{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=tetrahydrobiopterin+%28BH4%29&page=2",
    "query": {
      "intervention": "tetrahydrobiopterin (BH4)",
      "page": 2
    },
    "page_size": 10
  },
  "pagination": {
    "page": 2,
    "page_size": 10,
    "total_count": 61,
    "total_pages": 7,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=tetrahydrobiopterin+%28BH4%29&page=3&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=tetrahydrobiopterin+%28BH4%29&page=1&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-12T10:25:05.603Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT02353312",
      "title": "Rhode Island Diastolic Dysfunction - Heart Failure",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Heart Failure",
        "Cardiovascular Disease"
      ],
      "interventions": [
        {
          "name": "Kuvan",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Providence VA Medical Center",
      "sponsor_class": "FED",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 28,
      "start_date": "2015-03",
      "completion_date": "2018-12",
      "has_results": true,
      "last_update_posted_date": "2025-07-03",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Providence, Rhode Island",
      "locations": [
        {
          "city": "Providence",
          "state": "Rhode Island"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02353312"
    },
    {
      "nct_id": "NCT00986973",
      "title": "Fluorodeoxyglucose Positron Emission Tomography (FDG PET) Findings in Patients With Phenylketonuria Before and After KUVAN Therapy",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "Sapropterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Children's Hospital of Philadelphia",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 6,
      "start_date": "2010-03",
      "completion_date": "2011-09",
      "has_results": true,
      "last_update_posted_date": "2015-06-08",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00986973"
    },
    {
      "nct_id": "NCT00027157",
      "title": "Determination of Variances in Exhaled Nitric Oxide Output in Normal Healthy Male Volunteers Consuming High and Low Nitrate/Nitrite Diets",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Healthy"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "National Heart, Lung, and Blood Institute (NHLBI)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "MALE",
        "summary": "Male only"
      },
      "enrollment_count": 18,
      "start_date": "2000-04",
      "completion_date": "2003-04",
      "has_results": false,
      "last_update_posted_date": "2008-03-04",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Bethesda, Maryland",
      "locations": [
        {
          "city": "Bethesda",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00027157"
    },
    {
      "nct_id": "NCT01398943",
      "title": "Nitric Oxide Bioavailability in Chronic Obstructive Pulmonary Disease (COPD)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Pulmonary Disease, Chronic Obstructive"
      ],
      "interventions": [
        {
          "name": "Tetrahydrobiopterin (BH4)",
          "type": "DRUG"
        },
        {
          "name": "Antioxidant Cocktail",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Augusta University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 60,
      "start_date": "2010-09",
      "completion_date": "2015-06",
      "has_results": true,
      "last_update_posted_date": "2017-12-11",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Augusta, Georgia",
      "locations": [
        {
          "city": "Augusta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01398943"
    },
    {
      "nct_id": "NCT00208780",
      "title": "Effects of Tetrahydrobiopterin on Blood Pressure",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Hypertension"
      ],
      "interventions": [
        {
          "name": "Tetrahydrobiopterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Emory University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "18 Years to 75 Years"
      },
      "enrollment_count": 24,
      "start_date": "2004-12",
      "completion_date": "2005-12",
      "has_results": false,
      "last_update_posted_date": "2013-11-18",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Atlanta, Georgia",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00208780"
    },
    {
      "nct_id": "NCT04054973",
      "title": "L-arginine Study for Persistent Symptoms of Schizophrenia",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Schizo Affective Disorder",
        "Schizophrenia"
      ],
      "interventions": [
        {
          "name": "L-arginine",
          "type": "DRUG"
        },
        {
          "name": "Sapropterin Dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Massachusetts, Worcester",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "65 Years",
        "sex": "ALL",
        "summary": "18 Years to 65 Years"
      },
      "enrollment_count": 0,
      "start_date": "2019-09-11",
      "completion_date": "2021-12-31",
      "has_results": false,
      "last_update_posted_date": "2022-01-20",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Worcester, Massachusetts",
      "locations": [
        {
          "city": "Worcester",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04054973"
    },
    {
      "nct_id": "NCT01617070",
      "title": "Effects of Kuvan on Melatonin Secretion",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Phenylketonuria (PKU)"
      ],
      "interventions": [
        {
          "name": "Kuvan",
          "type": "DRUG"
        },
        {
          "name": "Large Neutral Amino Acid Therapy",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Southern California",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 10,
      "start_date": "2012-05",
      "completion_date": "2014-12",
      "has_results": true,
      "last_update_posted_date": "2016-11-18",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Los Angeles, California",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01617070"
    },
    {
      "nct_id": "NCT00838435",
      "title": "Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": "6 Years",
        "sex": "ALL",
        "summary": "Up to 6 Years"
      },
      "enrollment_count": 95,
      "start_date": "2009-02",
      "completion_date": "2018-09-14",
      "has_results": true,
      "last_update_posted_date": "2020-12-22",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 12,
      "location_summary": "La Jolla, California • Orange, California • Tampa, Florida + 9 more",
      "locations": [
        {
          "city": "La Jolla",
          "state": "California"
        },
        {
          "city": "Orange",
          "state": "California"
        },
        {
          "city": "Tampa",
          "state": "Florida"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00838435"
    },
    {
      "nct_id": "NCT00625820",
      "title": "Tetrahydrobiopterin in Patients With Chronic Kidney Disease (CKD) and Albuminuria",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Kidney Disease",
        "Albuminuria"
      ],
      "interventions": [
        {
          "name": "6R BH4",
          "type": "DRUG"
        },
        {
          "name": "Vitamin C",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Michigan",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "18 Years to 75 Years"
      },
      "enrollment_count": 17,
      "start_date": "2008-05",
      "completion_date": "2008-09",
      "has_results": true,
      "last_update_posted_date": "2016-10-18",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Ann Arbor, Michigan",
      "locations": [
        {
          "city": "Ann Arbor",
          "state": "Michigan"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00625820"
    },
    {
      "nct_id": "NCT01425528",
      "title": "Study of Kuvan Treatment in Adults With GTPCH Deficiency",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "GTP Cyclohydrolase Deficiency"
      ],
      "interventions": [
        {
          "name": "Sapropterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Utah",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 12,
      "start_date": "2011-08",
      "completion_date": "2013-08",
      "has_results": true,
      "last_update_posted_date": "2025-04-01",
      "last_synced_at": "2026-10-12T10:25:05.603Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01425528"
    }
  ]
}