run by University Hospital Schleswig-Holstein.
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 5 inclusion and 6 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: opening soon, as of the sponsor's last update on 1 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lennart Reinke, Dr. med. (+49 431 500-22200, lennartmichel.reinke@uksh.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serum tryptophan level (time frame: From T1 (start of participation, screening for reduced serum tryptophan) to T6 (end of the therapy group) approximately 5 month.). 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 1 Sep 2026.